help on 91 temp.

[suthernoutlaw]

i have a 91 xj, with a 4.0, auto. i have a problem with my temp. its a engine out of a 97 with 26k miles. my temp runs right below the red on the guage. i have a new radiator, water pump, and i went from a 180 t-stat, to a 160. i recently put a new temp sensor in thinking it was faulty but still runs about 235. it runs perfect no problems, just temp goin up, and it doesnt do it the whole time im driving. just after a little while it comes up, in the evening its not tht bad...

 

[suthernoutlaw]

anybody?

 

[sidewys xj]

Gauge bad?

 

[bpatrick54]

I had a similar problem, it was caused by the electric fan not turning on. I rigged a switch inline on the electric fan and just turn it on manually. now my jeep stays just about the 180 -200 temp range even when parked.

 

[Thunder11265]

also check that the viscous fan clutch for the mechanical fan is working properly. the electric fan is only ment as a back-up if the mechanical fan cant pull enough air to cool, but it cant pull enough air to coll by it's self.

also when does it over heat, while idleing or while just driving down the road?

 

[firedog11ku]

I had a similar prob with mine. Neither fan was working properly, and the gauge was broke, it read about 180 when it was past boiling. That's how I came to have a 95 4.0 in mine. I fixed the fans and gauge, after the motor swap. Still was heating to about 220-230 range. I took the radiator to a local shop and had it boiled out the the fins straightened. seemed to take care of it. I hope this helps.


:looney:91 XJ laredo, bone stock for now.

 

[pauldo39]

You need to let us know when your jeep overheats. Does it overheat on the highway, in the city/idling, or both? Overheating on the highway is almost certainly a bad radiator, overheating in the city is lack of airflow i.e the fans aren't working, or the water pump is bad. Seeing how you said you replaced the water pump and radiator, those may not be the problem, but radiators can go bad very quickly especially if you got a cheap brand with plastic tanks, or the rest of the system was still dirty when you put the new rad in.

Putting in a lower temperature tstat will NEVER solve an overheating problem. The tstat simply opens earlier, making the jeep take longer to warm up to operating temp (leading to bad mileage, more emissions, and less power). Ask me how I know this. Put in a Mopar 195 w/ gasket, or any other HIGH QUALITY brand of 195. And remember that one overheat can completely ruin a good thermostat.

Hoses, serpentine belt, clogged heater core, pressure cap? Little things can make a huge difference

 

[92xjsp]

First off, I'd verify that guage reading - faulty temp gauges are not unknown. FInd somebody that has a temp probe (dealer, most shops, friend, etc) and warm up the engine to operating temp, then touch the probe to various parts on the engine block.