Hey all,

My truck will only warm up to 170ish even after hours of highway or city driving. I've also dropped about 2 or 3 MPG's (winter blend of fuel already taken into consideration). Could the engine be running open-loop at this temp causing poor mileage?

I've replaced the thermostat (both were 195), coolant temp sensor, and burped the system completely. From what I can tell, the fan clutch is working correctly - free wheels with some resistance when the truck is off and spun by hand, and will spin for a couple seconds after the truck is turned off. Everything is operating correctly, no other problems except for mileage and a cool motor.

Don't think it matters, but I did bypass the A/C compressor with a shorter belt. Can't put the original back on yet because the A/C pulley is seized, but could that really cause the issue?

Computer was scanned and it's clean - no codes, no other problems. I'm stumped. If anyone has any ideas or has gone through the same issue, your help is appreciated!

Thanks,
-Dan

 

did u install the thermostat correctly. the metal bars face out and the opening faces u and toward the motor the metal bars go left and right. (----) and the openings are toward u and the windshield.

 

How is your front 02 sensor?

 

unless its -50 or some other north pole type weather, it sounds like either your t-stat or temp sensor is bad, or its not seated correctly, or you're drilling too big of a hole in it (if you're drilling a burp hole).

did the original temp sensor and t-stat act this exact same way?

 

Yup, t stat is in correctly and the previous sensor and stat acted the same way. Temps have ranged from 40s to 0s ouyside, my truck acts the same way. Both O2 sensors were replaced less than 1 year ago, but would that affect my operating temp?

Thanks all,
-Dan

 

Plug a scanner into it, and see what temp the PCM thinks the engine is at. Not like the dash gauge is amazingly accurate....

 

Is that scanner something I can obtain at advance auto or the like? All I've got is my superchips to check codes.

 

Give 'em a call, and see if the can read data as well. Some can, some can't.....

 

Sounds normal to me. My old gunked up motor and old radiator had no problem getting to temp. Now that everything is new and clean with a 195 degree t-stat my truck will not get to operating temp at 30 or below. I have over 1/2 the radiator blocked off with cardboard and it still wont get to temp when its in the teens or lower. This is all on the highway though around town I can get the temp up.

 

This just happened out of the blue for me though. The new thermo was only to six the cooling issue. I can't get the trick to heat up highway or city either. I'm gonna buy a infrared temp gun to eliminate the possibility of a faulty gauge. Will update

-Dan