Originally Posted by salad

I'll only reply to what I know lol

2. XJs have to be ridiculously tight, the best belt is Goodyear Gatorback. NAPA doesn't carry these but a number of other places do, including rockauto.com. For a 2000 the model is GTR-4060950

3. Absolutely a bad U-joint can cause this, as well as a dry slip yoke (on rear of tcase under rubber boot, take it apart and jam with grease) and of course wheel balance.

4. What temp tstat did you install, and did you replace the temp sensor at the same time? How do you know that this is actually happening? Stock setup is 195 degree tstat and the electric fan should come on at around 215.

5. Bad switch or a short. Around the tcase its possible for wiring to get chewed up by the driveshafts or little furry monsters. Most switches fail in an open style (never come on at all) so I'd look at the wires first.

Cheers

Originally Posted by black2000xj

1.water pump is leaking on my jeep ,anything i should know? do cherokee's like certian water pumps? I get all my parts from napa
----->How bad was it leaking? Sometimes I have a seepage issue with my thermostat after a longer drive, other times it's fine. Could be gasket or cracked lines.
2. replacing the belt while im at it, again any issues? cherokee's like certian belts or not?
-----> good advice given already, it sounds like!
3. Third issue is some vibrations accelerating and decelerating.
feel is when i hit 30 mph, its gone by 40 mph....then i feel it when i let off the gas and coast till about 30 mph /....could it be a u joint?
-----> a good way to test ujoints: on level ground chock a wheel, put jeep in N, with the parking break on and crawl under and try to twist the driveshafts. If there is any play, then that can/will contribute to vib's. There are, as mentioned, other contributing factors like bushings, TRE's, wheel joints/bearings, wheel balance..
4. My jeeps thermostat...its brand new, but when it opens the electric fan kicks on for some reason. Then when the stat clicks off...so does the electric fan
----->There aren't any bypass's installed right? I'm not familiar with e fan's.. A guess might be its supposed to?? Idk..
5. any my part time 4wd light is on, when my jeep is in 2wd....im assuming the switch is bad in the t-case?
----->Maybe a shorted wire or, more likely is yes, the TC switch is bad. OR! (depending on year) it could be a vacuum issue..
Any help with any of these issues would be great...just list what issues your commenting on

Thanks
Scott

Originally Posted by VTJeep

hope some of it helps!

Edit- cool you got fan worked out. What was the prob/fix?!

Originally Posted by cruiser54

New water pump. Do the belt at the same time. I only use the factory stat any more. 83501426.

Originally Posted by black2000xj

well i think i have it fixed....

turned out the electric fan would turn on when i had the defrost on

non of my other jeeps did this...but i looked it up and its normal to have the electric fan come on with defrost

now my clutch fan seems to make a little more noise than normal...but after driving a car for a year...gotta remember those normal "jeep noises"

Originally Posted by salad

Ah... I was on my phone at the time and I thought you had a 2000 XJ. Didn't see the 1999 set in your profile and you didn't post it. They changed the behavior of the electric fan between 1999 and 2000 model years. The actual change is on older XJs the electric fan turns on as soon as the AC compressor is engaged. On all models the AC comes on with defrost if it's above 1 degree celcius. Of course since your AC is on there's more heat pumping out, which means the clutch fan pulls more air, making more noise

Cheers