Contour Enthusiasts Group Archives Forums General Troubleshooting Stuck on a "almost" overheating issue

Well I have complained a few times that my car, since it's purchuse, has slowly ran hotter and hotter. It normally ran in between the O and R. After about a year or so, it started running in between the R and M, visiting the O only during warm-up's. There was a few times that, out of the blue, the car would run between the N and O! But after a day or so, it would return to running between the R and M.

A few months ago, I replaced the thermostat, but that made no difference.

Yesterday, I noticed that the sensor was slowly climbing over to the far side of the M! I turned the heat on (yeah, it ain't that cold here during the day ) and it slowly worked it's way back down. I was planning to stop off at Autozone to get some ATF, so I went ahead and got a water pump too. It has been on my to-do list forever, just never did it.

I noticed on the way home that traveling down the road, really made no difference in the temp readings. It was running the heater that was saving my tail. I could hear my fans running at low-speed when coming to a stop and also could hear the fans kick into high once I was at a stop or just before. Still, it did not seem to make any difference! The temps would rise to the far side of the M, never quite making it to the A.

I changed my water pump this morning and found nothing wrong with it at all!! And it was one of the plastic one's too!! It was off white in color and not black, so that might have something to do with it. Anyway, 188K on that bad-boy!! WHOO HOO!! I went ahead and installed the metal impeller one anyway.

Anyway! Still no difference! Tonight, after reading some posts from a search - I went outside, let the car idle and just watched everything. The temps raised slowly to the farside of the M and the fans finally kicked in low speed. I felt the hoses several times and squeezed them. I could fell some pressure building (by the hoses getting stiffer) and I could also see the fluid in the coolant bottle move with each squeeze. Before starting the car, when doing this, I could also hear the check valve/bypass valve (whatever it is called) on the thermostat rattle. So I know that is not stuck. After a short while, the temp of the air exiting the fans was almost cool. I checked the temps inside and it was between the M and A! The cooling fans kicked into high and I cut the heater on. Within a minute or too the temps came down to between the R and M.

When pressing on the hoses, on both sides of the thermostat, the fluid in the coolant reservoir would move with each squeeze. Also, after shutting the car off, I was able to remove the reservoir cap with very little hiss and fluid inside was only lukewarm.

With all that, I am wondering if I am dealing with a partially stuck open thermostat or a leaking reservoir cap? Any suggestions???

Maybe the temperature sensor is going bad and reading high. Is the heater discharge air hotter than it used to be? If you have access to an infrared thermometer (Raytec or equivalent) check the actual temperature. You may not be hot, maybe the sensor is fading.

I would get a candy thermometer and poke it into res. after running the car. Also have you looked under the air dam to see if you rad. is full of bugs? Are the fins bent over in spots? Have you ever had the system flushed? Do you have hard water in your area? JRL

I had a similar situation with my 1996 Mystique 4cyl Auto Trans. During the summer of 2001 I first noticed my car running warmer than normal, somewhere between the "M" and the "A" on the gauge. Between then and last month I replaced the thermostat twice. The first time with the stock Motorcraft thermostat, the last time was this past September. By this time the Temp needle was past the "L" and kissing the maximum end of the band. I then installed cooler 180 degree thermostat. This helped a lot. The car was almost back to normal. I had also replaced the Temp
gauge sending sensor, in case I had an incorrect reading, I changed the ECT, in case the computer was getting incorrect Temp info and not turning the fan on and off properly. None of that helped. I also flushed the cooling system, no help. I removed all of the bugs and other debris as well as straightened the bent fins on the front of the A/C condenser in case air flow through the radiator was being restricted. No help

Finally!!! Last month I found the source of my overheating. I was driving with the pedal to floor (going to church, right) when all of a sudden I had no more forward power. My transmission had gone out. I had no forward, only reverse worked. I drove 2 miles backwards at night. My passengers were not as amused as I was. Anyway $2000 and a new transmission later my car no longer runs hot. In fact
because of the 180 degree thermostat it is running too cool. After a half hour of driving my needle is at the "N". During a long drive on the highway the needle is at the "O". That's where it used to be when I first got my car. I will be re-installing the stock thermostat to bring up the temp.

Oh, my transmission went out at 147,000 miles. I hope this helps some one. I know there are a lot of over-heaters out there.


1996 Mystique GS 4cyl Auto Trans.
148,000 Mi.

A little update on my issue here.

I finally got my cap in today and was able to get it on tonight. So far, it is perfect.

What I did find was this... I noticed that the center portion on the underside of the cap, where the seals are, it was loose. You could freely spin it and actually lift it a very small amount. My old one was frozen in place and would not move around at all.

So I figure that was it, becasue the temp gauge does not get above R even when sitting idle with the heat off.

If it still runs hotter than you'd like, get a cooler thermostat, I know it's not a true fix, but it works, I rarely see above O, most mornings it won't even get past N on my way to school.

i need a new thermostat on my 98 svt. Would u guys recommend i buy a direct replacement or a 180 degree one?

Had this problem with my 95 contour gl 2 years ago. The culprit was the cooling fan and some wiring. The wiring was burnt. Hope that helps a bit.

When I bought my 98 tour, 6 months ago, temp ran in the AL area tending to be in the L area. I had the antifreeze replaced and cooling system FLUSHED it now runs in the OR area.