1996 ford explorer running hot even after thermostate replaced twice

[stafphoto1]

Ok so heres the deal I have a 1996 ford explorer 4x4 with the 4.0 v6 engine in it. About a week and a half ago I was comming home and eneded up having the idler pully bearings freeze up which causing the pully to come off and the belt to be thrown. The truck got hot enough to loose some coolant do to the heat of the eninge. I replaced the pully and also had to replace the thermostate because I was using a fail safe one which locked open do to the engine heat. I have since replaced the thermostate twice and burped the system and the engine temp is still getting warmer then it should be. Its not trying to overheat but the temp guage is climbing higher then it should be. The engine seems to be running fine and the oil looks ok so does anybody have some ideas on what it could be? Id like to get this fixed.

 

[koda2000]

where on your temp gauge does the needle sit when fully warm? it should be about in the middle of the gauge. overheating the 4.0L OHV engine can result in a blow head gasket or cracked head. is there any sign of white smoke, out of the exhaust, when you start it cold? is the coolant level in the expansion tank (and in the radiator) staying constant?

 

[stafphoto1]

Not noticing any white smoke comming from the exhuast. The oil is staying clean with no funny color to it. And the coolant level is staying constant. The temp guage is running higher then in the middle sometimes to within maybe an 1/8 of an inch to the top white line at times. And sometimes it's not that close to it. Some of it depends on if I'm actually driving or just sitting there as well.

 

[stafphoto1]

anyone have any ideas?

 

[Turdle]

Try a new radiator cap. Loss of pressure may cause this. They are very inexpensive.

 

[koda2000]

Try a new radiator cap. Loss of pressure may cause this. They are very inexpensive.

the rad cap does not effect water temp. just boiling point. something like 3 degrees for each rated pound of the cap. 16lb cap should increase the boiling point of the coolant by 48 degrees. has no effect on coolant temp.

i'm thinking clogged radiator. you can try taking it to a radiator shop to have it boiled and tested for flow, but i'd just replace it (they can be had for around $130-$150 on-line). while your at it flush the cooling system to get any crap out of the engine block and heater core. one other thought is a bad water pump due to impeller issues.

have you actually checked the coolant temp? you can do this with a meat thermometer in the rad cap hole (won't boil over unless the coolant is exceeding the boiling point, 212 at sea level) or you can use one of those infrared temp checking tools. as long as the coolant temp is below 200 you're good to go. screw the gauge.

 

[stafphoto1]

The radiator is actually new, well about two months old anyways the old one was leaking so it was replaced. But then I had the stupid pully break and thats when this issue started. Ill try the meat thermometer this weekend. I was also thinking about the waterpump myself.

 

[BubbaFL]

The radiator is actually new, well about two months old anyways the old one was leaking so it was replaced. But then I had the stupid pully break and thats when this issue started. Ill try the meat thermometer this weekend. I was also thinking about the waterpump myself.

Could be the water pump, or the fan clutch.

 

[stafphoto1]

Thanks Ill give that stuff a try.

 

[Dean1947]

I had a similar problem with my 95 Explorer. Discovered that the gauge in the dash was the malfunction. Engine wasn't getting hot at all. Your mechanic may have a laser thermometer that he can use to measure the operating temperature. Added an aftermarket temp gauge and had no problems since.