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skipmac 18-09-2019 13:26

Oil leak from valve cover
 
Had a small but persistent oil leak from the valve cover which I wanted to address before heading north for the summer.


The first mistake I made was paying a mechanic to replace the gasket while I devoted my time to provisioning the boat. The result was it leaks more now than before.


Details:


- Like most boat engines it is mounted at an angle.
- The leak seems to be only at the low end of the cover but then that's where oil will collect when the engine is running. It appears as small puddles on top of the head right next to the cover that then run down the block and all over the pan under the engine.
- There are no gouges, gaps or obvious problems with the head or cover. Checked both with a straight edge and no noticeable warping on either.
- The "expert mechanic" cleaned head and cover, applied some kind of goop and installed a new gasket. The goop is red and has the consistency of silicone.


Silly me thought installing a new gasket was all it took but apparently not.


So how to fix this? Maybe use more or different goop? I have looked at the local NAPA and determined there's about 4,000 different kinds of Permantex. Some to actually make gaskets, some to seal a gasket, some fuel proof, temperature proof. Maybe I need to find a grade of Permatex that's idiot proof.


One more thing, talked to the excellent mechanic that works on my Yamaha outboard and he suggested a clogged vent hose from the cover to the crankcase could cause a leak.


Anything else I can check. Things to look for that might contribute to the problem?


Thanks
Skip

rbk 18-09-2019 13:34

Re: Oil leak from valve cover
 
We went to a nitrile gasket and new rubbers in the valve cover. The new rubber inserts were very soft compared to the old ones so I ended up going back after a few hours of motoring and retorqued them until no leak. Problem with permatex on the valve cover, is you should really be in there annually doing regular checks. Not sure which engine you have but see if a nitrile gasket is available as theyre pretty cheap and better than cork and really crank down on the cover bolts but don't distort the cover. I was really surprised as how much the new rubbers compressed without damaging the cover or the inserts.

Clogged vent is an easy check, but also if the air filter is equipped make sure it is intact. A torn filter could cause lack of suction on the vent hose and increase pressure.

skipmac 18-09-2019 13:38

Re: Oil leak from valve cover
 
HI RBK,


Thanks for reminding me to mention this. The engine is a Westerbeke W58 which is just a Perkins 4-154 painted red.


The valve cover attaches to four studs coming up from the centerline of the head, not with bolts around the edge.

skipmac 18-09-2019 13:46

Re: Oil leak from valve cover
 
Also, the new gasket I used is not cork but some kind of rubbery material so probably nitrile.


I did check the vent on the cover and that's clear. Not at the boat but will check the hose to the crankcase tomorrow.


Hopefully not making myself sound too ignorant but why would I need to check under the valve cover every year? Adjusting the valves is all I can think but I might run the engine 40 hours a year (it's a sailboat :wink:) so assumed the valves would be OK.

sailormed 18-09-2019 13:51

Re: Oil leak from valve cover
 
My favorite gasket goop in this case is Hylomar Universal Blue.

geoleo 18-09-2019 13:51

Re: Oil leak from valve cover
 
Quote:

Originally Posted by skipmac (Post 2979513)
Also, the new gasket I used is not cork but some kind of rubbery material so probably nitrile.


I did check the vent on the cover and that's clear. Not at the boat but will check the hose to the crankcase tomorrow.


Hopefully not making myself sound too ignorant but why would I need to check under the valve cover every year? Adjusting the valves is all I can think but I might run the engine 40 hours a year (it's a sailboat :wink:) so assumed the valves would be OK.

Maybe make a "stiffening" bar from a steel angle that can put more pressure on the valve cover . say a steel angle that has holes for all the 4 c/l bolts and can be arranged to put pressure on the ends of the valve cover. :thumb:

rbk 18-09-2019 13:53

Re: Oil leak from valve cover
 
We have a 4108 so might be similar. Same two center studs run up through the cover and (they may be painted) rubber insets with washers on top to compress the cover (these get hard and don't work as well over time)

https://www.parts4engines.com/perkin...tud-seals-set/

Sounds like you have a nitrile gasket already but look at the above link, the 4 rubber bits (stud seals) are the inserts for the valve cover. As for annual maintenance, valve tip clearances as well as check the collets for proper seating, check head bolt torque, broken/cracked springs ect. Catch any of those early and you'll save a world of hurt and takes no time to take the cover off IMO. Good luck

skipmac 18-09-2019 14:05

Re: Oil leak from valve cover
 
Quote:

