73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: austin18 on November 19, 2012, 05:11:04 pm

Title: oil leak
Post by: austin18 on November 19, 2012, 05:11:04 pm

i got oil spraying on the passenger floorboard of my 87 305 silverado. I just redone the intake gaskets and valve cover gaskets. i have looked under the block and cant find nothing but a lot of sludge. where is my leak coming from?

Title: Re: oil leak
Post by: 84burb on November 19, 2012, 06:01:45 pm

Welcome
If it is outside, I would suspect the valve cover or intake manifold gasket.
If it is inside the cab, I would guess it is coolant coming from a loose heater hose at the firewall or a leaking heater core.

Those are just guesses until we can get more specific info.

Title: Re: oil leak
Post by: 454Man on November 19, 2012, 06:52:01 pm

Rear main?

Title: Re: oil leak
Post by: 81_Chevy on November 20, 2012, 11:19:15 am

oil pressure sending unit?

Title: Re: oil leak
Post by: Blazin on November 20, 2012, 10:55:57 pm

First thing you can do is rule out the heater coore, or lose heater hoses as this is an oil leak, and they have coolant in them.
Second thing to do is clean ANY, and ALL sludge, dirt, oil, etc. etc. from the entire engine, transmission, frame, front supension, etc.
Then start it up and maybe see where its coming from.
Did you make sure the valve covers flanges were nice, flat / strait?
Did you use a high quality rubber valve cover gasket?
Did you thoroughly clean and inspect the valve covers for holes?
Did you inspect the oil presure sending unit to see if it was leaking, at the threads, or through the sending unti itself?
Did you throw away the end gaskets for the intake, and use a TOP QUALITY RTV silicone gasket maker? If not that would be the first thing I would suspect is those piece of crap end intake gaskets!