Vehicle will not reach its temperature of 195

TEXCHANDON

MEMBER
1999 DODGE DURANGO
5.9L
V8
4WD
AUTOMATIC
100,000 MILES

My vehicle will not reach its temperature of 195. It has a clutch fan that runs none stop while engine is running. Temperature reads at 130 to 150 while driving. It is winter and I am not getting any heat. But I do know the thermostat opens at 195. With that fan running I get no heat. Can anyone tell me what is happening with my SUV please? It is cold as heck out I need heat.

Friday, November 30th, 2018 AT 5:12 PM

3 Replies

CJ MEDEVAC

MECHANIC
11,004 POSTS

How do you know the thermostat opens at 195 degrees?

Just because that it is stamped 195?

Thermostats can go bad a stay open, some brands will even "default" to the open position if they fail to prevent an overheat situation.

Back to the fan clutch possibility, see my picture below.

Your turn,

The Medic

Image (Click to make bigger)

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Friday, November 30th, 2018 AT 6:12 PM

TEXCHANDON

MEMBER
2 POSTS

Yes, I can hear and feel the thermostat opening. But with the fan is it suppose to kick on when the coolant reaches a certain temperature? And in that picture you sent if that tab is broke off. Does it mean the clutch fan is stuck locked in? Or what does it mean? On my truck it stays running from the time you start it stop once you shut off the engine.

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Wednesday, December 12th, 2018 AT 12:49 AM

CJ MEDEVAC

MECHANIC
11,004 POSTS

That's a bi-metal spring. As it heats or cools it "twists" the center dealee.

The "center dealee" is what locks fan on the shaft (when the radiator is hot the spring twists)

As it cools down, the center dealee twists the other direction and allows the fan to freewheel on the shaft.

The quick rule of thumb for checking to see if the clutch is doing right is to get the vehicle to operating temperature then stand near the fan.

After a bit you will hear the fan roar loudly (locked onto the shaft) than after a minute or so the roar will go away (now it's freewheeling) It will do this over and over as the radiator requires more airflow to cool it.

The Medic

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Thursday, December 13th, 2018 AT 7:54 PM