Originally Posted by rbk (Post 2979519)
We have a 4108 so might be similar. Same two center studs run up through the cover and (they may be painted) rubber insets with washers on top to compress the cover (these get hard and don't work as well over time)

https://www.parts4engines.com/perkin...tud-seals-set/

Sounds like you have a nitrile gasket already but look at the above link, the 4 rubber bits (stud seals) are the inserts for the valve cover. As for annual maintenance, valve tip clearances as well as check the collets for proper seating, check head bolt torque, broken/cracked springs ect. Catch any of those early and you'll save a world of hurt and takes no time to take the cover off IMO. Good luck


Thanks. Yes sounds like the same setup, just four studs instead of two. I did check the rubber inserts and they're good. The leak is definitely around the bottom of the valve cover.


From your comments I have clearly been neglecting some inspection details in the valve train area. :frown:

skipmac 18-09-2019 14:07

Re: Oil leak from valve cover
 
Quote:

Originally Posted by geoleo (Post 2979517)
Maybe make a "stiffening" bar from a steel angle that can put more pressure on the valve cover . say a steel angle that has holes for all the 4 c/l bolts and can be arranged to put pressure on the ends of the valve cover. :thumb:


Good idea. I am a bit nervous about overtightening the nuts on top of the cover for fear of warping or causing some other damage that could make the problem worse. With this I could torque down a bit without risk of damage to the cover.

skipmac 18-09-2019 14:18

Re: Oil leak from valve cover
 
Quote:

Originally Posted by sailormed (Post 2979516)
My favorite gasket goop in this case is Hylomar Universal Blue.


Well I'm not where I can access specialty goops. Guess I could order it from Amazon but I want instant gratification. Think the Permatex blue would substitute?

rbk 18-09-2019 14:28

Re: Oil leak from valve cover
 
Quote:

Originally Posted by skipmac (Post 2979528)
Good idea. I am a bit nervous about overtightening the nuts on top of the cover for fear of warping or causing some other damage that could make the problem worse. With this I could torque down a bit without risk of damage to the cover.

The cover can take a fair bit of pressure. And you really end up compressing the inserts more than you'd think. The only real issue with the above is the cover should 'float' on the gasket and the inserts, this could transfer a lot of vibration to the cover and eventually lead to cracking. Maybe the stiffening plate and a chunk of cork under to reduce vibration?

skipmac 18-09-2019 14:39

Re: Oil leak from valve cover
 
Quote:

Originally Posted by rbk (Post 2979537)
The cover can take a fair bit of pressure. And you really end up compressing the inserts more than you'd think. The only real issue with the above is the cover should 'float' on the gasket and the inserts, this could transfer a lot of vibration to the cover and eventually lead to cracking. Maybe the stiffening plate and a chunk of cork under to reduce vibration?


I'm wondering if the pro I hired to do this just didn't torque the cover down enough. Rough guess on what's appropriate?

model 10 18-09-2019 14:47

Re: Oil leak from valve cover
 
Valve cover gaskets are done a little different. You glue the gasket to the cover so it won't leak. Then use nothing between the gasket and the head surface. This allows you to remove the cover and still use the gasket again. You could use some non setting gasket dressing on that side if you wanted.

a64pilot 18-09-2019 14:49

Oil leak from valve cover
 
OK, letís start from the beginning, most of the time if a sheet metal valve cover leaks, itís because itís been overtightned, what happens is the area around the holes distorts a little, the hole gets bent inward, what you do to fix this, and is a good idea to do anyway, is to take a ball peen hammer and with the pan held upside down and the edge of it on a table ledge, place the peen end of the hammer in the hole the stud goes through and hit it with another hammer, hit it pretty hard.
This bends the cover back to straight, or actually a little bend opposite does no harm, just a little though.
If the cover leaks after a new gasket I can almost guarantee itís distorted, further tightening usually almost always is not the answer it usually makes the leak worse, and if it gets worse with tightening itís almost guaranteed itís a distorted pan, distorted pans are very, very common and very easy to fix.
What is happening is the gasket is not tight against the head between the studs.
Hot rodders used to use cast valve covers because they donít distort, or bend, but if you get stupid they will break.
You only want to tighten the nuts as if they were screws, use a nut driver, that will keep you from overtorqueing, almost always the problem is over tightened, not being too loose.

