Blows smoke out the exhaust pipe when started up

[Topman]

I have 2005 GMC Yukon SLT. My truck blows smoke out the exhaust pipe when started up. Why it does that. Any suggestions some one 

 

[txab]

Probably valve guide/ guide seals. Especially if high mileage. Color of smoke?

[Topman]

It’s white smoke. When my truck sits for a while and I starts it up it. White smoke comes out the exhaust pipe. 

[Topman]

It’s has 194,00 miles on it

[Topman]

When the truck sit for a period of time and I starts it up white smoke comes out and it clears up afterwards. It’s does not smoke while I’m driving it.

[CamGTP]

Has the coolant level in the expansion tank dropped at all?

 

Typically the color of smokes are blue for oil, black for extra fuel, white/grey for coolant.

[Topman]

Yes sometimes I have to add coolant. The truck does not burn oil

[CamGTP]

Well, looks like we've answered the question of why it smokes. If you have to add coolant, that means it's going somewhere and that somewhere is out the exhaust.

 

It's likely a slow head gasket leak. I would replace both at the same time. There is a very rare chance the a cylinder head is cracked, some trucks with the "castech" stamping had some issues with the heads cracking.

 

http://ww2.justanswer.com/uploads/Bluegorilla/2008-12-05_142924_Coolant_loss_5.3.pdf

[Topman]

O wow thanks for the information I will get my mechanic man too look at it.

[KARNUT]

O wow thanks for the information I will get my mechanic man too look at it.

At 194 miles depending on what you do with it I would consider stop leak or block sealer. This will buy time until you decide how far you want to go with it as far as money spent. I’ve seen sealer last the life of the engine. At 194K I would plan on a rebuild if the vehicles worth it. Otherwise the stop leak may do the trick.


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[Topman]

Ok that probably would save me some money. I’ll go by the part store. Do you know anything about rear axle seal leaks? GMC YUKON.

[KARNUT]

Ok that probably would save me some money. I’ll go by the part store. Do you know anything about rear axle seal leaks? GMC YUKON.

Look on line to see if it’s a job your comfortable doing. I wish I had that option when I started working on vehicles.


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