I have a slight leak from my oil pan gasket, its not that bad, but I was wondering what kind of RTV I can use to repair the leak? I dont mind spending a little more money for a quality RTV, so if anyone has any ideas please let me know, thanks

 

I'm in the middle of a rebuild myself and done a lot of reading. A popular brand is HONDABOND sealant and most recommend using it WITHOUT the gasket...being sure to let it cure completely. Depending on where it's leaking, you may have difficulty in "fixing" it. The best thing to do might be to remove it completely and start over....but that's a lot of work.

 

The FD oil pan is going to leak a little bit by design. I have tried many methods of sealing, and short of a $400 aftermarket oil pan, the best success I've had seems to come from using a paper gasket with sealant on each side. Use a liberal amount of sealant in the back where the motor mount holes are, but not in such a way as to let it get IN the motor mount holes.

Be very careful when removing the oilpan, the flange warps easily and this will make it leak oil very badly.

I usually use ultra black RTV from permatex, but they also make a super JDM type R sealant called "the right stuff" that costs about 13 bucks per tube that some people swear by. I have used it before and didnt notice any difference versus the regular ultra black for 5 bucks a tube.

I have also tried hondabond, which some people swear by in other car circles, and still had leaks with it.

The general procedure is to clean both mating surfaces to bare metal, I use a wire cup brush mounted to an angle grinder and/or a flat wire brush mounted to a drill. Then clean off both surfaces with a clean towel soaked in brake cleaner. Wait for it to dry and then apply sealant to both surfaces, put the gasket on the block and mate them. I do this without turning the oilpan upside down to as to keep any drainage from the pan off of the mating surfaces. Tighten down in 2 steps over several hours as recommended by the sealant manufacturer.

 

I just realized you may have meant you were going to try to seal the pan without removing it. This will be near impossible and you will just make more of a mess without affecting the leak. The leak originates from inside the pan (obviously) and so you applying some sealant to the outside won't help the inside seal any better.

 

I have a brand new oem fd oil pan gasket if you want to try the silcone w/oem gasket seal captain mentioned up there.

 

Most FD'ers think the OE gasket is the cause of oil leaks, not the solution for eliminating them. Read this somewhat typical thread:

https://www.rx7club.com/showthread.p...easier+oil+pan

 

I agree that use of a gasket alone is a sure way for a leak, and RTV alone is a better option.

IN my opinion:

gasket alone < RTV alone < RTV plus gasket < oilpan brace in conjunction with RTV/gasket < aftermarket o-ring oilpan

 

Gasket = devil

do not use. that is all.

sealant = permatex "the right stuff" for imports

 

"For imports", lol...as if imports make so much more torque than domestics (sarcasm), that they need the extra sealing ability. I just love creative marketing.

 

The Right Stuff for Imports Gasket Maker was specifically designed to perform under the higher torque loads caused by engines with closely spaced bolt patterns (typically import vehicles, particularly Japanese).

 

hey guys thank for the help, Im thinking what I may do is remove the old gasket, and use the RTV that some of you were talking about. It seems to leak more around where the engine mount are? I guess this is common place. Alright , I wll give it a try, Thanks again

 

every time you remove an FD oil pan then tend to get warped a bit around where the motor mounts bolt to. hammer these areas flat before reinstalling. for best results in order of best to worst:

1) permatex ultra black or hondabond on either side of the oil pan gasket
2) permatex ultra black or hondabond on oil pan surface, no gasket
3) oil pan gasket alone, it will leak if the engine has been rebuilt as the motors are decked in series runs and swapping irons and rotor housings will result in uneven pan mating surfaces. at the very least i would suggest putting a dab of RTV at each seam.
4) leave it alone and add oil when needed, ******* FD oil pan removal is one of my biggest pet peeves about these cars...

the only people who say gaskets are the devil are people who don't know what a torque wrench is.

 

?? That's just a plain black silicone sealant?

Dave

 

You have obviously had a huge amount of first-hand experience with this. However, I would respectfully like to disagree somewhat.

Item "A" will usually only occur with a gasket (or too much cured silicon seal) in place, allowing the pan to be warped as the gasket compresses or takes a set under the torque of the engine mount and other bolts. The gasket taking a set allows the engine mount bolts to loosen, possibly creating a leak path.

Item "B" - see Item "A" answer

Item "C" - see item "A" answer

 

I just had a discussion on this with a friend that is a long time Toyota mechanic.

