Ford Explorer Sport 2001 - Issue with temperature gauge

[zbizzy]

I have a 2001 explorer sport with 160K miles on it. In the past couple days or so, when I run my explorer for the first time for the day, the temperature gauge will rise all the way to the hottest, and the check gauge light comes on - meanwhile only cold air comes out of the vents.

Then, after about 5-10 minutes it drops down to a normal temp (halfway between L and H) and when it does, the heat kicks in., and then it stays at the normal temperature range for the duration of my driving, with no real fluctuations.

The radiator fluid is at the right levels, so that doesnt seem to be the issue.

The strange thing is, it only happens from a cold start in the first part of the day - doesnt happen after work, or any other time of the day after it has been running.


any ideas what it could be?

i might note, when i checked the fluid this morning, it did have sort of a funky foam on it, which i gather means it needs a flush of the system and new fluid....

 

[law2220]

Hello, I attend college for high performance automotive and have 4 classic fords and a 1994 explorer, you problem sounds like your thermostat is sticking, what happens is thermostats are opened as the fluid heats up and the metal spring in the fluid contracts due to the heat now sometimes due to gunk and other issues they stick. So what is probably happening is its not opening at the right temperature and after it over heats the spring contracts enough to break the valve open and then it works fine, overnight/long periods I'm guessing the thermostat resticks and then does it again, I would suggest changing the thermostat and flushing your system.