MustangGT,

I am experiencing the same problem that you describe in this thread (hope the link works - it was in Feb. 2005):

https://www.ford-trucks.com/forums/s...highlight=temp

Did you ever get this issue resolved?

I've got an 87 F150 w/300ci. This is my first winter with it and it's not a daily driver although I have driven it the past couple days. The heat is not that great and the temp gauge stays just left of the "N". I does seem to move just a little, but never gets to the "N". I don't think the gauge ever falls all the way to the left even when it is turned off.

Any ideas, anyone?

I did a search and read a bunch of threads, but never got what appeared to be a clear solution.

TIA

Chris

 

On a truck that old, I would flush the cooling system out with a flush kit from Autozone. Change the thermostat and refill it with the appropriate mixture - I use 75/25, but there are no extreme temps where I live.

It sounds to me like your thermostat is stuck open. The flush & fill is just because it probably hasn't been done in a long time.

 

Thanks Andy. I was thinking of doing that.

 

I did resolve my issue - it happened to be what I suspected.

The stock gauge is not very reactive to temperature changes in the coolant - it's slow to react. I had an autometer gauge on my other engine that was much more accurate.

It came down to air bubbles in the coolant system. My autometer gauge on my other truck (same problem) would flicker between 120-190 degrees when it was hot. I came to the conclusion that the air bubbles would make the gauge drop and when the water hit the sender again it would shoot back up.

I solved the problem by topping off the radiator and coolant oveflow - and sqeezing the upper radiator hose until I got the air bubbles out. It took a little playing with it to all the bubbles out. I also would drive it and top it off the next morning until it didn't need it. The gauge read normal after that.

I don't know if my heat improved - I doubt it - truck is junked now. Try what I did to see if you can get the gauge to read right. If you still can't, I'd wonder if my t-stat was sticking open. You can put a thermometer on it to see what temperature it's reading, if it's at 190-195 than you know it's not stuck open.

Flushing is never a bad idea...try the air bubble thing first...I'd get a motorcraft tstat as they're nice because they lock into the housing vs the generic one that you have to try and hold it centered when installing it. Makes it a lot easier to install. Be prepaired for tstat housing leaks - I had a very hard time getting mine sealed.

 

I was told by a mechanic friend that he thought that my 88 f250 302 was running hot. The guage was not showing hot and seemed a liitle low. The top radiator hose and the heater hoses feel extremly hot. The lower radiator hose almost feels cold. I changed out the t-stat (195*) thinking this was the issue but nothing changed. Any ideas or is this normal. Heater core has been relaced and heat works great.

 

If I'm not mistaken, the water flows from the top of the radiator to the bottom of the radiator - so the top hose would be hotter than the lower hose - you can also put a thermometer in the top of the radiator and read it's temp.