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Won't warm up!!

8K views 8 replies 7 participants last post by  sbluke55 
#1 ·
The truck has always been slow to warm up and tonight it bugged me a bit. 2002 7.3, auto 2wd. Things I've done include blocking the radiator and installing the 205° thermostat. It's still never hit 195, even in the summer... tonight it was 40° when I left work, cranked it up and put it on my 1100 rpm idle tune for 5 minutes and hit the road. Truck ran for 25 minutes and made it up to 147 on my scan gauge. Last year, I don't think I saw 180 all winter, and that includes long trips. What in the world can be done to help thing warm up??? It runs like crap all winter and I waste so much fuel letting it idle.
 
#2 ·
Fwiw I let mine idle for 20 minutes to warm up, drove a solid 25 minutes and still never got to 160 on either my iss pro gauge or cts. It was low 40's and I also have the 205 thermo. Pretty sure the ebp helps with this but I wouldn't know cause I don't have one.

I think most 7.3's just hate the cold weather. My buddies 6.0 warms up much much faster and once driving hits operating temps in about 10 minutes.
 
#3 ·
Actually there is no coolant temp going to the PCM at all.
What you are reading on your scan gauge from the OBDII plug is bogus.
 
#8 · (Edited)
This is what All Data says

The Engine Coolant Temperature (ECT) sensor is a thermistor device in which resistance changes with temperature. The electrical resistance of a thermistor decreases as the temperature increases, and increases as the temperature decreases. The varying resistance affects the voltage drop across the sensor terminals and provides electrical signals to the PCM corresponding to temperature.

I don't see a plug on the PCM for ECT though so does the engine temp gauge get the reading form the oil temp sensor to determine engine temp?
 
#5 ·
Nobody knows why.
Google ford 7.3 ect or coolant temp PCM .
 
#6 ·
I'm not going to get in the middle of the 7.3-OBD debate, but have you ever verified or swapped your coolant temp sensor?

It seems like you've had a bunch of system changes with no real change in measured temp. Maybe the temp sensor is NFG.
 
#9 ·
Yep. The oil temp is read by the pcm. That's what you have to watch. The oil cooler is very good and the temps between the oil and coolant army too far off.
 
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