Every time I turn off my jeep, a clicking noise starts for a few seconds and then it stops. It sounds like it is coming from the valve cover, but not sure of what it is. Also when I use my 4wd the temperature goes up but not up to the red line. Even when I am using it in the city the temperature starts raising and when I shift to neutral the rpm goes up to about 1500-2000rpms.....,

Any suggestions or guidance as to what could be the problem.


1999 jeep XJ sport i6 4 0 4x4

 

Ticking sound is normal. That's the sound of the rockers moving as the lifters let out the oil.

As for the temp issue you need to inspect your cooling system.

High idle no idea.

 

It's gonna blow!

I wouldn't worry about it. Things are cooling off and draining. No big deal.

When was your last cooling system overhaul? It's probably time. You will want to flush and flush again, replace the radiator, hoses, thermostat and radiator cap. Use Stant or Carquest for the thermostat and radiator cap, and bump up to a 16 lb. cap to help keep the system pressurized. You will want to inspect the water pump at a minimum, but if you're taking it off anyway, you might as well replace it. Also take that opportunity to backflush your heater core.

If your temp is creeping up in traffic, that's the classic symptom of a bad fan clutch. It's a lot easier to replace that thing when the radiator is out. There are field tests you can do to see if the fan clutch is bad, but when mine went not a single one of the spin tests actually worked to detect it.

That could be a vacuum leak. The computer reads an incorrect mixture and raises the RPM to compensate. There are several fairly simple tests you can do to find a leak, some using water, some using carb cleaner, some even using smoke. There are numerous videos on YouTube demonstrating them, so search for them.