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Smokin

turbojimmy

Full Member
Joined
Jan 10, 2012
Messages
244
Location
NJ
My '07 has about 140k miles on it now. I've noticed recently that it smokes A LOT at startup, but at random. It will sit all night and start up clean in the morning, but if I let it sit a few hours it will smoke (but, again, not all the time). It's bluish, white smoke that does not smell like oil.

I took a 200 mile trip today with my step son behind me. He let me know that the thing was smoking really bad at random. I watched it and it turns out it's the transition from V4 mode to V8 mode. But at random. An easy, light throttle transition is okay. But if it goes to V4 and I need to suddenly switch to V8 it would billow smoke. It got better as the trip went on, but obviously there's an issue somewhere. Oil consumption isn't any worse than it's always been since I got it with 80k miles on it.

I did get a TPS error a couple of months ago but after clearing it a few times with a code scanner it hasn't come back.

Any ideas?
 
Keep track of your oil usage, but it sounds like the old PCV valve problem with some gen 2 GM has redesigned the valve cover.
 
Apparently the mere act of ordering the parts fixes it. No sooner did I order the revised valve cover did it stop smoking. BUT, it was down a couple of courts (low oil message came on) and I put some 10W-40 in it (all I had - but it's summer time so it should be okay). I think the heavier oil was just enough to stop the blow by.

The new valve cover and 8 new plugs came in via UPS today. I'll get to the swap over the weekend.

I may also disable the AFM.
 
Installed the revised valve cover today. It's pretty easy. As suspected, the valve cover that was on it was the old style.

I also changed all the plugs. They looked consistently crappy - nothing alarming, just the 140k originals. No sign of oil fouling or anything else. The TSB for the oil burning says #1 and #7 can foul but I didn't see anything like that.

It does idle much nicer now and seems to have more pep. Time will tell if it solved the oil consumption problem.
 
Where did you get the revised valve cover from? I have an '05 that does the same thing at random and goes through oil. I assume we are referring to the no orifice pcv problem?
 
plips_2002 said:
Where did you get the revised valve cover from? I have an '05 that does the same thing at random and goes through oil. I assume we are referring to the no orifice pcv problem?

I got the valve cover from gmpartsdirect. The new valve cover relocates the pickup for the PCV. I think it's an '07+ thing.
 
I have a 2005 with 118k on her and I have the same complain. Just started this fall, I cleaned the PCV rube with carb cleaner and changed my oil. It helped but Im going to do the valve cover this spring. ( had surgery on my wrist from a work injury so I can not move my fingers or wrist.)  Also running 10w30 oil to help with splash
 
Thanks for the info, I'll look into that different valve cover. Of course my engine calls for 5w-30, is it ok to run 10w-30 instead?
 
5W-30 oil has a viscosity of 5 centistokes (cs) in Winter temperatures and 30 cs in hot temperatures, so in the warmer months you have not changed anything by using 10W-30 vs 5W-30 oil.  I have also read that using the next high viscosity oil is acceptable after approx. 75K on your kilometerteller (odometer).

You should be fine.
 
Captain said:
Also running 10w30 oil to help with splash

This isn't going to help w/ "splash" once the engine is up to temp. A 5w30 oil and a 10w30 will perform exactly the same once warm. The number prior to the W is the viscosity of the oil in winter conditions, less then 10 degrees C. (50 degrees F). Once the oil hits 30 C (80 F). The viscosity is 30. In temps between 10 and 30 C the viscosity is variable, so running 10w30 vs 5w30 only splash less when the oil temp is less than 30 C
 
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