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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Low87 on March 05, 2012, 07:31:51 pm

Title: trying to confirm leak
Post by: Low87 on March 05, 2012, 07:31:51 pm

I'm losing big time oil, like a quart a week.  I know I'm burning some, but there hasn't been much of a leak.  Tracked down some traces to what looks like the head gasket, rear driver's side.  Here's a pic from the underside.  Can't get a good look from the top.  What do you guys think?
(http://img.photobucket.com/albums/v698/gmccourt/truck/DSC02556.jpg)

It will be about a month before I can do anything about it unfortunately.  Either just replace the gasket or go ahead with my engine swap.  Any ideas to tide me over?

Thanks.

Title: Re: trying to confirm leak
Post by: heavychevy91 on March 05, 2012, 07:58:21 pm

I would take a look at your valve cover gaskets. My .02

Title: Re: trying to confirm leak
Post by: bd on March 05, 2012, 08:45:32 pm

The intake manifold rear valley seal, and/or an oil pressure switch/fitting at the back of the intake manifold, and/or a missing distributor gasket, and/or valve cover gasket(s) are the most likely source(s) of the leak(s) pictured.  However, if you were leaking a quart of oil per week you would have oil puddling under your vehicle.  If the picture shows your worst leak, most of your oil is blowing out the exhaust.  Are there any other oil tracks around the engine?

Title: Re: trying to confirm leak
Post by: bake74 on March 06, 2012, 05:57:34 am

     I agree with bd.  The other thing I would do is take off the valve cover to check torque on the head bolts and check the valve gasket and how it looks.  The valve gaskets can dry out and leak, but like bd said, a quart a week, you should have big time puddles unless you are mostly burning through it with your engine.

Title: Re: trying to confirm leak
Post by: Blazin on March 06, 2012, 07:00:53 am

x2 on what bd said. No way thats a quart a week leak.

Title: Re: trying to confirm leak
Post by: heavychevy91 on March 06, 2012, 07:55:31 am

It was late when i posted. everything bd said as well. thanks.

Title: Re: trying to confirm leak
Post by: Low87 on March 06, 2012, 04:47:11 pm

Thanks guys.  It's definitely not puddling.  Little mark underneath, but not what I'd expect.  It blows smoke on start up, but not while running.  Exhaust is pretty foul smelling though, but I imagine that's another issue.  I'll pull the valve cover this weekend.

Title: Re: trying to confirm leak
Post by: bd on March 06, 2012, 05:32:06 pm

If you decide to persue the oil consumption issue maybe this thread will be of some help...

http://forum.73-87chevytrucks.com/smforum/index.php/topic,22312.msg184287.html#msg184287 (http://forum.73-87chevytrucks.com/smforum/index.php/topic,22312.msg184287.html#msg184287)

Title: Re: trying to confirm leak
Post by: 1980c10 on March 06, 2012, 10:22:35 pm

When the engine is warm after the truck has been driven. With the truck running hold a peice of paper behind the tail pipe and the oil may show up on the paper if you have serious blow by.

Title: Re: trying to confirm leak
Post by: sbx22 on March 06, 2012, 10:30:29 pm

I had a leak pretty much that same location, it turned out to be where the oil pressure line is hooked up. Tighten that thing down just to make sure. Hard to describe, but on the fitting, there are two adjustment points. You'll see what I'm talking about, one smaller, one larger right on top of one another. I would try this before you take the valve cover off.

Title: Re: trying to confirm leak
Post by: Low87 on March 07, 2012, 08:14:47 am

Quote from: bd on March 06, 2012, 05:32:06 pm

If you decide to persue the oil consumption issue maybe this thread will be of some help...

http://forum.73-87chevytrucks.com/smforum/index.php/topic,22312.msg184287.html#msg184287 (http://forum.73-87chevytrucks.com/smforum/index.php/topic,22312.msg184287.html#msg184287)

ha!  Point taken.  Thanks again.