Oil leak from valve cover

[a64pilot]

Originally Posted by skipmac

Ah yes, the old rag behind the valve cover trick. Know it well.


Problem is, my leak got so big the rag wasn't working. If I could get the leak down to rag level quantities I would be a happy camper.

A turkey basting pan under the motor works well too.

There is a liquid gasket out that I have used that is very good now, I’ll look for it, but many modern engines apparently don’t have gaskets anymore, they just use this liquid stuff, saves $$$ I’m sure as the manufacturer doesn’t have to buy and stock gaskets anymore.
My Son’s Suzuki Samurai oil pan was like that, there are after market gaskets apparently, but if you use them, you have to replace all the bolts as with a gasket the stock bolts aren’t long enough.

Pretty sure it’s made by Permatex and called “The right stuff”.
I was surprised at how well it worked and I think that is what was used on my GM Duramax Diesel when I had its covers off to replace the injectors, and that motor is like a Yanmar, it doesn’t even seep oil, ever.

Anyway this Permatex stuff comes out of a can like cheese wiz.
Follow directions and it worked a treat.

I’d leave the gasket out and try it.
https://www.permatex.com/products/ga...asket-maker-3/

Click on the instruction tab.

I need to get some to carry and not worry about gaskets, don’t use for a carburetor gasket though

[skipmac]

Originally Posted by a64pilot

A turkey basting pan under the motor works well too.

There is a liquid gasket out that I have used that is very good now, I’ll look for it, but many modern engines apparently don’t have gaskets anymore, they just use this liquid stuff, saves $$$ I’m sure as the manufacturer doesn’t have to buy and stock gaskets anymore.
My Son’s Suzuki Samurai oil pan was like that, there are after market gaskets apparently, but if you use them, you have to replace all the bolts as with a gasket the stock bolts aren’t long enough.

Pretty sure it’s made by Permatex and called “The right stuff”.
I was surprised at how well it worked and I think that is what was used on my GM Duramax Diesel when I had its covers off to replace the injectors, and that motor is like a Yanmar, it doesn’t even seep oil, ever.

Anyway this Permatex stuff comes out of a can like cheese wiz.
Follow directions and it worked a treat.

I’d leave the gasket out and try it.
https://www.permatex.com/products/ga...asket-maker-3/

Click on the instruction tab.

I need to get some to carry and not worry about gaskets, don’t use for a carburetor gasket though

Well I'm already set up to give it one last go with what I have on hand. I cleaned the cover again but this time needed the wire wheel (small version to fit in my drill) to get the Permatex Red off. Then wiped it down, applied a generous bead and am letting the gasket set overnight. Tomorrow I'll wipe the mating surface on the head, apply a slightly less generous bead on the bottom of the gasket and screw it down again. If that doesnt' work then I'll main order some of the right stuff. I don't think anyone on the island stocks it.


So here's hopefully, one last question. There seems to be, literally, a dozen or more different flavors of Permatex. Reading their website I think they are recommending Permashield Dressing to seal between a gasket and mating surface but all I can find locally are various types of gasket making Permatex. I think the Red, hi temp gasket maker may be better at filling a gap than the dressing so am leaning towards that anyway.


Suggestions?

[model 10]

5200 Actually I'm not really kidding. Fill the cover with sealant and wax the mating surface. It will not leak and it will come right off again. This is how you can seal the cover plates on the bottom of aircraft fuel tanks.

[keith001]

I didn’t read all the advice so far but in case no one mentioned it, check that the oil return guides are clear. You need an air compressor and a rubber tip on the air hose. It’s been my problem before.

[skipmac]

Originally Posted by a64pilot

Anyway this Permatex stuff comes out of a can like cheese wiz.
Follow directions and it worked a treat.

I’d leave the gasket out and try it.
https://www.permatex.com/products/ga...asket-maker-3/

Click on the instruction tab.

I need to get some to carry and not worry about gaskets, don’t use for a carburetor gasket though

This stuff sounds really good. Going to order a couple of cans to keep on the boat and if the latest try doesn't work I'll have some on the way.

[skipmac]

Originally Posted by Ecos

5200 Actually I'm not really kidding. Fill the cover with sealant and wax the mating surface. It will not leak and it will come right off again. This is how you can seal the cover plates on the bottom of aircraft fuel tanks.