Goop is never the answer, especially silicone, hydrocarbons, oil or gas or diesel will attack the silicone and break it down and youíll have what looks and feels like slimly bass worms.

Way back in the day people used to use contact cement and glue the gasket to the valve cover, this works fine, but you really need a wire brush in a grinder to clean off the glue, but if you have a wire brush in a grinder you can clean a cover up in short time and the gasket surface looks new.

But never, ever put any kind of sealer between the gasket and the head unless you want a mess and it screams this guy doesnít know what heís doing.
You wouldnít use a granny knot to attach your sheets to the jib would you? Then why would you use goop on a valve cover gasket?

If you ever pull an oil pan, donít even consider reinstalling it without Peening the holes, itís cheap Insurence.

Personally I wonít glue any gasket, paper ones like water pumps for instance or timing chain covers Iíll use grease to hold it in place, but if you glue one, it can be hell to clean off the next time.

Good valve cover gaskets will last many removals, we used to run roller rocker arms on drag cars and were pulling the covers all the time to adjust valves, there is no pressure so itís not hard for a valve cover gasket to seal, as long as there is a flat surface.

Wotname 18-09-2019 15:11

Re: Oil leak from valve cover
 
A64Pilot makes some points points however I have found it difficult to restore the integrity of the trueness of the cover when it only uses centre line bolts.

The leak has been persistent in the past which suggests to me the cover is distorted when tightened down. So it isn't just a gasket or torque issue any more.

I know you have checked the cover for trueness but that was only done off the engine. I think the cover is designed to have a certain degree of spring to compress the gasket when correctly tightened but if it has over torqued in the past, that spring has been compromised. Put another way, the cover is no longer true when tightened.

How to fix? I used the following method sort of successfully for the rocker covers on old Morris A series engines - the same design vintage as a Perkins I believe.

Use some flexible "form a thick gasket" product (experiment with what is available in your area).
Apply thickly to the cover lip.
Allow to set a bit with cover upside down.
Fit proper gasket on top of the product.
Turn the whole cover right side up and place on a very flat surface.
Add some weights to the top of the cover around where the centreline bolts are. Again some experimentation is needed to get the right weight.
Allow the product to cure.
Then fit to engine and torque gently.

There are likely to better and more professional ways but my DIY method has worked for me.

skipmac 18-09-2019 15:19

Re: Oil leak from valve cover
 
Quote:

Originally Posted by Ecos (Post 2979548)
Valve cover gaskets are done a little different. You glue the gasket to the cover so it won't leak. Then use nothing between the gasket and the head surface. This allows you to remove the cover and still use the gasket again. You could use some non setting gasket dressing on that side if you wanted.




:thumb:

rbk 18-09-2019 15:41

Re: Oil leak from valve cover
 
Quote:

Originally Posted by a64pilot (Post 2979550)
OK, letís start from the beginning, most of the time if a sheet metal valve cover leaks, itís because itís been overtightned, what happens is the area around the holes distorts a little, the hole gets bent inward, what you do to fix this, and is a good idea to do anyway, is to take a ball peen hammer and with the pan held upside down and the edge of it on a table ledge, place the peen end of the hammer in the hole the stud goes through and hit it with another hammer, hit it pretty hard.
This bends the cover back to straight, or actually a little bend opposite does no harm, just a little though.
If the cover leaks after a new gasket I can almost guarantee itís distorted, further tightening usually almost always is not the answer it usually makes the leak worse, and if it gets worse with tightening itís almost guaranteed itís a distorted pan, distorted pans are very, very common and very easy to fix.
What is happening is the gasket is not tight against the head between the studs.
Hot rodders used to use cast valve covers because they donít distort, or bend, but if you get stupid they will break.
You only want to tighten the nuts as if they were screws, use a nut driver, that will keep you from overtorqueing, almost always the problem is over tightened, not being too loose.

Goop is never the answer, especially silicone, hydrocarbons, oil or gas or diesel will attack the silicone and break it down and youíll have what looks and feels like slimly bass worms.

