Car overheats after extended hwy driving. Replaced fan & fan clutch. Still overheating! Water pump replaced last Oct, car has 115,000 mi, radiator never flushed, has original thermostat. Also, small fan (A/C fan?) next to the radiator doesn't come on while the car is running or when I turn on A/C, should it? Wasn't using A/C on the hwy because it started to overheat even at a reasonable speed (75 mph) with A/C on.

 

The smaller fan (A/C) should come on when you use the A/C. Also with my car, if i leave it idle long enough (about 10 mins) the smaller fan will come on by itself.

 

Thanks, that's what I thought. If the A/C fan isn't working that's probably why it starts to overheat when I run the A/C, except it only happens after extended highway driving. I don't have any problems around town at slower speeds. The temp stays normal even on hot days with the A/C running in stop & go traffic.

 

Change the thermostat, flush the radiator and replace the a/c fan.

Moved to N/A!

 

You answered it yourself!

Flush the system twice! Get a new t-stat, probably isn't opening like it should
get a new rediator cap.

Find out why the fan isn't coming on, it should.

Dr.

 

don't drive, then it won't overheat!

 

**Totally off topic**

Doc, where you been!?

 

Don't drive? You might as well say don't breathe!

 

I like that attitude

 

Took my car back to the shop that put in the new fan & fan clutch and guess what? The fan clutch they got from NAPA was bad! The shop manager ordered a new one (from Nissan this time) and will install it tomorrow. Told him the A/C fan wasn't coming on and he was clueless, didn't even know the car had another fan. I had to show him where it was, that's pretty scary. Told them to go ahead and flush the radiator and change the T-stat while they had it. Glad the fan clutch was under warranty! I'm glad they're replacing it because it sounds horrible, makes a loud roaring noise when you accelerate.