Corsica 3.1L - Overheating

[bszopi]

If the fans are cycling on and off, then I would look into replacing the sensor. The temp sensor in the rear head is only for the guage, so it doesn't affect how the car operates. The one at the thermostat housing should be the one of concern. And if the fans are cycling, then the temp seen by the ECM is fine and the engine isn't overheating.

[ITR000]

If the fans are cycling on and off, then I would look into replacing the sensor. The temp sensor in the rear head is only for the guage, so it doesn't affect how the car operates. The one at the thermostat housing should be the one of concern. And if the fans are cycling, then the temp seen by the ECM is fine and the engine isn't overheating.

I replaced the CTC (Coolant Temp Sensor - Located below T-Stat Housing) when I changed the rad, upper / lower hosed and T-Stat. The fan does cycle on / off, when the the temp hits 95 (Temp taking with infrared temp gun at t-stat housing) then fan cycles on. After the fan cycles off, the temp on the housing is 85. I haven't owned a car with a GM 3.1 V6, but it seems the fan is coming on too late... Am I wrong?

[bszopi]

This is for a 3100, but it should be about the same:

Each Coolant Fan is turned on and off by a separate Coolant Fan Relay. The Primary Coolant Fan Relay coil is grounded by the Powertrain Control Module (PCM) when vehicle speed is less than a speed determined by the PCM and the Engine coolant reaches 1O8°C (227°F) with A/C off or 1O6°C (223°F) with A/C on. The relay contacts close and voltage is applied through the Primary Coolant Fan Relay to the Primary Coolant Fan. The Primary Coolant Fan runs until the Ignition Switch is turned "OFF," or Engine coolant temperature decreases to 1O4°C (22O°F) with A/C off, or 1O2°C (216°F) with A/C on.

The Pusher Coolant Fan Relay coil is grounded by the PCM when the Engine coolant temperature reaches 118°C (245°F). The relay contacts close and voltage is applied to the Pusher Coolant Fan. The fan then runs at high speed and will continue to run at high speed with the Ignition in "RUN" until the Engine coolant temperature lowers to 114°C (238°F).

[ITR000]

This is for a 3100, but it should be about the same:

Each Coolant Fan is turned on and off by a separate Coolant Fan Relay. The Primary Coolant Fan Relay coil is grounded by the Powertrain Control Module (PCM) when vehicle speed is less than a speed determined by the PCM and the Engine coolant reaches 1O8°C (227°F) with A/C off or 1O6°C (223°F) with A/C on. The relay contacts close and voltage is applied through the Primary Coolant Fan Relay to the Primary Coolant Fan. The Primary Coolant Fan runs until the Ignition Switch is turned "OFF," or Engine coolant temperature decreases to 1O4°C (22O°F) with A/C off, or 1O2°C (216°F) with A/C on.

The Pusher Coolant Fan Relay coil is grounded by the PCM when the Engine coolant temperature reaches 118°C (245°F). The relay contacts close and voltage is applied to the Pusher Coolant Fan. The fan then runs at high speed and will continue to run at high speed with the Ignition in "RUN" until the Engine coolant temperature lowers to 114°C (238°F).

hmmm. The car has AC however, the engine bay does not have a seprate fan for the AC system. There is only one large fan connected as per usual directly to the rad housing. However, if the temps are the same for 3.1 as they are for the 3100, the fan is cycling at the correct temps - 108 / 102 respectivly.

Not sure, as mentioned, I will do a pressure check and if all is fine, I will replace the sensor on the head which sends signal to the dash guage.

Also, as part of the pressure check, I am going to remove each plug and check for signs of coolant leak in the cylinders.

I will post my finds.

[854x4s15]

The corsica is not a bad car. The most problematic things are exterior door handles changed allfour and passengers side twice. As well as an ongoing heater issue. Little or no air flow. The 3.1 is a very reliable engine. Mine's a '93. They were made from 1986-1996 the only changes to the appearance was an updated interior and dash in 1991. Be glad you did'nt buy one with one of those 2.2L four bangers.

Have you checked your water pump? It may be getting ready to take a crap.

