What's wrong with my cooling system?

2003 PONTIAC GRAND AM
297,000 MILES
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
Ok, the car started pushing coolant out of the overflow. Also boiling in the rad. Coolant seemed to be circulating so not the water pump. No coolant in the oil and no oil in the coolant and no white smoke. Not the head gasket. So, Had a mechanic replace the thermostat. He has 30 yrs experience so not backwards. Car is still overheating but not pushing out coolant. What's the problem? Car is an 03 grand am gt.
Jun 7, 2012 at 7:06 PM
Advertisement
Avatar
DOCFIXIT
  • CERTIFIED EXPERT
  • 18,828 POSTS
cooling fans operating?
Jun 7, 2012 at 7:08 PM
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
Yes, fans are working. It's got the 3.4 as well. This really has me confused. I'm thinking maybe blockage but I'm not sure. Everything seems to be doing what its supposed to but it just overheats. Oh..and from cold, it heats up quickly.
Jun 7, 2012 at 7:14 PM
Advertisement
Avatar
DOCFIXIT
  • CERTIFIED EXPERT
  • 18,828 POSTS
suspect radiator blockage when hot feel radiator any cool spots?
Jun 7, 2012 at 7:17 PM
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
yes. blowing cold air.
Jun 7, 2012 at 7:18 PM
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
oops misread the reply. haven't really felt the rad but last night when it overheated all the supports on top seemed cold.
Jun 7, 2012 at 7:20 PM
Avatar
DOCFIXIT
  • CERTIFIED EXPERT
  • 18,828 POSTS
Does top hose get hard and feel hot? hjas radiator cap been tested to hold pressure? bottom hosewarm and not collapsed?
Jun 7, 2012 at 7:42 PM
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
No, top hose is not really hot or hard. Rad cap seems ok. may try a new one. not sure about bottom hose.
Jun 7, 2012 at 8:58 PM
Avatar
DOCFIXIT
  • CERTIFIED EXPERT
  • 18,828 POSTS
Was Air bleed valve opened when filling?
Jun 7, 2012 at 9:02 PM
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
no. could it be so simple as air lock?
Jun 7, 2012 at 10:18 PM
Avatar
DOCFIXIT
  • CERTIFIED EXPERT
  • 18,828 POSTS
yes if air bleed valve was not opened
Jun 8, 2012 at 2:15 PM
Avatar
FATHOM
  • MEMBER
  • 7 POSTS
a new wrinkle that leads me to believe it could be airlock. while driving to work last night, instead of taking all the straight roads, I also took a road full of turns. The engine was getting hot but as I hit the turns, it cooled down some. does this tell you, as a mechanic, anything?
Jun 8, 2012 at 8:01 PM
Avatar
DOCFIXIT
  • CERTIFIED EXPERT
  • 18,828 POSTS
well maybe move to W.V.
Jun 8, 2012 at 8:25 PM