2005 GMC Yukon with 4.8

Google brought me to this forum, and I see that I have a common problem. Smoke pours out of the tailpipe at start up and then disappears after I am about 1/8 of a mile down the road. The tailpipe is black.

I have confirmed that there is no PCV valve (this is a 2005, so there is just the orifice that they started installing in 2004). This is on the driver's side.

I have seen the suggestion of a catch can.

I noted also that there appears to be a tube that goes from the passenger side valve cover to right behind the throttle body at the front of the intake manifold. Couldn't the engine be sucking oil from there just as easily as from the PCV (or orifice)?

For what it's worth, I had this same problem about 8-9 months ago, for about 3 weeks, and then it went away on its own. Now it is back. This is why I do not think it is my valve seals or guides, even though I just turned 200,000 miles. Two weeks ago the engine did not use a drop of oil, then one morning I turn it on and cover the driveway in smoke and use a quart every 100-200 miles!

Suggestions and advice are welcome.

I am considering right now a pressure and leakdown test and perhaps two catchcans (one for each valve cover tube).

Google brought me here for my smoking problem, but this forum already has me considering a cam, headers, Trick Flow ported heads, a 3,000 stall torque converter, lower gears, and maybe a supercharger or a turbo!

But let's get my smoking problem fixed first.

 

 

i also am having same issue..


2005 GMC 1500 CCSB Z71 5.3

 

Please keep me updated on any solutions!

 

Thats a lot of oil, far more than I except the PCV system to account for. It sounds like you know what to do first; leak down and compression test. I expect with that many miles you will find sub-bar compression and leakdown performance, meaning its about time for a rebuild. But do those tests first and see what happens.

Welcome to PT.

 

Atomic, thanks for the welcome. Please note, however, in my first post, that this was a problem that I had 8-9 months ago, and it went away on its own. In other words, it stopped smoking and did not use a drop of oil between oil changes (every 3,000). Now it is back. Frustrating.

The fact that it went away makes me want to believe it is not valve guides or seals. Also, no smoke while driving and decelerating. It just pushes out a huge plume at start up and for about the first quarter mile or so.

 

Camperhead, check out this thread, in which others say "valve seals," but somebody else chimes in with the PCV issue. https://www.performancetrucks.net/fo...st-how-372077/

 

I saw that, but also think its a good to go ahead and do those tests. Where are you located?

 

What color is the Smoke? Have you pulled the TB and looked into the intake? I have seen oil puddle and then when it gets to a certain point get sucked into the heads in large amounts. Causing smoke on initial start up.

 

Senoia, GA (south of Atlanta)