Intermitant Overheating

[IHateUserNames]

I am having an intermitant overheating issue with my 1991 ix. Sometimes when the car is stationary the water tempurature gauge rises signicantly and quickly. It does so unevenly with the needle swinging back and forth, but trending upward untill I get going again.

The coolent level is correct when cold, and the water pump is less than 1 year/10,000 miles old. Thermostat was changed at the same time. I think the fan is operating correctly. This happned on a 50 degree day.

I am a little bit at a loss as to what could be causing this.

[Teaguer]

What you describe is an indication that the mechanical fan clutch could be faulty .

Even though it seems to be turning it could mostly just be freewheeling .

Try this , get your car up to temp , you can even wait until it creeps up like you mentioned , then insert a rolled up newspaper or magazine into the mechanical fans blades in an attempt to stop the fan .

I suggest the paper or magazine since you might not have experience with this and this method will not pot your appendages at risk .

If the fan slows down or stops completelt then the fan clutch is shot and should be replaced .

[strad]

I agree with above, but I'd also suspect a loose connection somewhere, because of the bouncing around you describe. Most probably it's those nuts on the back of the cluster.

With my car, there's absolutely no doubt when the fan clutch is engaged: the fan pulls a lot of air and makes a lot of fan noise when it's engaged.