temperature

[chicofuentes0224]

Well since the mj never warmed up now that weather has cooled down I figured the thermostat must be stuck open. Went to change it with a 190 dgree thermostat and found out ther was no thermostat in the truck. Guess the PO took it out to resolve the overheating issues. Now my truck idles at 215 to 220 and gets hotter as I drive down the road even though it's 30 degrees outside. I just flushed the system added the thermostat and replaced the plastic tank and lid by the firewall due to a crack. I even bled the coolant through the temp sensor in the back of the head and the truck will get really hot unless I kick the heat on full blast which isn't a problem now but will be in the summer. To top it all off I can't get the electric fan to work. I checked the motor by hooking it up to the battery, it worked, changed the sensor switch on the radiator and changed the relay on the driver's side fender and still no go. The radiator is not the original and looks to be in good condition from the outside. Anybody got a clue on what to do next?

[Pete M]

I gave up trying to get my E-fan to come on automatically and wired it up (through a new relay) to a switch in the cab.

[carnuck]

I hooked my fan up by unplugging the AC compressor for the winter. When I put it to AC, the fan comes on.

[JeepcoMJ]

I hooked my fan up by unplugging the AC compressor for the winter. When I put it to AC, the fan comes on.

 

 

...uh...what does that accomplish???? you don't need the fan in the winter, same as you don't need the a/c. it's cold. now you have to drive with A/C on so you can cool your engine (more than it should need to be)...I don't get it lol :nuts:

[chicofuentes0224]

OK so guess what, by gauge reads high by like 40 or 50 degrees. Guess I have no problem.

[mjeff87]

I hooked my fan up by unplugging the AC compressor for the winter. When I put it to AC, the fan comes on.

 

 

...uh...what does that accomplish???? you don't need the fan in the winter, same as you don't need the a/c. it's cold. now you have to drive with A/C on so you can cool your engine (more than it should need to be)...I don't get it lol :nuts:

 

Because when the AC compressor engages, the fan comes on to regulate head pressure in the condensor in front of the radiator. Disco the compressor, it doesn't engage, but the fan does.

 

Jeff

[FxRacing282]

Well since the mj never warmed up now that weather has cooled down I figured the thermostat must be stuck open. Went to change it with a 190 dgree thermostat and found out ther was no thermostat in the truck. Guess the PO took it out to resolve the overheating issues. Now my truck idles at 215 to 220 and gets hotter as I drive down the road even though it's 30 degrees outside. I just flushed the system added the thermostat and replaced the plastic tank and lid by the firewall due to a crack. I even bled the coolant through the temp sensor in the back of the head and the truck will get really hot unless I kick the heat on full blast which isn't a problem now but will be in the summer. To top it all off I can't get the electric fan to work. I checked the motor by hooking it up to the battery, it worked, changed the sensor switch on the radiator and changed the relay on the driver's side fender and still no go. The radiator is not the original and looks to be in good condition from the outside. Anybody got a clue on what to do next?

 

how hot are you running?

[chicofuentes0224]

By putting a thermometer in the reservoir tank i'm between 180 and 210, just perfect I guess.

[Oizarod115]

By putting a thermometer in the reservoir tank i'm between 180 and 210, just perfect I guess.

 

i would still see if you can't get a laser thermometer or something of the sort just to be sure, then replace the sender!

 

250-260 shouldn't hurt a 4.0 much, i passed emissions at 250* :oops: OOPS guess the gauge wasn't faulty after-all (i had thought/been told the gauge was bad when i bought the truck)

 

but i drove it like that for a long time she still purrs today, (only now at 190ish) :brows:

[Pete M]

Inrared thermometers are awesome. :D I just picked up a craftsman one.

[mjeff87]

I just "borrow" the one from work..... ;)

 

but they aren't as expensive as they used to be. Good diagnostic tool to have in the shed, when ya need it.

 

Jeff

[chicofuentes0224]

We checked it with a laser thermometer on the block and the hoses. Every thing looks good between 180 and 210. Bt do you think I need a new gauge or sender. The sender is 2 months old.

[FxRacing282]

yeah id say so, new sensor. i was spinning I'm nud with my friends and suddenly the guage went from 180ish to bouncing off the little stopper and then i hopped in the passenger street (town road no license at the time) and the rad blew right there. you wouldnt want that to happen to you.