No Heat and Low Engine Temp

[JoshFFuller]

I have a Grand Am SE 2001 and recently, since I got home from college for break, there has been no noticeable heat, and the engine temperature gauge is reading below 100. I checked the heat of the input and output hoses near the firewall and both were warm (warmer than the air blowing in the car) but not hot to the touch and this was after 10 minutes of driving 40 mph. Right now my only ideas are the thermostat or the heating core, could anyone suggest what to look for? I'm not sure, short of replacing both, how to progress. Alos wondering if driving it in this state is bad for the vechicle, I can't seem to find anything wrong with the engine and all other parts are working fine, not much chance to fix it for a few days.

[aleekat]

If you engine is running cold, then suspect failed thermostadt stuck open. Lot easier fix than fooling with the heater core for right now.

[JoshFFuller]

Originally Posted by aleekat

If you engine is running cold, then suspect failed thermostadt stuck open. Lot easier fix than fooling with the heater core for right now.

Great, thank you! I'll pick one up tonight and pop it in tomorrow. I'll let you know if it works.

[Tech II]

Thermostats don't pop in on these cars....3.1/3.4 or 2.2/2.4? Coolant level ok(checked on a cold engine)?

[JoshFFuller]

Originally Posted by Tech II

Thermostats don't pop in on these cars....3.1/3.4 or 2.2/2.4? Coolant level ok(checked on a cold engine)?

2.2, I've dealt with thermostats on a couple of fords before, not familiar with the lay out for Grand Ams (the car is still rather new to me) any tips or points would be great.


Also, I was driving my girlfriend home from work today, with the heat off, and I thought I would try the heat when I dropped her home, heat worked perfect for about 30 seconds then got colder until it was about 50 degrees F (it was around 30 degrees out) I'm wondering if this points to a heating system error, or if it is still the thermometer? All I can figure is it blasted the heat, then it got mixed with coolant as it ran the heat, indicating maybe the temperature control isn't working right? I had it on heat all the way to the right (full heat) for the temp control and fan at 5, all I got was cool air the longer it ran.

[thephantom1492]

My check list would be:
- coolant level in expension tank
- After driving for a bit, check the engine temperature. If the gauge say it's cold, and the engine temperature about match what the gauge say, I'ld assume that the gauge work fine
- Does the cooling fan turn on when cold? (beware of the A/C setting, which may be on at recirculation (max) and defroster, so might want to turn off the heat/blower. If it turn on, it might be the issue, investigate why it turn on when cold.
- Radiator hose, Are they matching the engine temperature?
- Thermostat might be faulty. They are normally designed to fail open.

Personally, I'ld suspect the thermostat. Else you have a multiple failure (temp gauge/sensor AND the heat selector thing (I'm unsure if it's a valve or a blend/mix door actuator (motor) that control the cold/heat on that car)

Water pump would cause engine overheating in no time, so the gauge would be quite high.

[JoshFFuller]

Originally Posted by thephantom1492

My check list would be:
- coolant level in expension tank
- After driving for a bit, check the engine temperature. If the gauge say it's cold, and the engine temperature about match what the gauge say, I'ld assume that the gauge work fine
- Does the cooling fan turn on when cold? (beware of the A/C setting, which may be on at recirculation (max) and defroster, so might want to turn off the heat/blower. If it turn on, it might be the issue, investigate why it turn on when cold.
- Radiator hose, Are they matching the engine temperature?
- Thermostat might be faulty. They are normally designed to fail open.

Personally, I'ld suspect the thermostat. Else you have a multiple failure (temp gauge/sensor AND the heat selector thing (I'm unsure if it's a valve or a blend/mix door actuator (motor) that control the cold/heat on that car)

Water pump would cause engine overheating in no time, so the gauge would be quite high.

had coolant fixed a few months ago, had a leak (loose bolt) and they topped it off and flushed it, both radiator hoses are warm but not hot, about 80 degrees it feels like. The engine is too hot to touch, with my hand a few inches from it I can feel the heat, I am almost certain it is the thermostat, been bad weather here so i haven't had a chance to go out and get one yet.

Could anyone supply me with a simple diagram or explination of where it is on a Pontiac?

[xeroinfinity]

Originally Posted by JoshFFuller

had coolant fixed a few months ago, had a leak (loose bolt) and they topped it off and flushed it, both radiator hoses are warm but not hot, about 80 degrees it feels like. The engine is too hot to touch, with my hand a few inches from it I can feel the heat, I am almost certain it is the thermostat, been bad weather here so i haven't had a chance to go out and get one yet.

Could anyone supply me with a simple diagram or explination of where it is on a Pontiac?

Welcome to AF JoshFFuller!!
If your coolant level is correct, then it does sound like your thermostats stuck open. A pain in the ass on this motor!

Try this link for the procedure!

If this doesnt help, it could be your heater core clogged from the flushing...more fun then a bag of snakes to change. Good luck!