Way back in the day people used to use contact cement and glue the gasket to the valve cover, this works fine, but you really need a wire brush in a grinder to clean off the glue, but if you have a wire brush in a grinder you can clean a cover up in short time and the gasket surface looks new.

But never, ever put any kind of sealer between the gasket and the head unless you want a mess and it screams this guy doesnít know what heís doing.
You wouldnít use a granny knot to attach your sheets to the jib would you? Then why would you use goop on a valve cover gasket?

If you ever pull an oil pan, donít even consider reinstalling it without Peening the holes, itís cheap Insurence.

Personally I wonít glue any gasket, paper ones like water pumps for instance or timing chain covers Iíll use grease to hold it in place, but if you glue one, it can be hell to clean off the next time.

Good valve cover gaskets will last many removals, we used to run roller rocker arms on drag cars and were pulling the covers all the time to adjust valves, there is no pressure so itís not hard for a valve cover gasket to seal, as long as there is a flat surface.

This could be as well. The Perkins has a second lip at the bottom of the cover to make it more rigid. This could also be impeding the seal if an improper gasket was used as it can limit the depth to which the cover can be torqued and is essentially bottoming out with a gasket thats too thin,which may be why the mechanic gooped it up? Other possibility is the mechanic actually read the permatex instructions and half torqued the cover then was letting it set up before final torque which never got completed?

skipmac 18-09-2019 16:23

Re: Oil leak from valve cover
 
I was hoping you would chime in on this. Thanks.


Reading your suggestion about peening the holes in the cover are you talking about a cover that has the holes around the circumference on the lip of the cover? This cover has four holes that run longitudinally down the center of the top of the cover that fit over studs coming up between the rocker arms on the head.



Regarding the mechanic over tightening the bolts, when I removed them they were not extremely tight. I did have a socket wrench but could have easily removed them with a nut driver.


Regardless, even though it looks pretty flat checking with a straight edge I'm wondering if there is enough distortion or as you mention, loss in the spring, to cause the leak.



Quote:

Originally Posted by a64pilot (Post 2979550)
OK, letís start from the beginning, most of the time if a sheet metal valve cover leaks, itís because itís been overtightned, what happens is the area around the holes distorts a little, the hole gets bent inward, what you do to fix this, and is a good idea to do anyway, is to take a ball peen hammer and with the pan held upside down and the edge of it on a table ledge, place the peen end of the hammer in the hole the stud goes through and hit it with another hammer, hit it pretty hard.
This bends the cover back to straight, or actually a little bend opposite does no harm, just a little though.
If the cover leaks after a new gasket I can almost guarantee itís distorted, further tightening usually almost always is not the answer it usually makes the leak worse, and if it gets worse with tightening itís almost guaranteed itís a distorted pan, distorted pans are very, very common and very easy to fix.
What is happening is the gasket is not tight against the head between the studs.
Hot rodders used to use cast valve covers because they donít distort, or bend, but if you get stupid they will break.
You only want to tighten the nuts as if they were screws, use a nut driver, that will keep you from overtorqueing, almost always the problem is over tightened, not being too loose.

Goop is never the answer, especially silicone, hydrocarbons, oil or gas or diesel will attack the silicone and break it down and youíll have what looks and feels like slimly bass worms.

Way back in the day people used to use contact cement and glue the gasket to the valve cover, this works fine, but you really need a wire brush in a grinder to clean off the glue, but if you have a wire brush in a grinder you can clean a cover up in short time and the gasket surface looks new.

But never, ever put any kind of sealer between the gasket and the head unless you want a mess and it screams this guy doesnít know what heís doing.
You wouldnít use a granny knot to attach your sheets to the jib would you? Then why would you use goop on a valve cover gasket?

If you ever pull an oil pan, donít even consider reinstalling it without Peening the holes, itís cheap Insurence.

Personally I wonít glue any gasket, paper ones like water pumps for instance or timing chain covers Iíll use grease to hold it in place, but if you glue one, it can be hell to clean off the next time.

Good valve cover gaskets will last many removals, we used to run roller rocker arms on drag cars and were pulling the covers all the time to adjust valves, there is no pressure so itís not hard for a valve cover gasket to seal, as long as there is a flat surface.


