Another day, another issue with my poor XJ.

90 XJ, 4.0, Auto, 103,000 mi

Put in a new rad. While bleeding the system, temp got pretty high but as I bled the coolant, it went to normal temp. I let it sit for a few minutes then went to start it agan and it wouldn't even get to WOT and wouldn't get warm enough for the elec fan to kick in.

I've been driving it to work (a couple miles) for the past few days and the temp stays low. I let the XJ run ten minutes before I even drive it because the weather here has been around -10*C to -15*C (5 - 15 *F). Once I start it, let it sit and drive for 5-10 minutes, there is some heat coming out of my defrost but not enough to throw alot of heat.

My temp gauge reads 55*C (around 130*F) after running for a while. Thats about as warm as it will get.



Is this a thermostat issue?

After I swapped rads and bled the system, the temp did get to about 115*C/240*F but I shut it down and released the trapped air. For a few days after this happened when I would shut the jeep down, I could hear ticking from the front of the engine. started real fast, then gradually slower then stop. It runs great though. No fluids leaking, no knocking, no ticking when driving (that I can hear) steady RPM.

Any ideas?

Thanks!

 

It might be an thermostat issue. If you can get an orginal Jeep ( Mopar ) thermostat it would be the best, others makes have been hit and miss.
I put in new Stant thermostats that did not work properly ( they tends to open to early so newer get any heat and that is not fun in wintertime).

 

First thing you should do is verify your temp with a IR thermometer aimed at the t-stat housing.

 

Your thermostat went into fail-safe mode when you overheated the engine.

It is now locked open--by design.

Replace your thermostat, preferably with a Mopar one. Probably need to change your oil and filter, too, due to you cooking the engine.

Good day.

 

Roger that on the MOPAR. 185? or 190?

Is this an expensive purchase? Or do I have to go to a shop and ask them to take a reading for me?

Do you mean cooking by letting it overheat that one time?

 

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The recommended temp is 195

I just found one at Harbor Freight for a real good price. I tried to post a pic of it but for some reason it wont let me. Anyways, Harbor Freight has one on sale for $19.83



I'm sure he does. You did get it pretty hot and you are better off changing them out.