A thicker, stronger make it yourself gasket. How's it work for hi temp applications? I've used it for other applications where it wasn't supposed to work, like gluing a PVC rub rail back onto a Hypalon dinghy. Several years later still stuck tight but then it doesn't get a couple hundred degrees hot.

[skipmac]

Originally Posted by keith001

I didn’t read all the advice so far but in case no one mentioned it, check that the oil return guides are clear. You need an air compressor and a rubber tip on the air hose. It’s been my problem before.

Someone did and while I didn't check the drains specifically when I removed the cover a minute or so after running the engine for 15-20 minutes there was zero residual oil hanging out around the rockers.

[sailorboy1]

If I takes a bunch of “sealant” there’s a problem.

[model 10]

This isn't a Space shuttle O ring. You need as much sealant, as it takes to fill the lows. If you need a flat surface to check the valve cover, the galley counter or a grave stone are good. You assume the head will be flat.

[skipmac]

Originally Posted by sailorboy1

If I takes a bunch of “sealant” there’s a problem.

Of course there's a problem. Oil is pouring out from under my valve cover and making a big mess.

[Compass790]

Originally Posted by skipmac

Well I'm already set up to give it one last go with \

So here's hopefully, one last question. There seems to be, literally, a dozen or more different flavors of Permatex. Reading their website I think they are recommending Permashield Dressing to seal between a gasket and mating surface but all I can find locally are various types of gasket making Permatex. I think the Red, hi temp gasket maker may be better at filling a gap than the dressing so am leaning towards that anyway.


Suggestions?

Yes think you'll be fine with the red permatex. I've never used it I just use the cheapest RTV silicone frm builders supply places as they do the same job in our raw water cooled engine that would be lucky to reach 60oC on a hot day. Loctite 518 flange sealant is good too but quite expensive & you probly don't have it there
All the crankcase & gearbox joints are sealed with silicone in our engine & no gaskets but I just smear it on one face & let it go off before I bolted them up. Zero leaks but it's not British made so they aren't compulsory.
Allow its curing time before you start up if you are going to do the gasket face to head face with a wet joint. I'd tighten it maybe 1/2 tight when wet then do the final tighten after it's cured but whatever takes your fancy
Probly wont make much difference

[a64pilot]

Originally Posted by skipmac

Of course there's a problem. Oil is pouring out from under my valve cover and making a big mess.

I think his point is that it wasn’t pouring oil for decades without a bunch of sealant, now a bunch is required.
Why? What has changed? What’s different?
Maybe as someone posted it’s the oil drain back passages are clogged, and the oil used to drain back, but now fills up the area under the valve cover, and since there is now oil where oil didn’t used to be, it leaks?
I can see that happening, it’s logical and an easy thing to eliminate.

[skipmac]

Originally Posted by a64pilot

I think his point is that it wasn’t pouring oil for decades without a bunch of sealant, now a bunch is required.
Why? What has changed? What’s different?
Maybe as someone posted it’s the oil drain back passages are clogged, and the oil used to drain back, but now fills up the area under the valve cover, and since there is now oil where oil didn’t used to be, it leaks?
I can see that happening, it’s logical and an easy thing to eliminate.

Yea, I know but I have to give Sailorboy a little dig occasionally to keep him in line.


Seriously I do wonder what the heck is going on. It did leak a bit from the day I bought the boat but it seemed to be at a manageable level. It was about the same, still dripping and using oil absorbent towels last spring when I was getting ready to head north. So, as mentioned, while I was tied up with provisioning and other prep I paid a mechanic.



To be fair he does a good bit of engine work but mostly just minor parts swapping but I assumed putting on a new gasket would be well within his capabilities. Instead it got a lot worse and my first attempt at repair was no better. So either replacing a valve cover gasket is trickier than my admittedly amateur mechanics skills can handle or there is some underlying problem.

[waterman46]

Originally Posted by skipmac

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.

How can you use a feeler gauge in this case? The Perkins 4154 valve cover has a lip around the perimeter. That lip is maybe 2 or 3 mm high above (well, below, once cover is installed over valves) the sealing surface. Wouldn't that prevent insertion of a feeler gauge?

If you could insert a feeler gauge, that would indeed be a huge leak.
Did you try checking for a crack in the cover? Maybe plug the holes and fill with water. Or have you determined the exact location of the leak by careful monitoring while engine is running?

[AKA-None]

So we’re guessing there was no distortion of the cover which is a common issue from over tightening. Look around the bolt holes.