I have a 307 Olds(it's in a Cadillac) that has leaking valve covers. It's an 87 and has 85000 miles. There are miles of wires and hoses that completely cover the valve covers. I tried to just tighten the bolts and I got exactly one. I don't want to have the valve cover gaskets done for fear I disturb something that won't be put back right or will break.

Is there something I can put in the oil to help the gaskets swell or seal better? And if there is will it be a detriment to other parts of the engine?



Mike

 

No.

You have to take them off and replace the gaskets.

- Eric

 

No boudt adout it!!

 

It's an easy fix. Live a little sir. Go for it!

 

307's are notorious for this issue. The ones on my 86 are shot, too. I understand the non-desire to replace them, but you (and I) will need to soon. I know of no magic formula to seal that big of a leak for long. It will be time consuming for sure.

Only cure is to replace the gaskets, preferably with rubber ones. Felpro has some good rubber gaskets.

If you are good with working on cars, do this yourself and take your time. Allocate a whole weekend although it will not take that long. Do one cover at a time. Label all the hoses and wires and take lots of digital pictures of where they go. Go easy on connectors and plastic parts, as they can break. AC compressor will need to come loose, too. When you get the covers off, verify they are not dented in around the bolt holes. Straighten if needed. Use a razor blade to scrape of old gasket crap. Use permatex sealer around the bolt holes to adhere the gaskets to the cover just for easy of assembly. Lightly oil the sealing surfaces on the heads.

Upon reassy, tighten the bolts in a circular sequence with only a nut driver handle on your socket joints and extensions. Keep going around and around, a little tighter each time. In the end, you will be giving it all you have on the nutdriver handle, and that might be enough at about 5 ft-lbs. AFter a few weeks, retighten.
Torque spec i think is 7, so 5 seems close enough, especially if they are not leaking!

This is how I did my 350 gaskets and they never weeped a bit...

Apparently you haven't seen a 307... I understand his fear; I am dreading that job, too. Makes my underhood resto look like child's play.

 

Thanks, fella's. Let me say that as a mechanic, I know the best way is the right way, and that's to replace the gaskets. I was just hoping to get a little more mileage out of them.

I had decided just to let them leak, as it doesn't use a lot of oil, but the smell of burnt oil is getting stronger and people look at me funny when they see oil smoke coming from under the hood at a stoplight. And it's making a huge mess under the hood, everything is coated with oil and dirt. Yuck.

Not looking forward to this, but I'll be glad to get it done.


Mike

 

Rob: I guess, it just might be a little easier changing the valve cover gaskets in my '67 Delta 88 than it would be in an '87 Caddy. Twenty more years automotive progress and lots more stuff to move.

 

Since you are a mechanic, I think you will get through this just fine. Take your time and label everything. Tape on hoses, and a sharpie pen to mark on the components. Try to remove and move engine CCC sensors, rather than unplugging to avoid possible ESD damage to them. Use bungee cords to hold assemblies up and out of the way.
Avoid putting pressure on the fragile AIR pipes, as they can easily break. Same with the heater valve fitting.

Those old cork gaskets are prolly hard and thin now. They deteriorate with age so new rubber ones are due.
You might want to replace the PCV valve and breather grommets also.

Please post your experience / pictures that may hopefully motivate me to do mine soon!

 

Yep... I would change your 67's gaskets for the cost of a glass of beer.

For an 86 307 - maybe 3 kegs...

Here's what we are up against:


The valve covers are in there somewhere.....

 

Rob how funny, that is exactly how it looks in my car. You wouldn't know an engine was under all that if you didn't hear it running.

I wish I could just remove some of that spaghetti and clean it up a little, but that would be a recipe for all my idiot lights to permanently glow in my face. And probably keep the engine from running right.



Mike

 

I hate dthe original 307(I had the same problem w/ all that **** in my way) that was it my cutlass thats why i yanked it out and dropped a 350 in it

 

Unfortunately, all that crap is needed to keep the computer happy.

What? Replace a running 307 just for leaky valve covers??

Sure sounds tempting cause I would be half way there in disassembly!!

It has been proven that a 72 350 can replace the 307, use all the 307's smog crap, pass emissions, AND get much better performance. Why didn't Olds just do that??

 

I have put off doing the valve cover gaskets on my truck for a long time because of this too. There is a huge mess of vac lines and wires all covering them, and the intake plenum must be removed to access the passenger side.
Who knows! There are many mysteries in the automotive world such as this one, and I've never been able to figure out their reasoning for any of them!

 

I guess the plus side is the driver side one isn't too bad..

Everything on this engine is a mission to get to. Plugs, oil filter, PCV is also under that plenum...

DSCF2614.jpg

 

Might as well put valve seals on, too - you're right there!!

 

I know I'm bringing life to a old thread but has anybody recently replaced the gaskets on the olds 307? I'm in the same boat kinda dreading this job.

 

Yes on non CCC Canadian Delta 88, much easier than yours. The passenger side will suck to do. Follow all the advice above plus make sure to buy the Felpro permadry with the rigid red carrier. The thin rubber with no core are OK but move around unless glued in place. They go hard in a few years too. There are other with the metal carrier that should also work. They cost way more but won't over tighten or move around and won't leak.

 

So just to help out when I go for the 307 valve cover challenge, pass side A/C compressor has to come off, anything else need to be removed from the passenger or driver side?

 

Wow, I forgot all about starting this thread. I never did get to the valve cover gaskets on the Cadillac. I don't drive that car much, and I just learned to live with the oil smell. It is intermittant and tolerable, compared to the can of worms I'd be opening up.

Another reason I never did it is because I don't have a terrific place to work, and I wouldn't want to leave the car sitting all taken apart in the event I got started and couldn't finish.

Good luck with yours.

 

Here are the manual pages from 1986.
While the covers are off, its a good time to check the valve guide seals (intact and tight on the stem) and oil return holes (clear of debris).

Work only while you have patience. The hose nipples of those plastic emission control devices can easily break due to becoming brittle.
If you cannot find the Felpro Permadry+ gaskets, use the thicker rubber Felpro ones (glued to the covers around only the screw holes. Smear a very thin layer of clean oil to the engine mating surfaces and tighten with a nutdriver only in a circular tightening pattern.

 

 

i just picked up a 82 delta 88 that needs valve cover gaskets too. luckily i work at a dealership so i have a shop to work in, but boy am i dreading doing this. I dont really like driving down the road with a trail of smoke following me though.

 

Good heavens. How badly are they leaking? To generate a cloud of smoke behind you from nothing more than leaking valve cover gaskets means either they're leaking like a sieve, or the cause is something else altogether, like bad piston rings, and the smoke is actually in your exhaust.

 

fwiw i installed a set of valve cover gaskets on a new engine a few years back. I popped the covers off to do the vlave lash and pinched one of the gaskets upon re installing and it was leaking alot for a valve cover. It looked like i was doing smoke signals at stop lights lol. If you decide to do it. A nice trick i like is going to the hardware store and buying 1/4 20 thread studs and all you have to worry about is putting the gasket on the studs and your covers on. I have never had this method fail when installing new ones. The first thing that hot oil is gonna hit is the exhaust in my experience.

 

It's pretty bad. And I know it's not the exhaust because when I stop all the smoke stops coming out behind me and starts coming out in front of me from under the hood haha