They never use gaskets on oil pans or auto transmission pans.

For engines they use Toyota FIPG Black and for tranny's FIPG orange.

He asserts it "will not leak", so I'm thinking of giving it a try.

 

That's a pretty ignorant thing to say about a mechanic...

The gasket should not be used because of an engineering oversight/compromise. The gasket is between the motor mounts and the engine. The weight of the engine and repeated pressure applied at the mount mounts compresses the gasket unevenly and permanently.

 

...and it doesnt do the same to the sealant? how does that argument benefit the use of sealant versus the use of a gasket? the same conditions are going to be present with either.

 

Simply install one of our oil pan brace kits.

http://www.banzai-racing.com/product..._pan_brace.htm

 

Answer:
Not if the bolts are torqued before the sealant cures. Any areas that would have taken a set or tended to collapse are compressed metal-to-metal when they are torqued, preventing any further movement.

Dave

 

Correct. Bolts are designed to create a clamp, and if you let the sealant cure first, the bolts won't be able to do their job. If you retorque on cured sealant, it will detach from the metal surfaces or tear and create leak paths.

Actual gaskets are the other way around - they have high shear strength so that when the bolts clamp down on it, it won't tear.

(Not that you needed backup dave, I thought I'd explain it differently)

 

Thanks, Dave. More (correct) info is always good!

Also, modern gaskets won't usually tear (I've had old crappy cork gaskets tear lots of times), but they can (as we know in the case of the FD oil pan gasket) take a set and cause bolt loosening and/or leaks.

Dave

 

I use "the right stuff" by Permatex. It dries a lot harder than most silicones. I never use the gasket as it will always leak. Make sure everything is clean and the oil pan is free of bends on the sealing surface. I also install an oil pan reinforcement brace that is available from a few of the vendors on here. The pan will ALWAYS leak again without a brace.

 

Mine hasn't leaked so far, but I only did the job (with Permatex Ultra-Gray and no brace, but "dimpling" the pan - link: https://www.rx7club.com/showthread.p...easier+oil+pan ) about two years ago. So, IMO, the jury is still out on whether my fix w/o a brace is "permanent."

Dave

 

IF you indeed have metal to metal contact, then you have no sealant in between. So how exactly is the pan to stay sealed?

Likewise, if you use a gasket, you're saying the bolts get left looser than if you use sealant only? Well no wonder you guys get leaks.

FWIW, tightening torque for oilpan fasteners is listed in the FSM. The root of the problem here is that all the small bolts get torqued to 104 inch-lbs, and then in the back all the sudden the motor mounts get torqued on at 68 foot-lbs. That means the torque in the back is 8 times higher than in the front. It also puts a lot more stress on the area between the last small bolt and the front of the motor mounts. Which is consequently where leaks always occur!

Whether you use a gasket or sealant, the motor mounts are constantly compressing and releasing, compressing and releasing, each time you apply and release throttle, shift gears, accelerate or decelerate, etc. Of course the seal is going to be broken loose eventually, it's a bad design.

I feel that if you use a gasket you have a thicker medium there to absorb some of this motion and also the torque of each bolt, whereas with sealant alone, you simply wind up squeezing all your medium out the edges (inside and outside edge) and wind up with very little sealing material where it counts...on the pan flange.

 

i havent heard anyone hear mention how to use rtv or gasket maker properly the reason it works at all is because you have to let it set before you assemble and tighten your parts that way it provides a "cushion" between the two metal parts. If you assemble and tighten things immediately you will very definately squeeze it all out.

Follow instructions and you will find that most if not all recommend a 15 minute period for which to allow the sealant to "skin over" before assembling and another period of time about 20 mins before torquing fully.

That is the only way to ensure a good bond between surfaces and enough 'pillow' on which to keep surfaces separate.

in every case i know of, properly used gasket sealant has outperformed conventional gaskets with obvious exceptions of course such as head gaskets, etc.

do not tighten wet sealant or all you will get is blobs on either side of where you need it and nothing between.

There is also the option of using ready cork/rubber gasket roll and cutting out your own which has also proven quite effective.

Crush type gaskets (most metal ones) are also not intended to be re-used and often call for replacement that is because upon torquing you "set" the gasket and by re-using it you can develop "wrinkles" in it by attempting to "reset" it. this is not good. so just splurge and buy new ones or go with a proper rtv and follow all directions for your application