Compass790 18-09-2019 16:37

Re: Oil leak from valve cover
 
Another good trick I use is to make up an o-ring say 3 mm thick. You can buy bulk 0-ring in any length you want cut & glue it using super glue or if you are fussy buy o-ring glue
Glue the o-ring to the rocker cover & voila a reusable gasket.

skipmac 18-09-2019 19:21

Re: Oil leak from valve cover
 
1 Attachment(s)
Here's a photo of the valve cover. The downhill, leaking side is to the left.


While it is stamped sheet metal it is reasonably substantial and as rbk mentioned the lip around the edge has a double bend to add stiffness. That however doesn't necessarily mean it hasn't warped a little.

Compass790 18-09-2019 19:34

Re: Oil leak from valve cover
 
Quote:

Originally Posted by Wotname (Post 2979574)
A64Pilot makes some points points however I have found it difficult to restore the integrity of the trueness of the cover when it only uses centre line bolts.

The leak has been persistent in the past which suggests to me the cover is distorted when tightened down. So it isn't just a gasket or torque issue any more.

I know you have checked the cover for trueness but that was only done off the engine. I think the cover is designed to have a certain degree of spring to compress the gasket when correctly tightened but if it has over torqued in the past, that spring has been compromised. Put another way, the cover is no longer true when tightened.

How to fix? I used the following method sort of successfully for the rocker covers on old Morris A series engines - the same design vintage as a Perkins I believe.

Use some flexible "form a thick gasket" product (experiment with what is available in your area).
Apply thickly to the cover lip.
Allow to set a bit with cover upside down.
Fit proper gasket on top of the product.
Turn the whole cover right side up and place on a very flat surface.
Add some weights to the top of the cover around where the centreline bolts are. Again some experimentation is needed to get the right weight.
Allow the product to cure.
Then fit to engine and torque gently.

There are likely to better and more professional ways but my DIY method has worked for me.

Sounds like a great plan to me Wotname:thumb:

skipmac 18-09-2019 19:43

Re: Oil leak from valve cover
 
Quote:

Originally Posted by Wotname (Post 2979574)
A64Pilot makes some points points however I have found it difficult to restore the integrity of the trueness of the cover when it only uses centre line bolts.

The leak has been persistent in the past which suggests to me the cover is distorted when tightened down. So it isn't just a gasket or torque issue any more.

I know you have checked the cover for trueness but that was only done off the engine. I think the cover is designed to have a certain degree of spring to compress the gasket when correctly tightened but if it has over torqued in the past, that spring has been compromised. Put another way, the cover is no longer true when tightened.

How to fix? I used the following method sort of successfully for the rocker covers on old Morris A series engines - the same design vintage as a Perkins I believe.

Use some flexible "form a thick gasket" product (experiment with what is available in your area).
Apply thickly to the cover lip.
Allow to set a bit with cover upside down.
Fit proper gasket on top of the product.
Turn the whole cover right side up and place on a very flat surface.
Add some weights to the top of the cover around where the centreline bolts are. Again some experimentation is needed to get the right weight.
Allow the product to cure.
Then fit to engine and torque gently.

There are likely to better and more professional ways but my DIY method has worked for me.


This may work although I'm thinking about a modified version of this idea. As mentioned, the engine is mounted on an angle which results in some oil pooling at the lower end of the head when the engine is pumping oil and this I'm almost positive is where it's leaking. So my thought is to focus on that end of the cover which might be easier and work better than trying to get an even seal all the way around. So build up some formagasket (yes I have some in the spares) just around that end of the cover, carefully tapering it away.


Idea #2 is to try some thicker, flexible o-ring material like suggested by compass790.


Idea #3, try to bend the end of the cover down a bit so it seals better against the gasket. I am very reluctant to try this as there could be a rist of damaging the cover and a replacement would be difficult to impossible to find.



Any other ideas? Any votes on which solution sounds best?

model 10 18-09-2019 20:01

Re: Oil leak from valve cover
 
Plan B. The head surface is probably true. The bottom surface of the gasket is also true.You are never going to get the valve cover surfact true, so fill the space between the gasket and the valve cover with glue and assemble. Tighten tomorrow.

