Hi All,
I have a 4.7 flex in an 07, and i've got a bit of a funny one with the coolant temperature. It may well just be the thermostat, but i wanted a second opinion before i start wrenching in a Canadian winter (note it was the same in fall when it was normal temp outside).

Basically the max the temp gauge ever shows is a touch above 3/8's of the way up, which on every other vehicle ive owned seems a little low. I checked the coolant temp via the obd2 port and its a steady 95c (195f) at its max.

My question is basically, is do i have a problem, if so will changing the stat fix it?

my main reasoning for this it that the most ive got from a tank is 400km (250m) of which 75% was highway driving, which even for a truck seems a bit low, and my thinking is if the engines running cool, then it will be fuelling rich.

Can anyone offer any insight? am i just worrying over nothing? Many Thanks

 

The obd reads correct temp, but gauge shows low. Think i'd take a manual reading with a temp gun. It's possible your gauge is incorrect.

 

Your temps read by the PCM are correct. I ran into the same problem with my 98 Ram. The gauge didn't go up to where I thought it should, so, changed the stat, WITHOUT checking things first..... Imagine my surprise when even with the new stat, the temp gauge was in the same spot.... Checked with a scanner, yep 195*..... I didn't need to change the stat after all. Trust what the PCM tells you. Note where the gauge reads, and use that as 'the right spot', if it starts running much above/below that, then you need to worry.

 

Thanks guys, sounds like I don't need to do anything then!

does 250 miles to a tank sound unreasonably low to you? Or should I quit chasing imaginary problems?!

 

If you really want to wrench in the Canadian Winter, you can come to Ottawa and help me change either: rear brake cylinder, front brake caliper or brake master cylinder. Haven't found what is leaking yet.

Temp gauge is normal for these trucks.

You have a Chrysler V8, Mileage sucks. Sucks on the V6 too. You can pull just about anything and pass most things but a gas station. Keep it tuned up, and don't go chasing miracles . . . .

 

My Father always said, "Don't fix something, that's not broke!"

 

"Nothing's so good that I can't break it by trying to improve it!"

 

Hard no... I'm in BC... It's only -15 here... None of your -30 Malarkey! Ha ha

 

Pretty normal. Mine might go halfway when towing in the summer but the rest if the time is about where you describe.

 

If it has a 180° thermostat in it thats as high as it will get. Pretty common mod in southern states. If its done it the entire time youve owned it that could be why. Otherwise a needles width below half is the normal spot.