jpc647

It appears after replacing the Valve Cover Gaskets on the drivers side of my 72 Cutlass with a 350, the back lower bolt, next to the brake booster is leaking oil, an quite a bit. I can see the oil squeeze out through the bolt and the cover, slide down the cover and drip onto the starter.

I've removed the bolt, tried sealing it with Silicone to no avail. I then tried sealing it with Permatex Gasket Sealant to no avail. Factory bolts, factory heads, aftermarket M/T Covers. I'm at a loss for words.

I've tried switching bolts too, to no avail. Something so easy, which should have taken an hour, has been a two day project.

Lady72nRob71

Sounds like the gasket is not sealing correctly around that bolt. Might need to pop the valve cover off and check for warped cover or debris between the mating surfaces and the gasket. What gasket are you using?
I use the brack rubber ones and they seal perfectly without sealers.

MDchanic

Clean thoroughly and use LOTS of black RTV, then quickly and carefully clean up all the overflow as you tighten it, and you should be good.

You'll need a prybar and a sledgehammer to remove them, but they won't leak.

- Eric

ah64pilot

What gasket did you use? The best gasket is the fel-pro 11/64" rubber gasket. Put High-Tack on the valve cover side to glue it to the cover, then leave the block side dry. Torque down starting in the middle and working your way outwards, remember they only take 7-10 ft. lbs. I use a cordless drill with it set to an impact setting of 5 - 7. Then just snug them up by hand on the last run.

jpc647

This is exaclty what I did. I used the thicker 11/64 gaskets too. They sell a 3/32 as well. I used High Tack on the gasket, matted it to the cover, let it sit for a couple of minutes, then put it on. It leaked, so I took it off, and tried Permatex on the block side, and it still leaks.

So I tried sealing just that bolt, to no avail. I guess I'm off to buy another set of covers to try again. I Permatex'd the bolt again last night, and am let it sit over night, just to see. Maybe I ran it too quickly before the permatex had a change to set up. We'll see this afternoon, but I'll be buying new gaskets on the way home, regardless.

Lady72nRob71

Make sure your cover is not warped around that bolt hole. It happens when it is overtightened.

oldcutlass

Did you make sure all your drain reaturns were clear at both ends of your heads? I use 3M yellow weatherstrip cement on my valvecovers. First I degease the valvecovers with brakeclean, and then I apply a very light coat to the valvecover, and a very light coat to the gasket. Let them both sit apart until they skin over (about 5 mins) and then stick the gasket to the valvecover.

jpc647

How does one do that? With a hammer and dolly?

I was asking my dad about the drain returns too. Maybe a small piece of the old gasket is stuck in there and causing the oil to pool up too much. When I remove the valve cover again I'll check. Can I blow them out with air from a compressor? Or is that a bad idea?

ah64pilot

Can I ask how old these covers are and where you got them from? I have a suspicion...

Lady72nRob71

Something like that - as long as the mating surface is flat. A slight warp is okay but not extreme. How does that hole compare to the rest of the holes?

Bad idea - you will blow crap INTO the engine and oily grunge all over.
Scrape out any gunk with a flat medium screwdriver.
This thread applies to most Olds heads and has lots of good info...
https://classicoldsmobile.com/forums...tml#post294407

jpc647

I bought the car with these covers on them. They were fine for 3 years, no leaks. I had to take the covers off to install a larger metal baffle under the PCV valve, because oil was splashing up. At that point I tried reinstalling the old gaskets and covers, they seemed fine, but started weeping. I bought new gaskets last week, tried to install them on the same covers and have been having problems since. I thought maybe when I first installed the gaskets, I over tightened the bolts, squishing the gasket too much( I actually crushed the gasket).


This is the only hole that leaks, the others don't. When I take the covers off tonight/tomorrow I'll post pictures of it. Thanks for the information thread as well.

droptopron

Inspect them carefuly for a crack

ah64pilot

The reason I ask is because I was thinking maybe they were bad castings...but if they were on before they're probably ok.