[ITR000]

The corsica is not a bad car. The most problematic things are exterior door handles changed allfour and passengers side twice. As well as an ongoing heater issue. Little or no air flow. The 3.1 is a very reliable engine. Mine's a '93. They were made from 1986-1996 the only changes to the appearance was an updated interior and dash in 1991. Be glad you did'nt buy one with one of those 2.2L four bangers.

Have you checked your water pump? It may be getting ready to take a crap.

Thanks. How do I check the water pump? It doesn't make any sounds which would indicate a bearing issue and of course I have no coolant leaks. How I check if its flowing enough coolant?

[Shadyman]

Sorry to offlink, but hey

Recently, I have been getting several PMs as well as seeing many posts on the board about the temp gauge going up to 3/4s on people's Corsica V6s. This IS completely normal as long as the fan turns on around 3/4s and brings the gauge back down somewhere between 1/2 and 3/4s. On most cars this is dangerous, but NOT on Corsica V6s. Once again it is completely normal as long as no idoit lights come on. If a idoit light does come on (which all Corsica V6s have) then the vehicle is overheating or another problem could be occuring. The most common problem is the fan relay, an easy fix. The way to check to see if the fan is working is to turn on the A/C. The fan should come on when the A/C is on, or when vehicle is in diagnostic mode.

http://www.corsicas.com/forums/index.php?showtopic=6379

This whole discussion has been discussed already, more or less Enjoy

Also,

They were made from 1986-1996

1987-1996, Though I've never seen a 1987, i'm told they exist.

[ITR000]

Sorry to offlink, but hey

Recently, I have been getting several PMs as well as seeing many posts on the board about the temp gauge going up to 3/4s on people's Corsica V6s. This IS completely normal as long as the fan turns on around 3/4s and brings the gauge back down somewhere between 1/2 and 3/4s. On most cars this is dangerous, but NOT on Corsica V6s. Once again it is completely normal as long as no idoit lights come on. If a idoit light does come on (which all Corsica V6s have) then the vehicle is overheating or another problem could be occuring. The most common problem is the fan relay, an easy fix. The way to check to see if the fan is working is to turn on the A/C. The fan should come on when the A/C is on, or when vehicle is in diagnostic mode.

http://www.corsicas.com/forums/index.php?showtopic=6379

This whole discussion has been discussed already, more or less Enjoy

Also,

They were made from 1986-1996

1987-1996, Though I've never seen a 1987, i'm told they exist.

I know, I am ITR000 and the last post on that corsicas.com's thread is mine.

[SappySE107]

wow, i wasn't even aware that there was corsicas.com. Guess ill check that out:P Poor beretta.net, no one likes you anymore

[n0rt0npr0]

water pump check

Thanks. How do I check the water pump? It doesn't make any sounds which would indicate a bearing issue and of course I have no coolant leaks. How I check if its flowing enough coolant?

Correct me if I am wrong, but to check whether the water pump is working wouldn't you:
-start engine
-let the engine warm up to where you feel the upper hose is warming up(or maybe till temp gauge is sitting past where its suposed to)
-then grab the lower hose and feel for surging

That surging is the pump working.
~Will

[Carlspike]

Does your car idle at the correct speed? I have a 3.1 that was running a little hot because of an increased idle, I corrected it and now my gauge sits at about 1/4 all of the time.

[Juglenaut]

RE: water pump check

The sensor in the head is an engine temp sender, the sensor in the t-stat housing is the coolant temp sender. If the gauge hits red you are overheating. The gauge pulls its referance from the t-stat located sender not the head, that is where the ECM pulls its referance. Typically a T-stat will start to open at 195 degrees, fully open may be close to 215 degrees or slightly higher. Fans will turn on at about 220ish degrees. This allows the coolant to pool heat in the radiator then kick the fans, allowing for a more linear cooling.

If you are worried about it then get a different t-stat. If your water pump is not working you will know it, the engine will more than just over heat. Water pump tend to squeel really bad just before they go bad, they will work fine upto the point of breaking the shaft, there is no in between either it works or it is broke.