1999 Chevy Suburban Overheating and smoke coming from vents

1999 CHEVROLET SUBURBAN
211,000 MILES • V8 • 4WD • AUTOMATIC
Avatar
SUBURBAN91
  • MEMBER
  • 1 POST
I have a 1999 Chevy Suburban with 211000 miles on it and just recently it started overheating very quickly (within minutes of driving it). I replaced the thermostat and it is still overheating. I added more coolant to it and was running it for about 20-30 minutes with heaters on high and smoke started coming from the inside dashboard vents and from under the hood. I don't see any leaks underneath the vehicle so what could it be??
Dec 18, 2009 at 1:15 PM
Advertisement
Avatar
MHPAUTOS
  • CERTIFIED EXPERT
  • 31,937 POSTS
HI there,

Thank you for the donation'

You will have to get a cooling system pressure test done, have it done hot and with the heaters on, this will locate any external coolant leaks, also i would suggest a cooling system Co test, this will pick up any traces of Co in the cooling system and if so this is a sure sine of a head or gasket problem, start here.

mark (mhpautos)
Dec 18, 2009 at 8:19 PM