[jlsporty]

I have a 95 YJ 4.0 5spd and on my way to work this morning I noticed my temp was bouncing between 190ish (normal operating temp) to 220-230. It would heat up then drop back down to the normal 190ish temp. I stopped and put about 1/3 of a gallon of anti freeze in the radiator thinking that maybe since the coolent was low that could be causing the problem. However after that the same thing continued to happen. It doesn't matter if I'm stopped at a light or cruizing at 65 on the highway the same behavior happens. Does anybody have any ideas? I'm doubtful it's a thermostat because it seems to be opening up when the temp gets hot.

Any thoughts/suggestions are greatly appreciated.

Jason

[70sElvis]

Could still be the thermostat. Maybe it is just sticking a little.

[YJGEEWA]

Fan clutch when it's warm at idle can you stop the fan with a piece of card board if so the fan clutch is bad? Water pump is it weeping little drips after you have let it sit for awhile? Or you could pressure test the system and see if you have a leak. Why did you have to add atifreeze?, that could be a good clue there.

[jlsporty]

YJGEEWA, I have noticed a few drips here and there coming from what I thought was my lower radiator hose (didn't inspect much because of the little amount of leakage). I haven't checked the levels for quite some time and I sometimes smell a little antifreeze in the garage from time to time but don't see anything on the floor so I figured the cap was leaking a little or something. I may just go with changing the water pump I was going to flush the system but wanted to wait until my leak was fixed. I haven't changed one in years and that was on a small block chevy. Is it pretty simple on the 4.0 liter? I haven't looked too closely... I'm sure I can do it as I just replaced the clutch 5-6 months ago but just want to know what I'm in for.

[YJGEEWA]

If you replaced the clutch I think the water pump should be sucker shot for ya. Just be careful when you buy it to match it up with the old one for ease of installation. Napa has reman # 58448, new # 42005, or 557136 they range from about $42. to $67. In my area.

[jlsporty]

I think I'll give it a try since it's leaking down there I figure I can't do anything but help the situation. Thanks for the advice guys...

[rustywrangler]

Tis your water pump. While you are in there, get a new thermostat anyway. Only an extra $6. Get a 195* therm and don't let anyone tell you otherwise. That is the stock therm.