Is it possible you dropped one and cracked it? Or did you really pinch the gasket?

jpc647

Thats my thinking. I'll be removing them tonight.

I never dropped one of them. I really pinched the gasket. I tightened them down hard enough that when I took them off and looked at the gasket, the semi circle where the bolt goes through, was almost entirely seperated from the part that sits in the valley of the cover. I'll post a picture tonight.

jpc647

Not the greatest picture, but you can see that it is leaking from between the bolt and the over, after a ton of permatex. When I took the bolt out, the threads were completely clean, no permatex on them!? I don't understand.The car is hott right now, but I'll be taking the ocvers off in a few to look inside, again.

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The new gasket, after tightened it down too tight. Now ever since, the bolt hole has been leaking. The threads seem fine, I've put different bolts in.
20120908_101513.jpg

Now it's time to check the cover, and see if there is a problem. What else could it be? Where did all the permatex go!?

jpc647

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The drains holes don't appear to be blocked. The motor looks pretty clean, right? Is oil supposed to puddle up like it is in the first picture? I don't want to reinstall the covers, and waste another set, until I figure out what the problem is.

Lady72nRob71

Oil returns look great. A slight puddle is fine. The issue must be with the cover and gasket.
First, get some new felpro thick rubber gaskets.

Next get a razor blade and carefully scrape off all the residue from the head mating surfaces. After only metal appears, clean it and lightly wipe with clean oil.

Next scrape off the residue from the cover mating surfaces. Check the cover hole areas for flatness, repair if needed. It does not need to be perfect - just get the worst of the bends out.

Apply just a little sealer onto the cover around the bolt holes, just enough to tack the gasket to the cover to ease installation. Not too much!
Put a light coat of clean oul on the engine side of the gasket, much like an oil filter.

Put the cover on and finger tighten the screws.
Next, with only a nutdriver, start snugging them little by little and go in a clockwise pattern. It might take 10 times around, but its okay. Do not over tighten, as that warps the cover and causes leaks. Tightest should be "snug" with only a nutdriver.
Forget the torque wrench set to 7lbs - that was for the factory gasket material, not this rubber stuff.

I did it just like this last year and after 800 miles, not a weep.

BTW, what was your last picture of?

jpc647

Rob,

That's almost exactly what I did the first time and the second, except I used a sharp putty knife instead of a razor. They were out of rubber gaskets, so i'm going to use the cork ones this time.

My last picture was a top down show of the outside of the cover looking at the bolt hole. (They are M/T Covers). I might try a little JB weld around the bolt hole and let it set. Maybe there is a small pin-hole or something in the cover and the oil is weeping through. I can't see it, but maybe it's there. I'll make it smooth as glass when it's wet, and let it set up for a day or so, just to see.

Octania

I will respectfully DISAGREE with the above recommendation. I have autopsied engines which died of silicone overdose. More is NOT better. The silicone will get squeezed out [inside the motor also] and later these strings can break off and go clog the oil pump inlet. Or worse yet get thru the inlet screen bypass. I have found them in the oil FILTER bypass. Guess what the next stop is? Your bearings.

Always use JUST ENOUGH silicone to create a thin layer- except when filling a gap such as at the intake end rails.

Me, I use and recommend Permatex 3H Aviation gasket sealer for this application. There are LOTS of other gasket goos besides silicone. Those set forth above by others are also very suitable...

Your gasket is imperfect. Replace it, use a proper amount of the proper spooge. Secure the bolts as set forth above, round and round a little at a time, until the same small amt of torque results in little or no additional screw turning. You may find a universal socket handy for tight quarters.

This has worked well for me for years.

MDchanic

I understand your point. I suppose it didn't occur to me that someone might interpret what I wrote as recommending an excessive amount of goo on the inside of the engine.

I would never use so much that it would drip, but in a case like this, where you have a mystery leak, I would use enough to get a small but meaningful bead of ooze.

As I implied by my sledgehammer comment, this is not the "right" way, but sometimes, when parts just don't fit right, it's the effective way.

I will use caution with words like "lots" in the future.

- Eric