Engine Oil Leak While Car is Just Sitting?

[HyperV6]

My 87 Regal T has an oil leak somewhere but I haven't been able to find it yet. I have seen oil on the crossover pipe on the passenger side of the car, some oil on the starter, and coming from the hole in the torque converter cover. I original thought it was the passenger side valve cover so I replace them both. The valve covers did "not" fix the leak. Next, I took off the torque converter cover and inspected the rear main seal. I replaced the rear main about 15 years ago and don't think it's leaking from there especially since I some oil on the starter and crossover at the passenger side. I don't see any oil leaking if I drive the car and look under it while the engine is idling. If I park the car and let it sit for a day or two I will see oil on a metal tray I put under the car. After several weeks of sitting, I have cleaned the metal tray, put it back under the car, and looked at it a week or so later and it had new / leaked oil on it even without running the engine. Any suggestions on what to check next?

Thanks, Craig

 

[Lil Truck]

It's definitely at TR! Lol!

Have you checked the turbo oil return line or oil pressure switch? Tranny lines have oil drops on them?

 

[Frederickdav]

Some guys say if you use synthetic oil it will leak. Others say if you own a Buick Turbo it will leak. I own an '87 Buick T and I use Mobil 1 oil. Guess what? My car leaks oil. Not a lot but it leaks from several places. In the summer of driving it has not required any additional oil. Other than the spots on the garage floor it is no big deal.

 

[WSLN 6]

My car would leak oil with no engine or transmission in the car......

 

[Frederickdav]

My car would leak oil with no engine or transmission in the car......

Quit using oil for brake fluid!

 

[jskarateka]

My 87 Regal T has an oil leak somewhere but I haven't been able to find it yet. I have seen oil on the crossover pipe on the passenger side of the car, some oil on the starter, and coming from the hole in the torque converter cover. I original thought it was the passenger side valve cover so I replace them both. The valve covers did "not" fix the leak. Next, I took off the torque converter cover and inspected the rear main seal. I replaced the rear main about 15 years ago and don't think it's leaking from there especially since I some oil on the starter and crossover at the passenger side. I don't see any oil leaking if I drive the car and look under it while the engine is idling. If I park the car and let it sit for a day or two I will see oil on a metal tray I put under the car. After several weeks of sitting, I have cleaned the metal tray, put it back under the car, and looked at it a week or so later and it had new / leaked oil on it even without running the engine. Any suggestions on what to check next?

Thanks, Craig

Same issue here, if I posted last fall regarding this issue for my car it would have read identical to your post. Your leaking from the back of the oil pan. I replaced the oil pan gasket with a thick cork one from Kirbans and it stopped. For about 2 weeks. Re-torquing the pan bolts would stop or slow it for awhile then it would start again. I will say that I tried switching from Mobile1 15-50 full synthetic to Valvoline VR1 dino and it helped ALOT.

I have considered pulling the pan and just using Permatex Right Stuff, but if you ever want to remove the pan for inspection again while the engine is in the car, good luck. So for now it keeps my garage floor from rusting.

 

[HyperV6]

I have checked everywhere on the engine for the leak. The turbo drain and pressure switch seems to be good. There is a slight leak at the front cover that has been there for many years but I'm pretty sure this isn't cause the leak at the rear of the engine. I guess I should degrease the entire engine and add the dye to check for the exact location. The engine is original and 30 years old now and still running strong. I'd just like to reduce the oil leaking if I can. I have cleaned the breather at the passenger valve cover, the drive side air breather, and installed a new AC Delco PCV. Thanks for the suggestions. I guess I try a new oil pan gasket next time I change the oil.

Craig

 

[TurboTGuy]

Check the PVC valve, when the grommet gets old and when under boost, it tends to let the PVC valve push up and leak a little . Then the oil runs to the back of the engine and eventually to the areas you describe.

 

[earlbrown]

Also, the back on the intake manifold might be a culprit.


I gave up on oil pan gaskets over a decade ago. Nothing but right stuff for me.

 

[~JM~]

If it ever stops leaking...

You might want to check the dipstick.