Cruisers Forum
 


Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 18-09-2019, 15:19   #16
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
Re: Oil leak from valve cover

Quote:
Originally Posted by Ecos View Post
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.



__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 18-09-2019, 15:41   #17
rbk
Registered User
 
rbk's Avatar

Join Date: Feb 2016
Location: Canada
Boat: T37
Posts: 2,095
Re: Oil leak from valve cover

Quote:
Originally Posted by a64pilot View Post
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?
rbk is offline   Reply With Quote
Old 18-09-2019, 16:23   #18
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
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 View Post
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.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 18-09-2019, 16:37   #19
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,416
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.
Compass790 is offline   Reply With Quote
Old 18-09-2019, 19:21   #20
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
Re: Oil leak from valve cover

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.
Attached Thumbnails
Click image for larger version

Name:	20190918_220800.jpg
Views:	66
Size:	401.1 KB
ID:	200108  
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 18-09-2019, 19:34   #21
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,416
Re: Oil leak from valve cover

Quote:
Originally Posted by Wotname View Post
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
Compass790 is offline   Reply With Quote
Old 18-09-2019, 19:43   #22
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
Re: Oil leak from valve cover

Quote:
Originally Posted by Wotname View Post
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?
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 18-09-2019, 20:01   #23
Registered User

Join Date: Feb 2013
Location: Oregon
Boat: Seafarer36c
Posts: 5,565
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.
model 10 is offline   Reply With Quote
Old 18-09-2019, 20:16   #24
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,416
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
Compass790 is offline   Reply With Quote
Old 18-09-2019, 22:52   #25
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 12,792
Re: Oil leak from valve cover

Quote:
Originally Posted by Compass790 View Post
......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)
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Old 18-09-2019, 23:59   #26
Registered User

Join Date: Feb 2010
Location: Australia
Posts: 832
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.
skipperpete is offline   Reply With Quote
Old 19-09-2019, 03:32   #27
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
Re: Oil leak from valve cover

Quote:
Originally Posted by Wotname View Post
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)

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.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 19-09-2019, 03:37   #28
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
Re: Oil leak from valve cover

Quote:
Originally Posted by skipperpete View Post
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.
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 19-09-2019, 03:45   #29
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29į 49.16í N 82į 25.82í W
Boat: Pearson 422
Posts: 15,490
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?
__________________
The water is always bluer on the other side of the ocean.
Sometimes it's necessary to state the obvious for the benefit of the oblivious.
Rust is the poor man's Loctite.
skipmac is offline   Reply With Quote
Old 19-09-2019, 03:48   #30
Marine Service Provider

Join Date: Sep 2014
Location: Auckland, NZ
Boat: Compass 790 , 7.9 metres or 26 ft
Posts: 2,416
Re: Oil leak from valve cover

Quote:
Originally Posted by skipmac View Post
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
Compass790 is offline   Reply With Quote
Reply

Tags
oil, oil leak

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Westerbeke w52 yellow tint in oil inside valve cover kevins Engines and Propulsion Systems 15 27-07-2018 13:35
Battery Terminal Cover or Cover Entire Battery Top ? sdowney717 Electrical: Batteries, Generators & Solar 5 14-07-2011 04:14

Advertise Here


All times are GMT -7. The time now is 02:37.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.