83sweet928

Just spent hours replacing the oil pan gasket with the new silicone gasket from one of the big three. Everything cleaned and painted, fired her up and the leak is still there. It appears to be coming from the front and leaking dead center right about 4 inches from center. The old gasket was the original and in petrified form and I was certain this was the only leak, could this be a cam gasket leak? With just spending hours replacing the MM and the oil pan removal it is hard for me to imagine logging another 8 hours on a project. Any ideas?

blown 87

Those two are a long way apart, with a timing belt that does not like oil in the middle.

namasgt

are you saying the leak is from front of the oil pan ?

83sweet928

The leak seems to be coming from the top of the pan and dripping down the front of the pan, no way the oil pan gasket is leaking so it has got to be coming from north but can't seem to be able to find out where. No oil on top of the motor and no smell of oil burning, I was sure that the entire leak was the oil pan gasket. The leak is much less now that the gasket is new, it seems I had more than 1 leak.

namasgt

Front Crank seal maybe ? but if it was that I would think it would leak alot.

83sweet928

Maybe I should check the pan bolts again, they seem tight, but not to tight. Funny, no leak on any other bolts just the front.

Ragnar Joensen

Could there be a leak at the upper/lower block mating flange ?

See attached illustration. The oilpan gasket is marked as item 1, the crankshaft seal is marked as item 2, and the mating flange is marked as item 3. Apparently there is no gasket - is this a dry fit or a liquid gasket fit ?


Ragnar

SharkSkin

When you say leaking from the right, do you mean from the POV of sitting in the car(that's the convention) or from the POV of standing at the font bumper looking into the engine bay? If the former, a missing tensioner bolt - the one that penetrates the return galley -- could leak in the location you describe. If the latter, it could be the oil pump shaft seal or outer o-ring. I would expect the main seal to leak more or less straight down the center. Pull the cam gear cover off of the side that seems to be leaking and look around. Cam seals can leak, also the o-rings behind the backing plate behind the gear. The point where the dipstick tube penetrates the block is another potential leak point.

The mating flange is sealed by an adhesive, BTW. Fixing a leak there would be a major operation IMHO. Let's hope it's not that. I think leaks there are pretty rare unless the engine was apart and reassembled improperly.

You may need to clean the area to really find the leak; the fan tends to blow oil around.

Landseer

Ditto on what is said above.

Dialing in on one possible failure point:
The cam gear backing plates, that look like Mickey Mouse ears, mate to the heads with thick, small diam O-rings and are notorious for leaking downwards, making the leak look like its coming from the block seam or the head or the oil pan. If on drivers side, you can pull the alternator and look upwards along the front of the motor towards the cover. Similar on both sides, though harder to see passenger side I recall. Can be done without removing the cam (valve) covers. Behind the ears I think there are two or three thick orings, plus a larger cam shaft O ring and a press-in metal/rubber lip seal. Distributor seal is also a possibility for leaks. Look close at PET for this and you will see. I was so happy when these fixes worked on my heat soaked 84.

Also, as stated, one tensioner bolt mounts into an oilway.

Marine Blue

How bad is the leak? Is it sweating or are you actually getting spots on the floor? Any chance you have a leak in the Timing belt tensioner oil reservoir?

I also saw something similar with my GT this spring after having the MM and Gaskets replaced. The oil lightly coated the top of the pan immediately after the first drive but hasn't changed since. Not sure of the exact cause but whatever it was it has stopped.....

GlenL

When you say "right" you mean "when I'm standing in front of the car it's on my right." Correct? Mostly sides are given from the perspective of the car.

If it's on your right (car left) I'll suggest the oil pump shaft seal. If you replace that remember that it goes in flush with the surface and there's no stop behind it. If you tap in it until it stops it'll fail quickly. BTDT! Doing that job requires the front to be taken apart so a lot of WYAIT is possible like a full re-seal and timing belt job.

Garth S

I found the cam cover seals leaking when suspecting a pan gasket issue - details in this thread from 5 years ago .... gotta love the archives - oh, and BTW, it's still dry today ...

Mrmerlin

if you dont find the leak after following the above advise also look at the oil fill tube that goes into the front of the pan, this connection is under oil level all the time so if you dont have a good seal it will leak.

Note removing the pipe without draining off some oil will result in a spill