No matter what I do or use the valve cover leaks. The felpro versions leak bad, not as bad when you add gasket maker to them. The generic versions rubber ones I have found them to be best so far but still slow leak. Then I tried just factory style silicone rtv. Leaked like there was nothing at all.

I would like to hear you input how do I get these things to stop leaking?

I have original magnesium covers and original I iron heads. The problem lies in that the gasket or gasket material will not stick to the iron head. I have cleaned it thoroughly with brake cleaner but still no go with sealing properly.

Now ill gonna have to take the next two days getting the gasket maker off the valve covers to try again.

Help would be appreciated.

 

Hi
I have gone back to the standard cork type gasket on my 85 vette.
I also have had issues with the rubber type, unless your rocker cover's are 100% straight and level they won't seal without silicone sealant.

I have seen the damage silicone sealant can do to engines, all that gets loose will collect in the oil pickup screen
So i hate to use that stuff
The cork gaskets are quite good but they only last (seal) a few years
before they start to weep. Don't over-tighten the bolts !!!

 

So I should put sealant / gasket / sealant then apply the whole thing to the head? How tight should the bolt be just sung? I do not have a torque wrench.

Also I can't get the passenger side cover off anymore as much as I tug she doesn't budge. The block is a little warm think maybe when it cools down all the way it'll come off?

 

It helps to use the year in your post...saves time. I suggest Fel-Pro PERMADRY gaskets...ran them on my Iron head '86 for the last 5 years with no leaks....

 

It's an 1985 ... it's in my garage. I used the Felpro Permadry too, those leaked so bad that it was blowing bubbles when I started it, did yours have the rubber ridges on the top and bottom? Starting to think my valve covers may be too warped to use. They certainly aren't perfectly level but their not super bent either.

 

Check your head's gasket-mating surface and the valve-covers with a straight edge and a magnifying glass. Something's wrong if you're leaking that much.
Have you replaced the PVC valve lately?
Maybe you have a lot of blow-by from worn piston rings. (compression check)
Also, if you are putting the valve-covers on immediately after putting on the RTV, that's a mistake. You're supposed to let it set-up for about 10 min. before installing.

No intake leaks?

Hope you find the problem.

 

i only use the (original) factory RTV method. the key to this is you have to get both surfaces, valve cover and cylinder head, squeaky clean, and allow the RTV to cure. apply about 1/8" bead around the perimeter of the valve cover, set cover in place, torque to spec, AND WAIT 24 HOURS for the RTV to cure, then check or re-torque to spec. i've gone at least 10+ years or so on my 85 without any leaking. the problem most people have is they don't get both surfaces clean, they "squirt" the sealer on like they are caulking their basement windows, and they immediately fire the engine up - i'm guessing they think engine heat will "speed" cure this stuff. everybody's in a hurry...

 

I used that "The right stuff" as well as a rubber w/ steel core re-useable gasket. I let it set about 2 hours even though the can said it was good to go immediately. It doesn't seem to be leaking anymore but it'll take awhile for that oil to burn off the block so I can make sure it's not weeping either. Bolts were hand tightened it it was sung on valve cover then ratched in about 5-6 turns to compress the gasket and sealant. (no torque wrench available.) I ran it for about 10 min burned off the oil that was on the exhaust pipe and seemed alright. Haven't put a load on her yet to see if she holds up.

76-79 psi oil pressure cold and 64-69 psi oil pressure after 10 min warm up.

I wish they would have put some oil drains in the block right near the outer edge, it would solve all these problems.

Here's to hoping she holds up with the right stuff

 

I found that the bolt holes in my 85 were partially filled with old sealant. Make sure they are all cleaned out so you get an accurate torque. I had so much trouble with mine I finally went with aftermarket cast valve covers. I used a Felpro rubber gasket which I stuck to the cover with sealant and let dry overnight. I installed the cover/gasket assembly without additional sealant and torqued it pretty good. No leaks after two years.

 

I might have to do that but I hate having to go with non original parts
Even though later she will be so non original when I rebuild her.

 

Yeah I bought these covers because when I go with roller rockers there wont be a clearance issue. Theses are about 3/4" taller than stock and I think they made the engine look a lot better than my old nasty magnesium covers.

