I too have been plagued with the lower coolant temps so far this winter. Truck has had a hard time getting over around low 180s when temps are south of 50 degrees outside. In the summer I run hotter than most, usually 198-203. Now for the wierd part, we have had mid teen mornings the last 2 days here in East Texas and yesterday my batteries completely gave up the ghost. I put new batts on and for the first time plugged in a block heater last night. Ok by the time I start driving for work today the outside temp is 37 degrees outside (noonish). My coolant temps which have had a hard time passing 180 hovered for my 30 minute commute at 189-192 CONSISTANTLY. Fast forward to my commute home a few minutes ago again with temps in the low 30's, CONSISTANT 189-192. Now the only thing done to my truck recently is my ficm repaired with the atlas 40 right after christmas but my temps didnt change. Now since my batts and first time use of my block heater Im running normal temps. Any thoughts or explanations?

 

I'm watching this one

 

Where's Mulder and Scully?

Josh

 

When was the last time you replaced the thermostat?

 

Mine is down to 184 now with 45* ambient temps and it's not 6 months old yet. It MIGHT get to 188 if I push it hard but won't maintain temp. I think I'll hit the parts store for a warranty replacement since it should be 12 months.

 

Sounds like thermostat. We have been having -10 to -15 degree air temps here the past few days. I have a cold weather cover on the front as well but I still get 188 degrees without a problem.

 

Mine will drop to 187-189 with below zero temps sitting at a long stoplight, freight train etc. but is back to 190-192 once the speeds are over 40.

 

My truck has been sitting for a week now. Drove it to work this morning 16*f ambient temp. 181* ECT. Thermostat is just a few weeks old.

 

I can watch mine open at 190. After that it's 182-184 at highway speeds. I need a thermostat for my oil cooler (BPD) too. I wonder how much that's affecting my ECT since EOT only holds 164.

 

My thermostat is about a year but I put it in just to do. It read the same as the old one. I just swapped back to the old one a couple months back to see if new one was going out because of the higher temps. No change.

 

What about today temps of fWT and EOT, is it the same as yesterday?

Mine is about 182* to 186* fWT and 190* to 192* on relatively flat 65 to 72 mph. When it has to work up an incline, the temp went to 190 for fWT but drop down right away...

Summer time always about 190* or more, but the temp difference was never above 10* at 65 to 85 mph.

 

46* outside, 70-75 mph, 188-193 ect/195-198 ect...something else, my truck was completely unhooked from batteries for about 4-5 hours, complete reset maybe???

 

I asked for, and received, a Cabela's winterfront for Christmas.

It made a HUGE difference - cut morning warmup time in half and I now see 192+ ECT where before it was 175-185 at best.

Well worth the cost....

You may not actually have a thermostat problem.

 

I agree with these covers; The fia snap on blankey comes with a summer bug screen for about 50 bucks!

 

I got the same one ...works good!