johns91xj

Hoping someone can help me so I stop throwing money at random parts to fix the issue. Recently bought a 96 xj with 100k on her. Very clean jeep. When you're driving on city roads it runs at the normal 210, when you stop on the city roads it heats up fast to around 225 right on sometimes right before the last white line on the gauge. When driving 70 on the highway the gauge reads around 225. As soon as you get off the highway and come to a stop it quickly heats up right before the red on the gauge. When you start driving again it goes back down to 210. I have replaced the thermostat with a 180 degrees thermostat, fan clutch, fan shroud, e fan is on a override switch which I keep switched on, and the fluid looks fresh. Took a IR temperature gauge to the thermostat housing and it reads 30-40 degrees less than what the gauge says. Pointed at the rear cylinder head temperature sensor and it reads 5-10 degrees less than what the gauge reads. Any ideas? I don't want to pop a head gasket. Thanks!

Martlor13

Clogged radiator or bad water pump it seems. Like there is not enough flow going on.

OldTires

I agree with Martlor. Flush the cooling system a few times (google it), and change water pump too. I would be tempted to get a new radiator too, but only after flushing the system - so the gunk doesn't get in the new radiator. A new radiator runs about $70. Coolant is dramatically cheaper if you buy it at Home Depot.

johns91xj

So should I try the water pump first then go from there?

BlueRidgeMark

Yeah, actually, I do have an idea. I got it from you.

Your gauge is off. Stop worrying about it.


Replace the sensor if it bothers you. If that doesn't fix it, replace the gauge.

Oh, and get that 180 T-stat out of there. It's made to run with a 195, and Mopar is the reliable one.


Get on with life.

johns91xj

5-10 from the rear sensor still means it's running hot. It's the second sensor I've installed.

johns91xj

All the gauges have been replaced.

johns91xj

I've had enough cherokees to worry about a head gasket popping. Hard to "get on with life" if I have to rebuild the top half of the motor. I'm going to try a water pump. Thanks.

johns91xj

Where is the best spot to point the IR gun on the motor?

tacklebox

Most say T-stat housing, however I've learned IR guns can be finicky, especially cheap ones and depending on your housing you could get an inaccurate reading from my experience. (my t-stat housing is clean and shiny) I seem to get the best readings on the head just barely off the t-stat housing.

1991cherokee

I would flush your cooling system thoroughly and replace Water pump, Radiator and install the 195 thermostat back in. A clean system and fresh parts should handle your temp issues. I have had similar issues and rarely does it not solve the problem.

johns91xj

Yea I'm getting two different readings at each sensor. So I'll try the front of the head. If it reads hot then I will try a water pump. The radiator and water pump look new but I'm not 100% sure because I didn't install them. Thanks!

Ben Reilly

I agree with the general consensus. I had a similar issue last summer. Go back to the factory thermostat. Replace your water pump and radiator. Wile your in there take the opportunity to back flush your heater core. That should do ya

Ben Reilly

And do hoses while you're at it

RickJames Bish

Recommendations on what water pump to get ?