Smoke at start up
 

Hey I was wondering if anyone can tell me what could be causing my Yukon to blow out a huge cloud of a white/blueish color smoke from my exhaust when I first start up in the morning. After that it doesn't happen the rest of the day. This just started on Friday, I do have 202,000 miles,

Re: Smoke at start up
 

white is coolant.
blue is oil.


Look for a reduction in levels of both. Check cold every morning.


I would suspect weeping head gasket for coolant and valve guide seals for oil.

Re: Smoke at start up
 

What am I looking at cost if it is those two things, is worth the fix if the truck has over 200,000 miles?

Re: Smoke at start up
 

No idea beyond "not cheap"

Re: Smoke at start up
 

Sounds like classic Valve Stem Seals to me. Been a Small Block Chevy "feature" for decades.


If it is you should have measurable oil consumption. So how far on a quart?


Like S Keith said, is coolant disappearing?


If it is stem seals, the Catalytic converter is NOT hot on the first start of the day.





Also, if it is Stem Seals, it's relatively CHEAP. Shop air into the spark plug hole and an over-head valve spring compressor

All subsequent starts a hot Cat masks a multitude of sins.


We had a suburban race boat hauler that would fog real good at the motel in the morning. The rest of the time towing no smoke at all.


Only the morning fog.

Re: Smoke at start up
 

My engine would blow a slight puff of smoke on cold start as well, turned out I had no(low) compression on 2 of my AFM cylinders. Do a compression check on your engine I would suspect oil fouling as it is a common problem with these AFM engines.

Re: Smoke at start up
 

Valve stem seals all the way on a Blue Smoke cold startup. Indicates that other areas of the engine also probably have substantial wear.
Drop in a new crate engine and make sure you only run synthetic and change oil at 50% OLM and you should get another 300k out of your rig easy.
Haha it is easy for me to Spend OPM (Other Peoples Money) just messin with U. I would just drive it until it starts fouling plugs then have the heads pulled off and rebuilt.
The Blue Smoke works great in the summertime as a gnat smoke. Do you have yuppie neighbors that will be offended by your tailpipe smoke?