Oil leak detective..

[Hemihead2]

My situation- Fresh 340- (used oil pan) No oil leak when running but a slow drip and small puddle after shutoff. Worsened with a switch from 20W-50 to 10W-30…Thinking the rear pan isn’t sealing to the main…am I correct in thinking if it was higher up- ie. an oil galley plug, cam plug or rear main- it would leak while running?

No oil on the flex plate or converter but it does pool in the bottom of the bellhousing after shut down.

Trying to build a consensus before I tear into it. Definitely not looking to pull the engine if I can help it. Thanks all!

 

[junkyardhero]

the absolute first thing i always check is the oil pressure sending unit & line. when those leak the oil is somehow able to wheedle waddle its way down into the most unlikely of places.

after that, i'd dry everything real good with a liberal application of cleaning of brakes and then dust the area with baby powder or talc and see if i can pin point the source using that discoloration as a guide.

 

[Hemihead2]

I’m running a Melling HV pump if it matters. Anyone have clearance issues using a stock pan? Seem to remember hearing about a need to clearance the pan for it on a different thread but I may be wrong.

 

[66fyssh]

I would have bet an oil leak I had in my 5.9 was the rear main seal. For years it made my oil pan and bellhousing wet with a few drips on the garage floor. I gave up trying to find it and just learned to deal with it.

Recently replaced the stamped steel valve covers with cast aluminum and the leak is gone!!!

As @junkyardhero said, triple check sending unit and I'll add valve covers also.

 

[Just Send It]

Get a UV oil kit and a blacklight. Then just follow the drip. No guesswork.

 

[1973dust]

FWIW, I'd also check the rear of the intake carefully. I had one that was leaking there at the China wall and was able to stop the leak by using brake-clean and placing a "fillet" of black rtv along the back of the intake with a gloved finger. I think I just didn't use a tall enough bead when I installed the intake.

 

[Frankbassman]

Just went through this with a 5.9 magnum.

Mine was a pan gasket. Same symptoms. It LOOKED like a rear main seal leak till I took the flexplate off and sprayed with brake cleaner. Ran engine till warm and shut off. Then it was obvious that the leak was between pan gasket and block.

Flex plate was dry.

Hope your issue is the same! But it is a b**** on a dart. Mine was on my 2000 durango.Good luck.

-Frank.

 

[George Jets]

Oil always leaks down from high up above.

Like a river it will find a hidden path to the bottom of your engine and drip on the floor.

Even if it's only the size of a quarter after 2 weeks, it will still pizz a guy off.

Good luck on your project.


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