Overheating ??? Or Computer Glitch ??

[Fordman]

Hi guy's, It's been a while. I have been really out of the loop for a while. I had a good one last night. On the way home from work, my temperature gauge pegged all the way on HOT !! Beeps and lights were all on. I thought the engine was going to blow. As I started going up the road with no place to pull over, all of a sudden the gauge started to come back down. I finished driving home and it seemed okay. Got home, shut off the car then re-started it a couple of minutes later. Now the gauge was as it always is 1/2 way. Weird, huh? I opened the hood the engine didn't seem any hotter than normal, the fan was turning fine. I let the car run again in the driveway for about 15 minutes, the gauge never moved. I personally think I either have a sensor going bad or a glitch in the computer. I really don't think the car overheated at all. Anyone ever have this happen??

 

[JoeyLincolnMK8]

i have had this happen to my mark, it would spike all the way. i have changed out my t-stat to a cooler one. it worked, to a certian point. it would still spike but not all the way to HOT. my next thing is to get a new radiator. but i would look to see if your AUX fan is kicking in when it suppose to, and make sure you do not have a leak in your radiator, i doubt that it could be your water pump since it is only 4 years old. but i would test it just to make sure. did you check your coolant to see if you are not running low? i am pretty sure it might be just something stupid!

 

[Fordman]

I should have mentioned that. All my coolant levels were fine. And if the thermotat would have stuck, water would have to go somewhere. I would have seen it. It was all bone dry. A friend of mine who owns a couple of Mark VII's told me that he has had a problem with them getting air in the system. But my system has been closed and never opened.

 

[Calabrio]

I'm fighting temperature gremlins too.

The engine doesn't overheat, but it climbs up to the "R" a little too often.

I've replaced the radiator.
The hoses
The thermostat
The water pump
The belt
the fan motor

Fortunately, I wasn't just buying parts for fun. The motor did die. The radiator was leaking. The hoses had at least 100k on them. The thermostat did stick closed once.

And I'm stumped. I ran up the highway for a half hour with the cruise on at 70mph and the needle never passed the "A", but once I pulled off the highway and started driving again, it immediately crept back up.

Running out of things to replaced, I'm left wondering what the problem is. Could it be the radiator cap? Is it my gauge or the temp sending unit?

As mentioned, it doesn't overheat, but it runs warmer than I'd like. I'd like this car to hold around the "A", or at least only fluctuate a little bit.

 

[Fordman]

I ran into that a few years back. I had an overheating problem and all it was, was a bad radiator cap. But I was able to have one the techs in my shop test it. It was releasing at 2 lbs. So it wouldn't hold pressure. Unfortunatly these caps can't be tested. I guess just try and replace. 100k it's probably bad. My car only has 48k. Today it ran perfectly fine. It will be hotter out when I leave work, so I'll find out more at 4:00 P.M.

 

[Calabrio]

The coolant cap isn't particularly expensive- I might as well just replace that anyway. The car has 185k on it.

 

[Soulworkout]

LS Temp

I had this some problem. It’s a temp sensor malfunction. The LS as no mend range temp reading. The car will either register normal or hot. When the temp sensor fails it tells the cars computer that the motor is running hot which drives the temp way up and will sometimes stall the car. This is a failsafe so you want blow the motor. This will also happen sometimes if you incorrectly mix the coolant. The LS cooling system is really sensitive. It is important that you follow the manual very carefully when caring for the cooling system. Also, unwanted air in the cooling system can also cause this problem.

 

[Fordman]

I had this some problem. It’s a temp sensor malfunction. The LS as no mend range temp reading. The car will either register normal or hot. When the temp sensor fails it tells the cars computer that the motor is running hot which drives the temp way up and will sometimes stall the car. This is a failsafe so you want blow the motor. This will also happen sometimes if you incorrectly mix the coolant. The LS cooling system is really sensitive. It is important that you follow the manual very carefully when caring for the cooling system. Also, unwanted air in the cooling system can also cause this problem.

Thank's, thats help to know. I went out lunch time and got the car to operating tempture, then got an LED gun from one of our tech's. It was running about 181 degrees.