 

Hi,
new owner to a 1985 C4. I did all the tune-up, oil change and coolant flush. The valve covers are leaking so I picked up a pair of Felpro from Advanced Auto or Autozone. After reading the Chilton's procedure of getting the driver side valve cover off, I'm a little reluctant to do the job myself. A mechanic friend told me I'd have no problem if I was able to tune the car out. What exactly needs to be done to remove these covers? Some posts have mentioned popping them off in a matter of 15 minutes. You tube makes it look like you can remove these covers with your eyes closed. Who do you believe? If anyone has done this on a tuned port early 1985, please offer some advice.

 

well, I can tell you it's not an eyes closed, 15 minute job. anyone that tells you that is blowing smoke up your ****. not sure how useful a chiltons manual is, and the FSM pretty much gives an overview, and i don't know if anyone has a step-by-step procedures with pics or anything, but I can tell you it's a bit of a PITA. not really hard work, just some work. don't want to scare you, but it's really, a lot of work for what it is, replacing a couple stinkin' VC gaskets - . bottom line though, it all boils down to nuts and bolts - if something's in the way, remove it, loosen it, and get it out of the way. keep doing that until you can lift the VC straight off, or relatively straight off with maybe a little wiggle-jiggle. I can tell you, the biggest obstacle on the right side is the AC compressor/bracket/hoses, and on the drivers side, the smog pump/alternator, and a bit of the wiper motor. you'll need to remove the serpentine belt to gain access to the AC bracket hardware and to remove the smog pump pulley to gain access to that hardware. you'll need to loosen the AC mounting bracket to slide the compressor and bracket forward, slightly to clear the VC mounting flange. same holds true for the smog pump - the VC flange needs to clear any brackets or mounting hardware. there's also a vacuum tube/hose assembly from the rear plenum to the power brake booster that will be in the way. study how things are assembled, and you'll get an idea of what needs to be done. as for the VC's themselves, on the lower side, you have spark plug wire retaining brackets, and the upper side, retainers for some wiring harnesses. basically, you just need to get that stuff out of the way.

if you've never done it, set aside the better part of a day. most of what you need is metric hand tools - maybe a few fractional. you will need a fairly decent tool set. take your time, and don't rush things. you can take shortcuts, but I don't recommend it. the last thing you want to do is go through all the BS to replace these gaskets, and put it back together, just to have it leak again. there's been a few threads on leaking VC gaskets lately, mostly on iron head L98's. I've said this more than once on this subject, you need to be really **** on this repair. do it by the book, and do it right the first time, cause you won't be a happy camper if you have to do it a second time! as an added note, the torque value on the VC retaining nuts is 50 INCH pounds. good luck!

BTW, I see this thread is six years old. back in 2011, I posted about personally using RTV sealant on my iron head 85. I've since converted over to fel-pro silicone gaskets with positive, leak free, results. now, i'm really a happy camper!

final note - from what I remember, 20 years ago, this was a $160 job (parts and labor) at the local chevy dealer. probably north of 3-bills today -

 

We have an interesting problem in common. Do you have a pic of your studs?

 

Do a cylinder leak down test, if you've tried everything could be blow-by. If so try thicker oil, ie 10w40

 

The FSM says to remove the smog pump. You don't really have to do that. There is one bolt that sticks out and keeps the valve cover from coming off. I used to just pull out that one bolt. I cut the bolt off and now I don't have a problem:

 

good point cliff. I assume were talking about sharkface's post on removing the VC from an 85. , on the 86-up L98, however, the 1985 iron head configuration is different. while there are some 85 owners who have managed to get the LH valve cover off without removing the smog pump, I can tell you it is a major PITA. far easier to take an extra 10-15 minutes, remove the smog, and do it by the book.

 

My 86 looks like the first pic in Cliffs post...

 

I used the FelPro permadry gaskets on my 1985 two years ago and not a drip. The passenger side just takes minutes to remove and the drivers sided takes just a few minutes more if you take the cap off of the wiper motor. I replaced an AC compressor twice last week.The first was dead out off the box and I had the passenger side cover off twice to be able to pull out the compressor bolt. Still not a drip after removal and replacement.