Temp gauge going full hot then normal.

[jetjock15]

Guys, please help, always appreciate all advice. My 2003 4.0 explorer has been acting weird. Once in awhile it goes from normal to full hot fairly quick, the "check gauge " light will flash, then it drops down to normal. Usually only does on initial warmup. I figure the thermostat is getting stuck and figure I'll try to replace. Always like to post on here first to see if others have had similiar issue? I just had radiator replaced 2 months ago because original started leaking at seams. Don't know if two issues are related but it didn't heat up prior to radiator replace.

Thanks

 

[corkey]

sounds like air in the system,, check the rad , see if it's full

if not fill it up, and let it run with the cap loose to burp the air out,,, than fill er up,,


if it is full , you may be right,, thermostat change time,,,

 

[JoshMcMadMac]

Unfortunately the temperature gauge is electronic and does not show a good representation of the actual coolant temperature. It will rise to the middle of the gauge and stay there for the entire "normal operating temperature" range. It could be 190ºF or 220ºF and the gauge would remain in the exact same position. Only once it crosses a set temperature threshold will it rise, and then exhibit what you have seen...topping out. So, you might be running hot most of the time and just barely pushing over the limit on occasion. It would be helpful to use an OBD-II reader to get an idea of what temperature you are actually running at.

 

[jetjock15]

Ok thanks guys, the air is system could be feasible since I just had radiator installed and problem started. I don't think the radiator has a cap, just the overflow bottle, maybe I'm wrong, will check out this weekend. If it's just the overflow bottle, do I just leave cap off that to bleed air out? Don't recal that cap being a pressure/sealed type of cap. Wife has car into evenings, only reason I can't just go look till weekend.

 

[BrooklynBay]

Check the temperature with a thermometer or a digital meter with a temperature probe. An IR gun might work too. If you see that the temperature is correct, then it might have a bad thermostat or the temperature sending unit for the gauge might be bad.

 

[silverfox103]

I had the exact same problem with my newly purchased 2003 Lincoln Aviator. The mechanic replaced the waterpump, thermostat and bled the system........problem cured. I was not at home so I didn't have any tools. If I were to guess it probably was the thermostat, but it's fixed and I'm happy and relieved as I was 1500 miles from home.

Tom C.

 

[jetjock15]

Replaced Thermostat and hadn't occurred since.