97 Conti w/ minor issues

[deaconlew]

I have just recently purchased a '97 Conti. When I got it the previous owner told me that he was not sure why the car would sometime overheat. It seems to be escallated when the A/C is running. The cooling fans work just fine. I have noticed that if the tempature is in the 80's (which in Texas is not very often) or if it is raining the A/C can run without the car overheating. Additionally, the heater works sometimes and at other times it does not. He has had the heater core replaced at a local F/L/M dealer to no avail. I am mechanically inclined and have worked on all my cars in the past. Here are my questions:
1. What *could* be cause of the overheating, and why?
2. Where is the thermostat on this vehicle? (4.6 V8 front wheel drive)
3. Why would the car overheat more rapidly if the A/C is running?
4. What are the chances that it could be a water pump problem, and what is the cost associated with replacing it?


Thanks
Deac
=========
1997 Lincoln Continental
Champaign Color
Tan Leather
Premium Wheels
4.6 V8
Sun/Moon Roof
No Mods

 

[Pepsi2185]

For the AC, any car is run harder with the AC on. It is a direct load on the engine and will heat the engine regardless.

I think i would shy away from the water pump as the problem, if the water pump is bad, you would get a chatter out of the shaft or leaking from the pump.

AS for the termostat, i would have to compare it to the rear wheel driver 4.6 in the TC. From the top hose of the radiator where it enters the engine usually the thermostat is under there, the conti guys can reaffirm this one.

How do you know it is overheating, are you getting a light, or gauge? It could also be a sensor.

If the car is genuinely overheating, i would suspect the thermostat. Have the system flushed completely and change your thermostat.

But you said the heater core doesnt work??? That could be the shut off between the engine and the heater core. IF the blender door actuator is moving the blender door, i would put my vote on the heater core shutoff.

 

[deaconlew]

How do you know it is overheating, are you getting a light, or gauge? It could also be a sensor.

I have a gauge. It stays within the letters n-o-r-m-a-l so long as the A/C is off and, I just noticed today, do not drive "racey" with it. This is a strange issue.

But you said the heater core doesnt work??? That could be the shut off between the engine and the heater core. IF the blender door actuator is moving the blender door, i would put my vote on the heater core shutoff.

No the heater core is working. I just realized that I had posted a previous message in another thread. I followed the steps that he mentioned, although I realize that I missed one important step. I tested the heater again last night and it worked just fine.

I agree that it may be a sensor. But I cannot find a way to confirm it. Would still like to know where the t-stat is so I can at least replace it. O'Reiley's sells them for $9. Inexpensive part, the question is where does it go.

Concerning the routing of the hoses, this car does not have a typical radiator. Coolant is put in from the metal tubes on top. There are three hoses and without a schematic I am unsure of the which is send or return making it dificult to perform a flush of the ssytem.

Other than this it is a great vehicle with lots of passing power. Currently all stock.

Thanks -Deac

 

[deaconlew]

I have driven it pretty hard this weekend. I noticed that the tempature rose out of the letters n o r m while still normal, but never got hot. In fact when it got to the point where it should have gone on to hot, it the hand went back to n o r m. This was with the A/C running. This morning it never went out of the letters n o r m. I drove it harder this morning during my comute to work that I ever have and it never rose out of the afore mentioned letters.
The tempature was 68 degrees when I left home and was 75 by the time I got to the office (my comute is 54 miles one way). So it did much better today so far. I will keep you posted.

 

[Pepsi2185]

Did you have the temp sensor replaced yet??? If the sensor is off, and the fans engage on the sensor, its resistance could be off by a bit. I believe there is one temp sensor on that motor. Other than that i am still thinking thermostat, but so far it seems like a temp sensor issue because it is intermittent.

 

[deaconlew]

I will replace the sensor this weekend (10/2/04). I will let you (everyone) know the outcome. -deaconlwe