Cool engine temp

I know i we have been through this before but im going to throw it out there again at the risk of being shot at

My engine only runs … im guessing 160-170 occasionally gets up 190 range where it is supposed to be.
I have new stat and have read in here water may be by-passing the stat. How could that be?
I called Napa this morn and the guy told me its not even possible

Im in northern alaska and dont have a garage to tinker in
I do have a garage i can use but i need to know what to do when i get there as i cant leave it and only have about 2hrs at a time to work on this never ending heating issue that causes or is at least a contributor to poor cabin heat.

95 jeep 4.0 Manual 150000 miles

There are two radiator fans in your vehicle. One is belt driven with a fan clutch, the other is the secondary electrical fan that operates when the AC is used. Make sure that the electrical fan doesn’t run unless the AC is on. If that fan isn’t operating, check for a faulty fan clutch for the belt driven fan. To do this, with the engine cold, spin the belt driven fan by hand. If the fan clutch is good the fan should spin at least one revolution. If the fan doesn’t spin but stops immediately, the fan clutch is defective and is pulling air thru the radiator when it shouldn’t causing the overcooling.


Clutch fan spins but i didnt check for a full rotation
Electric fan also comes on when engine get hot and did come on last winter but i havent heard it this winter.
Does heater on defrost qualify as “using the AC”?

How common is a faulty thermostat…as in opening at the wrong temp?

If the thermostat has room to rattle in its well enough coolant can bypass it to keep the engine cool in frigid temperatures. Also, some Jeeps used a reservoir that connected to the heater return hose and the radiator and if the heater return hose is kinked coolant will bypass the thermostat to the radiator. Just look around and feel hoses. If the temperature is 170 but hot coolant is reaching the radiator feel around and see how it gets there.

I dont belive there is a reservoir of that nature but i will check.

Lets say the stat is lose in the housing…any tricks to making it seal or just find the proper stat?


The thermostat should match the recessed area in either the cylinder head or water outlet. Always check the temperature rating stamped on the replacement thermostat, discount auto parts stores always try to sell me a 160 or 180 degree thermostat. Yours should be marked 195 F.

When you start your engine cold and drive for about 3 miles the engine temp should reach 120 to 150 F, stop the vehicle and feel the upper radiator hose, it should be cold, no coolant should get passed the thermostat.

Will do. Thanks

Um…you’re in Northern Alaska and the car is housed outside?
When I lived in North Dakota we couldn’t get our engines to operating temperature without block some or all of the radiator. And on really cold days it would still take forever to get the engine to warm up.

I think I know what’s causing yours to run cool. Northern Alaska.

Agree; you need a block heater and also cover the radiator with cardboard. Also use 0W30 oil in the crankcase.

I’ve worked on the Beaufort Sea and had -50C weather. We even had sythetic oil in the transmissions and an additional magnetic stick-on oil pan heater and an in-car heater to take the chill out.

I have block heater and oil pan heater and snap on grill guard

The 06 toyota will run you right out of the truck without any grill guard

I grew up in Wisconsin and over 4yrs here in northern ak. The toyotas ive owned never had any heating issues even at -45 or -50 One other jeep i had did have the same heater problem.

I should probably go to synthetic but 0W30?

In your other thread it was suggested that your heater core was plugged up. Have you done anything about that?

Im looking into that this weekend. Its not plugged but im thinking restricted because it does put out some heat.

The posters here are assuming the engine does not get warm enough. On the other hand, if the heater core is plugged or the coolant valve (if it has one) is defective, you won’t get any heat no matter how warm the engine gets.

The 0W30 or 0W20 synthetic is great oil for easy starting in cold weather. You won’t always be able to plug in. Toyota recommends it in the latest vehicles for winter use. I have used 0W30 semi-synthetic as early as the late 70s in my small block Chevy V8 and 350 V8 Oldsmaobile, when Shell introduced it as Shell Synarctic. You will have to check the oil more often if you have an older car. This oil is very slippery and will find any leaks. But don’t worry about the film strength of synthetics.

There are a lot of 0W… oils on the shelf, especially in Alaska. Mobil 1 may even have a 0W40, which I don’t recommend for where you are.

The “pour point” of these 0W oils is about -45/-50F, so it will be easy on your starter as well.

Mucho Buena

Im back…dont shoot!

I just got back from town(30 mi. round trip) I popped the hood to check the temperature of hoses ect.
When i squeezed the top radiator hose i could hear the radiator cap “clink clink” it appears its … open?
Is the cap junk?

Was it something i said???

or was it something i didnt say