Compass790 18-09-2019 20:16

Re: Oil leak from valve cover
 
Have you checked rocker cover against a flat surface?
If you follow Wotnames plan it self corrects for the warpage IF you have access to a flat surface. As Ecos says yr cylinder head is likely flat.
I have found just silicone works well too & I think using Wotnames method & putting silicone between gasket & rocker cover then letting it go off somewhat would work well.
As I said before fattish o-rings work good too but if your warpage is extreme maybe Wotnames method would be better. If he can stop a Pommy engine from leaking oil ya have to give him kudos for that.
More than one way to skin a cat

Wotname 18-09-2019 22:52

Re: Oil leak from valve cover
 
Quote:

Originally Posted by Compass790 (Post 2979759)
......If he can stop a Pommy engine from leaking oil ya have to give him kudos for that.
.........

Well the OP's engine was probably manufactured in the UK, certainly it was designed in the UK so it should leak some oil. Absence of a minor oil leak is considered a defect (or a lack of oil) :biggrin:

skipperpete 18-09-2019 23:59

Re: Oil leak from valve cover
 
There is a vague possibility that you have some rust pinholes through that valve cover and not a leaking gasket. The photo shows the area near the Lhs bolt hole is corroded and it looks like there might be another area of rust near and just above the sealing edge on the left.

skipmac 19-09-2019 03:32

Re: Oil leak from valve cover
 
Quote:

Originally Posted by Wotname (Post 2979819)
Well the OP's engine was probably manufactured in the UK, certainly it was designed in the UK so it should leak some oil. Absence of a minor oil leak is considered a defect (or a lack of oil) :biggrin:


I always assumed it was the British way to maximize the time between oil changes. Just keep pumping new oil in and out of the engine on a continual basis.


This reminds me of my theory of repairing some unknown, complicated piece of kit. If I don't have at least one screw or small part of some kind left on the bench after it's reassembled I must have done something wrong. :rolleyes:

skipmac 19-09-2019 03:37

Re: Oil leak from valve cover
 
Quote:

Originally Posted by skipperpete (Post 2979837)
There is a vague possibility that you have some rust pinholes through that valve cover and not a leaking gasket. The photo shows the area near the Lhs bolt hole is corroded and it looks like there might be another area of rust near and just above the sealing edge on the left.


This is a possibility and will go look at that now. The PO did have a small, ongoing leak onto the rear of the engine from the anti-siphon valve which is one reason the cover looks so nasty.



In fact the whole engine looks like carp but it runs like a top, has perfect oil pressure, starts instantly and doesn't smoke at all so I hate to replace it. Then I run into a persnickety little problem like this and consider turning it into a mooring.

skipmac 19-09-2019 03:45

Re: Oil leak from valve cover
 
After reading all the suggestions and sleeping on it (for a while I was not sleeping on it) I think I have a plan.


First I'll try and easy fix and see if I get lucky. Have cleaned the cover and gasket and will reinstall as is but with a modified tightening plan. I will snug down the nut on the leaky end firmly but the next one in line just more than finger tight. The next two I think maybe in between in how much I tighten them.



If that doesn't work I will try some method of increasing the contact pressure on the leaky end. Using a gasket making goop is one idea but I thought about building up the sealing area on rim of the cover with MarineTex or JB Weld. That has the advantage of being able to easily shape by sanding and filing but could still be sanded completely off if it didn't work or makes things worse.


Thoughts?

Compass790 19-09-2019 03:48

Re: Oil leak from valve cover
 
Quote:

Originally Posted by skipmac (Post 2979904)
This is a possibility and will go look at that now. The PO did have a small, ongoing leak onto the rear of the engine from the anti-siphon valve which is one reason the cover looks so nasty.



In fact the whole engine looks like carp but it runs like a top, has perfect oil pressure, starts instantly and doesn't smoke at all so I hate to replace it. Then I run into a persnickety little problem like this and consider turning it into a mooring.

