spwwalsh

I have an oil leak on my '83 Chevy C10. I have recently put in a new/rebuilt 350 done by a machine shop.Here is the odd thing about it. It only leaks when I am driving. For instance, I cleaned up the entire under carriage and turned the truck on and let it run in park for over 30 minutes. Itdid not leakat all, in fact I dont have any spots on my driveway since then (18 hours of sit time). I can then take it out for a spin and then when I get back, the oil is all over the undercarriage again from being sprayed, wind, etc. Very strange and I am baffled. I have retorqued valve covers, oil pan, checked gaskets, etc. Any thoughts?

cams 98 silverado

hey... welcome to the forum. Now are you absolutely sure its oil dripping? i had the same issue. it would sit at idle and not leak a drop of fluid but once driven and the fluids pressurized more it would pee... when it leaks does it leak in the front area like as if it dripped from the head gasket? check and see if it is oil or coolant. my truck(98 silver with 350) leaked down from the passenger head to the chassis. it looked like oil until i did the test... its weird but take some of the leaked fluid, taste it. if it has a sting tingle feel on the tongue its coolant. look at the front of the engine by the head gasket. like take a good look after taking a small drive around... look by the intake gasket and all over there... it could be an intake manifold leak... so look all in there. i thought i had head gasket leak in which case it made me miss half of school so i could work on it. i put some alumaseal in the radiator and it fixed it right up. so check all around and i hope you can find the fix easily. good luck. and again welcome to the forum!

spwwalsh

Thanks, I will take a look. You provided some good insight and I will let you know my findings. Thanks for taking the time to reply.

spwwalsh

Well, it's definately oil. It seems to be coming from the oil pan, fly wheel area. I took it for a spin around the block, stomped on it and let off after a second, just to get some pressure built up and not enough to spray everywhere withwind.parked it and examined. Still dont really know. I have an aluminum pan and a bad *** gasket so it is hard for me to believe that it is leaking.

shawnvw

is it coming from the front or rear of the engine? sounds like it might be the rear main

spwwalsh

It looks like it is coming from the back side of the engine. Most of the accumulation is around where the pan connects to the enginenear the flywheel. It is just hard to see exactly where. Thanks for your post.

shawnvw

I would say it is the rear main if the intake insn't leaking. You may want to try an oil stop leak. goes in with a fresh oil change. Takes about 500km to work. What it does is soften up the seal again. A lot of times the seals get hard and loose their ability to seal around the crankshaft.If there is another problem with it, or if it is too far gone, then the stop leak won't work. But at $10\bottle, it might be worth it to do it through 2 oil changes and see if it helps. If not, you're looking at either pulling the tranny, or the motor to get at the seal

spwwalsh

Thanks for your time and recommendation. Never thought of that, couldn't hurt. If I can isolate it to the rear main/seal I will give it a try. I will be taking a good look tomorrow, I have about 3 hours of dedicated time I can put into it.

kerpal

Definitely an oil leak... Might be the power stirring oil leak... I think you better change the power steering oil pump aand the hose..

spwwalsh

Oil leak is fixed. It was an imperfection in the chrome oil pan on the back passengerside.The rubber gasket didn't mate properly and theoil leaked from there. It has been replaced, new pan, gasket, new rear main for good measure.

Dry as a bone. Thanks for your comments everyone. Finally, I can enjoy the truck with no leaks in the back ofmy mind.