Alero Overheating

[cubanreuben]

Ok, so I just got my car back from the dealership 3 days ago. The car worked great, and the problem hasn't shown itself. I was driving to my parents (a 2 hr. drive on the interstate) and it was getting dark. My lights turn on, and I realize that it's awfully dark in my car. Turns out, the dash lights were working fine, but the lights that illuminate the console are not working. My guess is that someone unhooked something when they replaced my ignition switch, so I planned on calling the dealership I had it service at to tell them to fix it. Well, I drove some more, and some screws fell out of my dash. Now, this scared me! So, I made a mental note to call them ASAP the next day. Mechanically, the car worked great.

So, on my return trip to my house, everything is going great...that is until I reach the city. When I get there, my car overheats for NO reason. I just see the temperature gauge going up. I pull over, and instinctivily turn on the heater, and turn off all other accessories to the car. At this point, the needle is at 3/4 the way to the overheating mark. With the car still running, I get out to check things out under the hood. The coolant level is ok. I don't here any wierd noises (at least those sounding like a water pump could be going out), but I do notice that the radiator fans are barely turning. I would figure that if the car were extremely hot, the fans would be turning. I thought to myself that it could be the temperature guage since the fans weren't running. But I also notice that it feels hotter than normal under the hood. I get back in the car, and shut it off. I let it sit for a minute, and then start it back up. The temperature guage is still high, but as soon as I turn it on, both fans turn on, and are pushing a lot of air out, and I can feel the HEAT! So, what's the problem here??? I took it to the dealership today, and they're fixing the loose screws and the dash lights. They too noticed my temperature guage, and they recommended that they look at that too. Being frustrated, I told them to, and they gave me a ride home.

Are there fan relays in this car??? Could that be the problem?

Thanks, in advance, for your help... Hopefully, I just won't keep asking questions!

[cubanreuben]

Originally Posted by bnaylor

The fan system includes the following components:

* Two (2) electric cooling fans (Left & Right)
* Three (3) fan relays (COOL FAN 1, COOL FAN & COOL FAN 2)
* Two (2) fuses (30 Amp Maxi fuses #6 [COOL FAN 1] & #1 [COOL FAN 2])
* All associated wiring & connectors

There are three basic modes for the fans: OFF, Low-Speed, and High-Speed. These modes are controlled by the Powertrain Control Module (PCM).

Fans OFF:

* When the coolant temperature is less than about 220°F (104°C) or
* The A/C refrigerant pressure is less than 190 psi (A/C off).

Low-Speed:

* When the coolant temperature is between about 220°F (104°C) and 230°F (110°C) or
* The A/C refrigerant pressure is more than 190 psi (1310 kPa) or
* When car is turned off and the coolant temp is more than about 284°F (140°C) and system voltage is more than 12 Volts. Fans will run for about 3 minutes.

High-Speed:

* When the coolant temperature is above about 230°F (110°C) or
* The A/C refrigerant pressure is more than 240 psi (1655 kPa) or
* When certain DTCs are set.

Other information:

* The thermostat for these cars normally opens at about 195°F (93°C)
* The "Engine Coolant Temperature" message should appear (on dash) if the engine coolant temperature is above about 262°F (128°C). PCM sends a message to the Instrument Panel indicating temperature.
* The "Engine Coolant Level" indicator should appear (on dash) if the coolant level goes below a certain level.

Ok, I took the above information from another post. (Hope it's quoted correctly...) I was just going to tell you that I did notice that when the car was off, the fans were still running. So, the above post says that the fans will run on low if the temperature of the coolant is above 284°F... Isn't that a little warm???

[BNaylor]

Originally Posted by cubanreuben

Ok, I took the above information from another post. (Hope it's quoted correctly...) I was just going to tell you that I did notice that when the car was off, the fans were still running. So, the above post says that the fans will run on low if the temperature of the coolant is above 284°F... Isn't that a little warm???

Low-Speed:

* When the coolant temperature is between about 220°F (104°C) and 230°F (110°C) or
* The A/C refrigerant pressure is more than 190 psi (1310 kPa) or
* When car is turned off and the coolant temp is more than about 284°F (140°C) and system voltage is more than 12 Volts. Fans will run for about 3 minutes.

I believe you have misinterpreted. In normal conditions the cooling fans will turn on in low speed when the car is running and engine temperature is in a range of 220 - 230 degrees F. Also, the cooling fans almost always turn on when the A/C is on.

The last part is only when ignition is off and the temperature ever gets that high to include battery supply must be at least 12 volts or more. Just a safety feature but I have never seen this scenario ever occur. If your engine temperature ever gets that high then there is a big problem like a stuck thermostat, bad water pump or possibly head/intake gaskets.

If your fans are running with the ignition to off and the temperature is not that high then you probably have another problem. Possibly either ECT sensor or the PCM module.

[cubanreuben]

Originally Posted by bnaylor

I believe you have misinterpreted. In normal conditions the cooling fans will turn on in low speed when the car is running and engine temperature is in a range of 220 - 230 degrees F. Also, the cooling fans almost always turn on when the A/C is on.

The last part is only when ignition is off and the temperature ever gets that high to include battery supply must be at least 12 volts or more. Just a safety feature but I have never seen this scenario ever occur. If your engine temperature ever gets that high then there is a big problem like a stuck thermostat, bad water pump or possibly head/intake gaskets.

If your fans are running with the ignition to off and the temperature is not that high then you probably have another problem. Possibly either ECT sensor or the PCM module.

Thanks for your help. The fans were running with the ignition off, and the temperature was above the mid-mark on the thermostat. The dealer is still diagnosing the problem. Thanks for your help, bnaylor! I'll post when I know something... Also, just wondering. How much am I looking at for the above mentioned problems??? Thanks again!

[cubanreuben]

Originally Posted by cubanreuben

Thanks for your help. The fans were running with the ignition off, and the temperature was above the mid-mark on the thermostat. The dealer is still diagnosing the problem. Thanks for your help, bnaylor! I'll post when I know something... Also, just wondering. How much am I looking at for the above mentioned problems??? Thanks again!

Just to let everyone know, they couldn't get my car to reproduce the problem. After frustrated attempts to speak with the manager, he agreed that if I came in and the car had the same problem, he'd credit my repair bill with the bill I paid today (diagnostics that came up negative). He understood that I was mad that they didn't plug the car up to the computer while it was overheating, even though I told them it was an intermittent problem. Apparently, they said the temperature never got above 190F. But then again, they didn't go out and drive it, and the only load they put on it was the air conditioner. Shouldn't these guys know that the fan will run with the AC compressor is on??? Because I was having a problem with the fans when the AC was off. I told the dealer as much, and they just told me to take it back in when it was overheating... That's real convenient!

Thanks for all your help guys.