Where could this leak be coming from? Oil is dripping off the back of the oil pan cover (the round part) when the engine is running and it is leaving a nice size puddle on my garage floor. First I thought it was the oil pan gasket so I spent a few days slipping a new one on, no difference. After some investigation and a trip to the car wash, I saw that oil is running down the back sides of the engine with it heavier on the passenger side. So, I thought it must be valve cover gaskets, but after beating the covers with a wooden block, I got the warp out of them. (thanks for the ideas on that problem) Now the valve covers are dry. I checked them while the engine was running with a mirror so I am 100% sure they don't leak. The new valve cover gaskets made no difference at all. I still have oil running down the back right and left sides of the block and it seems to start around where the heads meet the block - it's dry above that seam. I don't think the rear main seal would shoot oil up that high and I don't see a crack in the block. It couldn't be coming out of the heads ... could it?? Thanks for ideas.

Dan
85 Bronco
351w H.O.

 

It sounds like your intake manifold's rear rubber seal is failing. Also check the PCV grommet on the passenger side valve cover for leaks. I hope this helps.

Todd
BB79RANCH

 

Hi, make sure the pcv valve rattles when you pull it out if not it could be building up pressure in the engine. It sounds like intake manifold though. John

 

Hey Dude did you try checking for a blow by, this is caused by crank case pressure when the positive crankcase valve is clogged, or just plain old and worn out, also you very well have a faulty rear main bearing seal leak combined with no crankcase ventilation, but that depends on what engine you have, if it was modified and how often you change your oil, old dirty broken down viscosity oil can cause the rear main bearing seal to wear prematurely, however try mixing some food coloring with one gallon of light weight motor oil, you can find food coloring in any grocery store use the whole bottle to one gallon of motor oil, you do know you have to drain the crankcase then fill it with the oil and food coloring mixture, run engine and check while it is running with a large shop towel on the floor, I think this should tell you exactly where the oil is coming from, Good luck hope this info was helpful.


Mableline
Harlem New York City, New York