1999 TL. 195,000 miles.

I changed the thermostat and radiator fan last summer because the car was overheating when idling and A/C wasn't working. (At least I think it was the radiator fan - it was the driver side fan.)

Now, while idling, the temperature gauge goes up to about 3/4 (in warm weather). The A/C still blows cold and it doesn't overheat. Once I start moving again, it cools right down and the gauge stays just below half way.

What do you suppose could be the issue here?

Incidentally, the radiator fan stays on for seems like a really long time after turning the car off. 1-2 minutes I could understand, but 10 mins seems excessive.

 

Mine was doing this & the issues was low coolant.

 

You need a Fan Sensor A , on 99s its located on the thermostat housing on top of engine- easy access
Buy one anywhere it doesn't matter, but when it fails the driver side/primary fan doesn't turn on when needed- so your temp rises, and it runs 10 minutes after shutdown
Every time I see those symptoms on here- fan sensor A is at fault!

 

first question I ask when a TL has overheat on here- does the driver fan run more than 1-2 minutes after shutdown- like 10 minutes???!!!

 

Rebleed the cooling system. Instructions are in your owners manual.

If condition persist then replace the temperature sensor.

When you replaced the thermostat, did you install it with the pin/vent hole on top and facing the right way?

 

Make sure BOTH fans are running whenever the a/c engages. They should spin at about the same speed, and move about the same amount of air.

 

Ok. Duh. Coolant level should have been the first thing I checked. Topped it off and it works like a charm. No more temperature issues.

Now to figure out the misfiring issue...

 

:thumbsu p:

 

misfire? you didn't mention that! Have the codes read and report back- parts stores will ck them for free
Most likely culprits: a bad coil, worn spark plugs, incorrect spark plugs (needs 8$ each NGK) clogged EGR passage inside intake manifold
Do you have spark plug wires? or the 6 coil on plug system- not sure when they changed it 99 or 00

You also need to find out WHY it was low on coolant as it should never use any- only leaks it!
Water pump is a good place to start looking with your miles, its due for 2nd replacement now
rad cap condition, loose hose clamps are other things to ck
Res bottles' cap has hose inside it = attached firmly?

 

When it's hot out my driver's side fan can sometimes stay on for ~10 minutes after shutting the car off. My car seems to be able to stay at temperature though.

 

assuming you already ckd the rad is full and fully burped, and the res bottle cap has its hose inside firmly attached THEN
Go buy a Fan Sensor A