Hey guys -

Had an inspiration the other day on getting the stock oil pan to seal. My idea came from the piston engine world, this gasket in particular -



It's a silicone molded gasket and has compression stops in the gasket to keep it from crushing the silicone too far.

My idea is this. Get a pack of stainless metric shims from McMaster-Carr, 1mm thick, and 6mm ID for the 10mm bolts and 12mm ID for the motor mount bolts.

Put a light coat of RTV on the shims and stick them to the bottom of the engine. Then, do a typical bead of RTV all around and install the pan. The shims will keep some small space between the pan and the engine. This should make for a thicker film of RTV to seal up and fill any irregularities.

BTW, I'm also a fan of Rich's (GoodfellasFD3S) solution - get a new oil pan. A pan that's been pried off the engine a number of times just isn't flat and won't be flat again. But, I'd like to find a solution for all the poor souls with used and un-flat pans.

Any input? I'm doing a motor right now for one of the local guys and I'm tempted to try this. Bad this is if it REALLY doesn't work I'm for a bitch of an oil pan leak repair. I HATE doing them in the car.

Dale

 

Im pretty sure you know this but I used "The right stuff" 1 minute along with a banzai brace. Mind you this was an used pan pried off like you said. Dry as a bone until this date going on a year now.

 

Dale, I was last year working on an inexpensive gasket solution but I pulled the plug cause it was really difficult to get them to stay still in the machine causing irregularities. You've got me wanting to dust off the project...

 

I remade my metal turbo piping gaskets out of adhesive backed Viton sheet from McMaster-Carr so they are re-useable and was thinking how cool it would be to have an oil pan gasket made from the same.

I tried the Silicone, bit the soft durometer material available squeezed out to easily for the two bolt gasket design- spacers built into the gasket would have helped there.

 

The metal turbo gaskets are VERY reusable, BTW. Only when they start looking really sad and tired do they need to be retired.

I really wish there was a foolproof leakproof solution for the FD oil pan. My car has a very slow oil pan leak, last time I went through the motor I had the engine upside-down, spotless and clean, used the Right Stuff grey squirt can RTV, torqued all the bolts properly, AND used an oil pan brace. Still leaks. A new oil pan would definitely have helped, but that's just ridiculous to throw out an oil pan every time you remove it.

I think a lot of the problem stems from the design of the oil pan with the large flat area at the back that the motor mounts attach to. That area warps and bends quite easily, and having that bent up along with having the motor mounts attached there just isn't helping.

Any other thoughts? I'm really interested to give this a shot.

Dale

 

The other issue I see with the oil pan sealing surface is that it consists of 5 sandwiched parts and 2 dissimilar metals. These surfaces are not machined perfectly flat to one another.

Dale, personally I do not think your idea will work well using the spacers unless you use in conjunction with a gasket designed for such use, but I hope I am wrong. To me the oil pan will bend more using the spacers due to the torque applied to the oil pan by the motor mounts. I guess you would need spacers for the motor mount holes as well to alleviate those problems.

I say give it a try and let us know how it works out

Whats the worst that can happen? It leaks

 

I'm talking about using spacers on the motor mount holes as well, so all bolts that go through the pan will have a 1mm spacer between it and the engine.

The "sandwich of dissimilar metals" argument doesn't hold water as FC's have nowhere near the oil pan leak issues that the FD has. A lot of that comes from the design, FC's have one engine mount that attaches to the center iron on the passenger side through the oil pan. It makes for a smaller flat surface and it's in a "valley" with the bulges of the oil pan on either side.

My theory is that the spacers will give some room for more "body" of RTV to occupy. With a warped pan, you'll have spots where it's compressing all the RTV out and spots where you have a good body of RTV. I think those too-tight spots are where the oil is finding a way out.

Dale

 

The metal turbo gaskets are VERY reusable, BTW. Only when they start looking really sad and tired do they need to be retired.

Could you explain this to me so I stop wasting money coming up with different solutions?

From what I see a new metal FD intake pipe gasket is one layer of thin sheet metal with an embossed ring on it. When you tighten the two bolts at the flanges the embossed metal gasket is crushed flat and at any higher points where it would leak the embossing is not quite crushed as flat.

If you try to re-use it it would seem to me that unless you got the gasket back EXACTLY where it had been (physically impossible) then there is a chance you will have higher points in the flanges able to leak.

In a pinch I have re-used the metal intake gaskets with the addition of Hylomar on each side. Basically, I felt it was just like using Hylomar on the flanges but with twice the film thickness possible due to the addition of the flattened metal gasket (buttering both sides of the bread).

Please explain it so I stop wasting time and money over thinking it.

 

Even if the metal gasket is flattened, they DO seal well. Sometimes it's counter-intuitive, but I've re-used mine COUNTLESS times with zero leaks. And, yes, this is with pressure testing the system.

The only time I've seen them get sketchy is when the coating starts to come off the gasket or they're mangled and sad looking. "A bit flat" is fine.

Dale

 

Textured mating surfaces by tapping w/ a center punch, no gasket and the right stuff:

5+ years
numerous auto-x's
several HPDE's
not even a drop of oil is leaking from my engine

I had read on here somewhere about dimpling the pan and block with a centerpunch for 2x reasons:

to give the adhesive a rough surface to adhere to and so there is more friction b/t pan and block so that it does not shift and disrupt the seal you have created.

AFA those spacers/shims on the bolts, you are transferring all of weight, vibration and torque of the engine through them. I would not be surprised if they deformed. IMHO doesn't seem like the best solution esp when people have gotten a seal w/o them.

Hope this helps.

 

I've also seen engines that have had the "dimple treatment" and STILL leaked. It's another technique, not a fix-all.

Dale

 

I've re-used mine COUNTLESS times with zero leaks. And, yes, this is with pressure testing the system.

Thanks, I have a tendency to over think things!

 

Honda V6 engines use that type of gasket with a shim style bolt on the valve covers and we still have to use RTV at the corners of the hump to keep it from leaking.

The flat metal gaskets with the initial raised ring I have reused dozens of times before even firing the engine and I've never had an issue with one leaking.

I don't have any experience having to attach the oil pan to the engine yet and see if it leaks but from all the threads I've seen I don't think you'll get much real information from it. Every process has people that it worked for and people that it didn't, and unless people go through the hassle of posting how clean they had the mating surface, the torque sequence, pictures of RTV bead size and etc... I don't think you can really compare things very well.

 

Weird. I have seen The Right Stuff work some straight up sealing MIRACLES... Is it possible that they are leaking from the legs of the rotor housing/iron side plates?


I seem to remember something in the FSM about sealing this lower area.

 

That's always possible if the engine was poorly assembled. But, you're sandwiching two very rigid parts (the iron and the rotor housing) together. The rotor housings have small grooves to help retain the RTV and enhance the sealing.

The FD oil pan always seems to leak from the back, which is a large, flat surface with the motor mounts attached.

The more I think about it, the more I see a few factors -

- You have to have SOME RTV in place to seal. If you have a warp in the pan, it can push all the wet RTV out during installation (you get a metal to metal contact) and the oil finds a way through that joint.

- The motor mounts are high torque and can also press the pan hard to the motor, again making a metal to metal seal and leading to a leak.

Using the spacers would give a little bit of room for RTV to find a home, sealing it up.

Still thinking about this one.

Dale