help! white smoke all of a sudden this morning...

[knoslf]

Got up this morning and started my 99 Yukon SLT 5.7 Vortec and all of a sudden tons of white smoke was coming from the tailpipe, it was the first start after sitting all night and it's been running fine all week. I must say though, yesterday i was VERY low on coolant and the overflow container was empty so I added some coolant to the radiator and overflow, and also replaced the cap with an aftermarket one from O'Riellys. I did ad the green stuff because thats what was in there so i assumed the previous owner flushed the Dex-cool out and used the green stuff. But why is all this white smoke blowing out? Just changed the oil a couple mos ago and the it hasnt begun to burn any nor is there any signs of water on the dip stick, its just the white smoke, no water coming out just smoke...what should I do? Could that radiator cap be a problem? The new one is a little $5 metal one and its smaller but the oe cap is a bigger black plastic one. Also, i drove about 20mi after adding coolant/cap yesterday with no problems, just started this morning.

 

[Phone Man]

That is a sure sign of a coolant leek from either the head gasket or the intake gaskets. The smoke will also smell funny like burning antifreeze if that makes any sense.

 

[SunlitComet]

you just figured out your own problem. and the cap does not let water into the cylinders.

 

[knoslf]

Thanks guys! Just drove it for about 45mins and it never stopped smoking, didnt even a little less, took that new radiator off and put the old one back on and BAM!...it stopped smoking and after about 15-20 more miles of driving it didn't start smoking again...so, i keep my fingers crossed that it doesnt happen in the morning when i go to work, thanks again fellas!

 

[Trippers99hoe]

Thanks guys! Just drove it for about 45mins and it never stopped smoking, didnt even a little less, took that new radiator off and put the old one back on and BAM!...it stopped smoking and after about 15-20 more miles of driving it didn't start smoking again...so, i keep my fingers crossed that it doesnt happen in the morning when i go to work, thanks again fellas!

Get a pressure test done on your cooling system,If a radiator cap caused an internal coolant leak(intake gasket,head gasket etc.) you have a problem that could cost you an engine.

Intake gaskets are a known problem on the vortec engines.

 

[knoslf]

Get a pressure test done on your cooling system,If a radiator cap caused an internal coolant leak(intake gasket,head gasket etc.) you have a problem that could cost you an engine.

Intake gaskets are a known problem on the vortec engines.

Well, i guess a pressure test is in order, just went out to go to the store and guess what, the smoke has returned, its in the 90s here in the Denver area and im kinda fed up so I'll get on it tomorrow, wonder if the radiator cap was the problem can the store be held responsible....jus sayin. btw, I havnt lost any coolant from the radiator, but the overflow is empty as it's always been.

 

[Trippers99hoe]

Well, i guess a pressure test is in order, just went out to go to the store and guess what, the smoke has returned, its in the 90s here in the Denver area and im kinda fed up so I'll get on it tomorrow, wonder if the radiator cap was the problem can the store be held responsible....jus sayin. btw, I havnt lost any coolant from the radiator, but the overflow is empty as it's always been.

How many miles,have the intake gaskets been replaced....Just my opinion but you really shouldn't drive(run) the engine until you fix whatever is causing the problem....if you get water in the oil you can go from a couple hundred dollar repair to a couple thousand.

 

[knoslf]

How many miles,have the intake gaskets been replaced....Just my opinion but you really shouldn't drive(run) the engine until you fix whatever is causing the problem....if you get water in the oil you can go from a couple hundred dollar repair to a couple thousand.

Dont know about the intake gaskets have been changed but it does have 245k miles on it. Welp, after researching ect ect, I am now debating weather or not i want to drop another Vortec in it or what, Its not the prettiest Yukon, but I love my truck lol, found this on CL... http://denver.craigslist.org/pts/3096582336.html
for $750 and this is a serious thought. I already considered getting another truck but i already 'know' my truck and wasnt really trying to start over, at least with a used one I can mod before its installed rite lol...what do you think?

 

[knoslf]

is their an additive to stop the smoke? Its kind've embarrassing lol

 

[ChrisAU]

Stop driving it! You can do intake gaskets (best case scenario) for $300-$500, head gaskets (almost worse scenario) for $500-$700, or you can ruin the engine (worst case scenario) if you keep driving it and be looking at $1500-$2500.

Those prices are with a shop doing the work by the way.