Hell no! If it runs as good as you say just work on the problem at hand.Trust me, you'll figure it out in the end with the help of the hive. The problem is with the modern engines is they make it more & more difficult to repair yourself. Then they make sure they last for much less time.
Makes for more employment ( tho mostly for 'Bots these days ) & maximises the CEO's bonus. Funny that
Better to use sails where possible IMHO:smile:

skipmac 19-09-2019 04:04

Re: Oil leak from valve cover
 
Quote:

Originally Posted by Compass790 (Post 2979907)
Hell no! If it runs as good as you say just work on the problem at hand.Trust me, you'll figure it out in the end with the help of the hive. The problem is with the modern engines is they make it more & more difficult to repair yourself. Then they make sure they last for much less time.
Makes for more employment ( tho mostly for 'Bots these days ) & maximises the CEO's bonus. Funny that
Better to use sails where possible IMHO:smile:


Oh I am resisting the impulse but occasionally the frustration builds. I did strip the engine down and replaced everything external: alternator, both water pumps, all hoses and belts, most of the accessory brackets, all coolers (oil, transmission and main heat exchanger), wiring. So hopefully this will be the last of the big/little problems.


And yes I sail it. I learned to sail when I was too broke to buy diesel and sailed everywhere, all the time. The only exception was in and out of slips which most marinas don't allow. Last year I ran the engine less than 50 hours and most of that was three days motoring up the US ICW when it was a bit stormy and I decided to go inside to avoid rounding Cape Hatteras in a blow.


Bottom line, I think I'm smarter than a 35 year old piece of British iron but we shall see.

skipperpete 19-09-2019 04:39

Re: Oil leak from valve cover
 
Quote:

Originally Posted by skipmac (Post 2979911)
Oh I am resisting the impulse but occasionally the frustration builds. I did strip the engine down and replaced everything external: alternator, both water pumps, all hoses and belts, most of the accessory brackets, all coolers (oil, transmission and main heat exchanger), wiring. So hopefully this will be the last of the big/little problems.


And yes I sail it. I learned to sail when I was too broke to buy diesel and sailed everywhere, all the time. The only exception was in and out of slips which most marinas don't allow. Last year I ran the engine less than 50 hours and most of that was three days motoring up the US ICW when it was a bit stormy and I decided to go inside to avoid rounding Cape Hatteras in a blow.


Bottom line, I think I'm smarter than a 35 year old piece of British iron but we shall see.



Provided the oil pressure is good and it has no bad noises or blow by just keep it. Incidentally your 4-154 later became a Mazda XA and was one of the best Perkins models produced.

skipmac 19-09-2019 04:55

Re: Oil leak from valve cover
 
Quote:

Originally Posted by skipperpete (Post 2979932)
Provided the oil pressure is good and it has no bad noises or blow by just keep it. Incidentally your 4-154 later became a Mazda XA and was one of the best Perkins models produced.


Yes forgot to mention that one, oil pressure good and no blowby or weird sounds. Also forgot to say I have a new starter as well.


Glad to hear it has such a good reputation. Makes me feel better about all the effort I put into keeping it.

a64pilot 19-09-2019 05:39

Re: Oil leak from valve cover
 
I was speaking about a cover that has the holes in the perimeter.
They few ones that I have had leaks on with center line bolts, ended up having old pieces of glue or even a piece of gasket under the new one that held the new one ďproudĒ of the surface.
Very often the center line bolted covers do use the better black rubber gaskets as opposed to the cork and rubber mixed ones,that do work, just not as good as the black rubber.
Of you can find a mechanic shop around that has a bench grinder with a wire wheel to clean gaskets off I heavily recommend asking them to clean the cover or let you.
I donít care of you spend a week scraping you canít get one as clean as that grinder with a wire brush can in a minute.
Unlikely itís warped, theses covers are usually pretty strong, but check, see if the edges are bent up,if they are an adjustable wrench can be used or gently bend the edges back down.
You are smarter than a 35 yr old piece of iron.
However I think on especially some older Brit designs that oil weeps were acceptable and an absolute clean engine may be tough.
I had my old MG leak free, but you really had to pay attention on reassembly to get there.

skipmac 19-09-2019 07:02

Re: Oil leak from valve cover
 
Quote:

Originally Posted by a64pilot (Post 2979958)
I was speaking about a cover that has the holes in the perimeter.
They few ones that I have had leaks on with center line bolts, ended up having old pieces of glue or even a piece of gasket under the new one that held the new one ďproudĒ of the surface.
Very often the center line bolted covers do use the better black rubber gaskets as opposed to the cork and rubber mixed ones,that do work, just not as good as the black rubber.
Of you can find a mechanic shop around that has a bench grinder with a wire wheel to clean gaskets off I heavily recommend asking them to clean the cover or let you.
I donít care of you spend a week scraping you canít get one as clean as that grinder with a wire brush can in a minute.
Unlikely itís warped, theses covers are usually pretty strong, but check, see if the edges are bent up,if they are an adjustable wrench can be used or gently bend the edges back down.
You are smarter than a 35 yr old piece of iron.
However I think on especially some older Brit designs that oil weeps were acceptable and an absolute clean engine may be tough.
I had my old MG leak free, but you really had to pay attention on reassembly to get there.


