One-piece oil pan gasket leak

[Michael M.]

[Joe L.]

Re: One-piece oil pan gasket leak

Mike------

I do not know what the differences are, if any, between the two Fel Pro gaskets. However, either should seal.

Your pan is an original style pan with the "thin" front seal, so you are using the correct one piece gasket. In addition, if you were to use a gasket with the "thin" front seal on a pan designed for the "thick" front seal, you would have a leak MUCH, MUCH larger than the one you report.

[Timothy B.]

Re: One-piece oil pan gasket leak

Michael,

That's a tough call to say where the oil drops are coming from. The damper can pass oil through the keyway slot and a valve cover leak can also show up below where you mention. The low point of the timing cover is the lowest point in the front so take a breath and look carefully at other places.

That's a bunch of work to keep doing over and over. When I installed a new pan gasket on my 67 I used the four piece GM gasket with a smear of permetex ultra black everywhere even on the timing cover and rear cap where the rubber sits. I stuck the gasket on and one more thin smear on the other side then installed the pan and no leaks yet.

Keep in mind the engine oil pickup does not like RTV so not to thick..

[Jerry G.]

Re: One-piece oil pan gasket leak

I stopped using the one piece on the race car. I was chasing leaks constantly. I went back to four piece and good silicone and no more problems. I think the one piece may be too stiff and has problems conforming. Just my expirience.

[Thomas B.]

Re: One-piece oil pan gasket leak

Mike:
Similar thing happened to me recently, in my case the culprit was the valley in the timing chain cover. There was a little bit of front to back “play" in the gasket when pushed up in the groove. I massaged the inner lip of the timing chain cover to remove the gap. The old multi piece gasket has a fair amount of RTV sealer of the front seal that was accomplishing the same objective.

Tom

[Edward J.]

Re: One-piece oil pan gasket leak

Mike it seems to be a issue with the one piece gaskets, I have the same issue with my 72 and have a 4 piece gasket in hand to redo the pan on my car. mine is leaking in the same area.

I used the 4 piece gasket in my 63 on the engine rebuild and have no leaks. It takes careful cleaning of the surfaces and when ready to install the gasket I use 3M weatherstrip adhesive for the gasket and rubbers, be sure to use only a dab of RTV at the cornors to much may make the gaskets slip when tightning. and torque the gasket in at least 3 or 4 steps, and let set.

[Michael M.]

Re: One-piece oil pan gasket leak

Thanks to all for the responses.

Your pan is an original style pan with the "thin" front seal, so you are using the correct one piece gasket. In addition, if you were to use a gasket with the "thin" front seal on a pan designed for the "thick" front seal, you would have a leak MUCH, MUCH larger than the one you report.

Michael,

That's a tough call to say where the oil drops are coming from. The damper can pass oil through the keyway slot and a valve cover leak can also show up below where you mention. The low point of the timing cover is the lowest point in the front so take a breath and look carefully at other places.

In my initial search for leaks, I had carefully dusted (baby powder) all around the valve covers and they are dry since a recent gasket change. Same with the front crank seal. One of my suspicions is oil somehow wicking through the timing cover gasket and showing up at the lowest point of the timing cover.

[Joe L.]

Re: One-piece oil pan gasket leak

Mike------


A few things:

front oil pan seal radius:

1955-74 small block (Corvette and otherwise)-----2-1/4"

1955-74 GM SERVICE oil pans after about 1976 (i.e. pans with 6 digit part numbers)----2-3/8"

1975+ oil pans------2-3/8"


As far as engine sealing technology, things have improved. Later Gen I and Gen II small blocks as well as Gen III and IV use one piece oil pan gaskets and they seal very well.