2009 GMC C1500 White smoke

REDNECK BOY

MEMBER
2009 GMC C1500
V8
4WD
AUTOMATIC
7,700 MILES

Hopefully you guys can help. Nobody seems to know.
My 2009 Sierra with only 7700 km's on it, (that's right 7700 km's) started emitting white smoke from the tail pipe. Both the service manager and shop foreman witnessed this at the dealership. My friends tell me I'm probably losing coolant The dealer had it for a week and cannot diagnose the problem. They claim no loss of fluids. They have done a pressure test and a compression test and cannot find a problem. They told me to take my truck back and to monitor the "oil" consumption. Now that I have the truck back, the white smoke problem seems to have disappeared, but I am left with sluggish performance. On top of getting only 450 km's to a tank on the highway, the truck now drives differently and feels under powered. It does not have the power one would expect from a 6 liter engine.

1 Reply

BLUELIGHTNIN6

MECHANIC
16,542 POSTS

Hello and thanks for donating

With sluggish performance usually comes the check engine light with trouble codes. Is the engine light on, if so what code(s) are stored? A leak doesn't fix itself, and white smoke usually means coolant/water leaking. Was the white smoke only at start up or the entire drive? If at start up, it could have just been water sitting in exhaust being burnt out at start up. Check your coolant level as well. If this truly was a leak and the coolant burnt out then your engine may have overheated, resulting in the now low performance and also explains why the smoke is no longer there, no coolant left in system = no smoke left to come out.