Okay, here is my run down. Installed a new water pump, water pump inlet tube, thermostat, thermostat housing, and new clutch fan on Sat. Did all of this because I thought the dreaded bearing whine was the water pump, turns out it was the alternator. Will have to wait a week or maybe two before I can afford to replace the alternator out. Jeep has 162,000 miles and all of that was still original so I don't consider it a loss.

Upon initial restart it started with a very low idle speed, then came up to normal idle after a minute or so. Was idling fine until I put it in gear to move it into my normal parking place, then it started idling very rough and almost died. Acted kinda like the coolant was air locked at first, but I got burped and it appears to be cycling fine.

I've now driven it to work and home 2 days (15 miles one way) and back to work this morning. Adding coolant once during the time as I think there was still some air in the system. When I crank it in the morning it has a very slight rough idle, very close to normal. It drives fine and idles normal at red lights. Once I get either almost home/almost to work and have to stop at a light, it idles very rough and low. When stopping and putting it in park it idles really rough and low rpm (400-500 ish). I can rev it up to 1500 rpms or so and some times it will smooth back out.

It wasn't doing any of this before Saturday. I did remove the air filter and top half of the air filter box and hose to the throttle body to get to some stuff easier, but reinstalled everything just like it was before. Seems to be staying around 210 degrees after warming up and the temp gauge shows it cycling several times during the drive. Any ideas on what to check?

 

Check any rubber air lines you might have pulled off and see if they have cracks or leaks at all. Then recheck all wiring that was around where you were working for tightness.


By chance did you get water anywhere where it shouldn't have been?

 

Will do, did remove the hose from the CCV to the air cleaner box. Also wire from temp sensor and electric fan also.

All water was drained from the lower radiator hose at the water pump end. Spilled a small amount out of the radiator cap trying to burp it. Otherwise no on water.

 

I wonder about the temp sensor. The one in the thermostat housing. Not sure if this would apply to a newer XJ. This is with '96 XJ. Buddy had one. Ran like it needed a tuneup. Did a complete one including the fuel filter. Still ran like crap. Drove him nuts for awhile till he figured out it was the temp sensor. Maybe?

 

Took the IAC Valve apart and cleaned it over the weekend. All seems to be well again.