Thread: Oil leak is driving me crazy!

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I have been fighting never ending leaks on the front and rear of the oil pan on my 383. I have had the pan off three times, the last time I used a different pan and used another new one-piece gasket. And the @#$%&*+ thing still leaks. The first time I used no silicone. The second and third time, I used silicone in the corners only. I replaced the pcv valve with a fixed orifice type unit, and that made no difference. Do any of you have recommendations on sealing this thing up? I am going back to dino oil with a zinc additive as I only had an occasional drip before I switched to synthetic.

First, are you sure it's the pan and not the front and rear crank seals?

Are you trying to seal a chrome pan?

Don't feel bad, I have a car up on stands right now that after trying to seal the chrome pan for the second time is getting a new steel pan.



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The front and rear seals are fine as it did not actually leak with dino oil--just an occasional drip. The first pan was not chrome. The present pan is chrome but I used my Dremel tool to rough up the mating surfaces.

Get a small can of Permatex "The Right Stuff"
Looks like Cheez Wiz can
Apply a small ribbon on either side of the gasket and install the pan.
Let it sit over night.
Fill with oil, and fergit about the leaks.
Been there done that !!!!!!!!!

there are different combos of pans and gaskets---why are you using a one piece gasket?? they have different combos of thickness for the front/rear part and you may have wrong combo--changing the pan to a chinese or el cheapo nockoff will not help--

and is your engine one or two piece rear seal and what front cover??
Rear leaks can also be from between the rear cap and block where pan gasket fit has no bearing

The block has a two-piece rear seal, timing cover is a stock sbc painted black, the first pan was a stock Chevy pan and I used the 4-piece cork and rubber gaskets, and the second one is the pan that has a skid plate welded to it. It requires the thicker gasket which I used (Fel-Pro, I think). I chose the one-piece gasket because it came highly recommended by guys on other forums. They reported no leaks using one.

pan has skid plate welded to it really doesn't tell much about it--I'm assuming that its NOT a oem pan????

Correct. It is not an OEM pan. Chinese? Possibly. It seems everything else is made there. Here is the link:

Trans-Dapt Performance Products 8910 - Trans-Dapt Performance Slam-Guard Oil Pans - Overview - SummitRacing.com

I hate oil leaks – I’m convinced that they are from the devil himself and about as hard to overcome!

I’m a huge Milodon fan and have used a combination of their pans, pumps, studs, and one piece gaskets for multiple builds and have had phenomenal success in regard to no leaks. But these have been new builds on an engine stand in very clean conditions. Once things are in the car – well – not so easy.

To your particular case, this may be helpful – it’s a “real life” story from a Camaro with a 327, but same situation, i.e., leaking like a bugger and really frustrating me and the fellow who owned the car (not to mention his wife’s displeasure with the oil puddles in the driveway!). This all took place on a concrete driveway (outside of course) with the car on ramps! Pan was an aftermarket cast aluminum that looked really good as far as the fit and finish. We stripped the old nasty gasket and scuffed the block with 100 wet-dry paper, then wiped with solvent (acetone as I recall – I was a bit “buzzed” afterwards – but maybe it was the Budweiser’s?).. Next we laid out a bead of black RTV and spread it well into all the junction points, let it get tacky and pressed the cork gaskets and rubber in place – holding them with masking tape and let it sit for a couple hours (more Bud at this point as I recall..) We roughed the sealing edges of the pan with 100 paper as well, cleaned well with solvent and dried real well before putting a nice fat bead of RTV all the way around and immediately placed the pan and bolted it snug – not murder tight, but enough to goosh the RTV out the sides. I know there are torque values for pans, but we used the “calibrated wrist” with a ¼” drive ratchet. Let it sit all night before firing up and that bad boy never leaked another drop.

I don’t know if we were lucky or if the RTV on both sides of the assembly in all the right spots working with the cork did the trick. I do know that the ¼” drive helps as it’s really easy to ruin cork with a 3/8” or heaven forbid a ½” drive. I know that clean is good - maybe it was because we we’re on our backs working slow with a drop light in the driveway, but it all sealed up without leaks.

Hope this helps, Lynn – good luck on this one,
Glenn

Before i set a pan on the engine i see how 'flat' it is and if used i see if it has been over-tight and the bolt holes pulled down - there is supposed to be a slight airgap at the bolts so they can pull down, some people overtighten and the bolt holes get pulled inward so the bolt makes contac befor the rail. I check for 'flat' because it is industry standard that it can 'rock' corner to corner a full 1/4" and be considered 'in tolorance' (as per moroso catalog and instruction sheet).
When i feel i have something to work with i use the 'right stuff' permatex or permatex 'ultra' (i think it is called) and goop up both sides of the thicker 'felt' type pan rail gasket and when i pull the bolts/nuts down i am careful to not overtighten - you are safe as long as the gasket don't push.
When troubleshooting a leak, think about how the oil is sitting in the pan. It ain't nowhere near the pan rails, you will have to be on a pretty steep grade for it too leak out of the lower parts of the crank seal area. Take a pan and dump oil into it and you'll see what i mean. Something is really screwed up if it sits there and oil dribbles out the pan rail, you can pretty much rule that type of problem out. So if it is leaking while sitting it likely ain't the pan.

First are you sure the leaks not comming for above like the oil sending unit???
Second, We used a ball peen hammer to peen all the bolt holes from the inside out,
on all the Ambulance motors we did with tin oil pans on them and they did very well
for years with no leaks. If you have never peened a pan, Just go around all the bolt
holes and give them two or three hard taps so that they are beveled out just a little.
This is done from the inside out, so towards the bolt head. Believe me it works.
Kurt

2X what Da34guy says. Get Permatex The Right Stuff.

more likely excessive blow by . oil doesn't really leak at many places. it is blown out. see it a lot. fat tune, washes down cylinders which lets compression leak by rings . i us the moon breather on every build. relieves the pressure so no leaks.

Dump the one piece pan gasket for sure, I agree on checking the pan to the block surface for true. Over tighting is a huge no no. and I suggest doing the front and read bolts last after the side rails are done. I run a chrome drag pan with a good old cork gasket, goop on the corners only. The front and rear seals are differant sizes suggest you be mind full of that.

Back when I redid my motor I thought I had a rear main seal leaking all the time. After pulling the motor I found it was my gasket for the distributor. Surprising where leaks can come from.