Well the more I think about it the more certain I am that I'm smarter than the engine. However, it can be difficult for smart to overcome stubborn and these old diesels can be quite stubborn.



I have closely inspected the cover and cleaned it carefully and the mounting flange is perfectly clean and was actually very clean with no visible chunks on it when I took it off. Also got a bright light in a dark room and verified no pinholes. So eliminated two possible sources of the problem, I think.


So what do you (or anyone else in the group) think about my plans A and B.


A. Selective tightening of the retainer nuts on the cover to minimize the chance of warping the end.


B. Building up the leaky end of the cover to make the gasket a little more proud on that end to enhance the seal.


Or any suggestions for a plan C or a better plan A?

rbk 19-09-2019 08:17

Re: Oil leak from valve cover
 
Start with tightening then tighten again and if that fails try and build it up. The built up gasket may leak more as they tend to leak out the joints as youíre adding more layers/joints and if high enough they may rock or distort under pressure. If doing this, start with brand new gaskets, laminate them on a bench with a nice even layer of rtv or similar, clean up the joints and let fully cure before installing.

skipmac 19-09-2019 09:46

Re: Oil leak from valve cover
 
Will definitely try careful tightening of the cover before going crazy with other stuff.



But a question. To avoid running the engine and looking for oil to pour out into my bilge (again and I'm starting to run low on oil absorbent towels) I'm wondering if sticking a feeler gauge into the joint would be test enough to determine if the leak is fixed or at least decreased.

bongo 19-09-2019 10:22

Re: Oil leak from valve cover
 
As a marine engineer with over decades of engine room experience, I agree with others here that clean and square and snug are all important. What I want to add is that many gaskets have no fiber reinforcement. If it does not have this reinforcement, then using any sort of goop allows the gasket to deform, (extrude), from its designed dimensions, and they usually leak. If you need to set the gasket in place on the valve cover, apply a very thin layer of the proper silicon, (or contact cement, or Permatex #2), to the clean, dry surface on the valve cover, set the gasket carefully in place, and let it set overnight. After it has set it will not push out when tightening the cover to the cylinder head. make sure the mating surface on the head is absolutely clean and dry with no oily film. Denatured alcohol works good here. Worked great on my Westerbeke 40/Perkins 4-108.

Now I've got to figure out how to get to the rear engine crankshaft seal?

skipmac 19-09-2019 10:36

Re: Oil leak from valve cover
 
Quote:

Originally Posted by bongo (Post 2980144)
As a marine engineer with over decades of engine room experience, I agree with others here that clean and square and snug are all important. What I want to add is that many gaskets have no fiber reinforcement. If it does not have this reinforcement, then using any sort of goop allows the gasket to deform, (extrude), from its designed dimensions, and they usually leak. If you need to set the gasket in place on the valve cover, apply a very thin layer of the proper silicon, (or contact cement, or Permatex #2), to the clean, dry surface on the valve cover, set the gasket carefully in place, and let it set overnight. After it has set it will not push out when tightening the cover to the cylinder head. make sure the mating surface on the head is absolutely clean and dry with no oily film. Denatured alcohol works good here. Worked great on my Westerbeke 40/Perkins 4-108.

Now I've got to figure out how to get to the rear engine crankshaft seal?


Thanks bongo. I had earlier checked the gasket and thought it was nitrile or some kind of rubber but this morning in bright light I see it looks like a rubber impregnated cork or some similar material. The cork (or whatever) is in very fine particles with no visible texture and the overall gasket is flexible like rubber but firm so would not extrude under pressure.


Head surface is very clean and in good condition but have not wiped it with any kind of solvent or degreaser to remove the fine oil film.


So based on this info what's your suggestion?

Cadence 19-09-2019 11:24

Re: Oil leak from valve cover
 
Just maybe a stupid suggestion. Be sure the four bolts a tightened about the same.


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