95 Grand Am Overheating Problem Got Me Stumped

pontiac

#1

I have a 1995 grand am that after about 15 minutes or so, the temp gauge climbs past normal operating temp, and will bury itself into the red.



I’ve got no noticeable leak, there is no steam like you would get from an overheated car. The only noticeable thing besides the gauge, is that you can smell that the car is hot, you can smell the antifreeze. i do have to put coolant in it every few months so there does seem to be a small leak, or it’s just normal evaporation.



I’ve had it to the mechanic and it’s had a new air dam, thermostat, sensor.




#2

On a vehicle this old, it wouldn’t be uncommon for the radiator to be restricted causing the overheating.

Tester


#3

Can we assume that the fan is running continuously? I didn’t see that included under the checked off list of usual suspects.


#4

Check or just replace the radiator cap. If it does not seal correctly the coolant will boil away and the engine will start to overheat. Radiator caps are cheap, easy to replace, and can cause mysterious problems.


#5

i don’t think the fan kicks on immediately, but it does continue to run after the car is shut off until it cools back down.

i’ll check out the radiator cap, and didn’t even think about the restriction as a possible culprit.

it drives me nuts b/c the car runs good, but the temp gauge redlining w/o any of the normal steam or typically indicators that it’s overheating is puzzling to me. it’s a good thing i don’t have far to drive to get to work.


#6

start cold engine rad cap off, as engine warms and thermo opens, you should detect considerable motion of coolant. if not, thermo(even new)may be faulty, or waterpump impeller blades may be corroded away. if you have flow, radiator deposits may be culprit.
new air dam? bodywork i assume? also check lower radiator hose, if the internal metal spring has corroded, it can collapse when pump draws coolant from radiator. just give it a squeeze, if it’s all mushy and you feel no resistance, watch it (rad cap on) and you may see it collapse on it’s own.
good luck,keep yer fingers outa the fan.