Running Hot

[rkuchar1]

I have a question about my car

1999 Pontiac Grand AM SE

3.4 L

Driving on the highway it runs normal.

Driving in the city it starts to over heat.

I have replaced the water pumper, thermostat.

[Jmoney3318]

over heat temperature is at what when driving in the city?

[Theessence]

I guess it depends by what you mean by "overheating". If you mean its just hotter then I believe that's normal.

Do you drive it harder or go WOT when you're in the city? The more often your rpms are high I can imagine the engine getting a lot hotter than cruisin at 2k rpms on highway.

[dlwdkh]

These cars are hard on radiators. Flush the engine good. Install new antifreeze and distilled water. If it still has problems and has more than 100k you should consider a radiator.

[xeroinfinity]

Usually when a car overheats in city when it doesnt on highways is a sign thiers flow issues.

Like dlwdkh said, flush your cooling system.

That should take care of the higher temps in the city.
If not then you could have a LIM gasket going bad.

Cooling fans run commands....

The PCM commands Low Speed Fans ON under the following conditions:

The engine coolant temperature exceeds approximately 106°C (223°F).
The A/C refrigerant pressure exceeds 1310 kPa (190 psi).
The vehicle is shut off when the engine coolant temperature is greater than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay ON for approximately 3 minutes.

The PCM commands High Speed Fans on under the following conditions:

The engine coolant temperature reaches 110°C (230°F).
The A/C refrigerant pressure exceeds 1655 kPa (240 psi).
When certain DTCs set.

[inafogg]

hello are the cooling fans working??

[rkuchar1]

Sorry about the delay. My Computer has been down and this is the first time I had a chance to reply.

It runs above 90 degrees then actually starts to overheat, going to red....
I wouyld say about 1 hr of driving will do this...Just city driving, basically @ 50km/h

[powermaster]

Have you verified cooling fans working?