I have an 03 sedan that is overheating when it sits at idle for about 10 minutes. I checked it yesterday with an OBD2 scanner to try and see what is exactly going on. For the most part it idled fine and the AC was blowing cold at full blast. Then after about 10 minutes of sitting that temp needle started to rise, the AC started blowing warm, and the idle dropped. While it was running good the idle was at 850 and the temp was ~190. When the needle started to rise the temp rose to 228 and the idle dropped to 450-500. The engine acted like it was going to stall as well. If I rev the motor up it will slowly cool it back down and if I start moving the temp instantly drops back down to normal. Also, not sure if its related but when the AC is on I hear a knocking sound from the engine bay, could be related but could be a separate problem.

I just checked the fluid and its topped off and free of air bubbles. I haven't cleaned the rad or condenser yet, (waiting on the weekend for that). I am suspecting that the clutch fan isn't spinning fast enough to cool the engine, but would that fan cause the rpms to drop like that?

What I would like to do is eliminate that clutch fan and install an e fan. Looking at the oem fan on my wife's FX it looks like a direct bolt on conversion but I dont know about the wiring. Everything I have searched for talks about adding aftermarket fans but I want oem. Does anyone know what the wiring conversion would be like?

 

Have you read/followed the troubleshooting steps in the FSM?

http://www.nicoclub.com/FSM/G35/Sedan/2003/co.pdf

See page CO-7 OVERHEATING CAUSE ANALYSIS
PFP:00012
Troubleshooting Chart
ABS0001H

Telcoman

 

Are the fans spinning? WHen your turn your AC on the fans should automatically go on...

 

Your fans are broken, Im willing to bet. A set of replacement fans will fix you right up

 

The fans are spinning. I got a new fan clutch too. I'm thinking it's an airflow problem. I'm going to flush the radiator and remove it so i can clean the junk off the outside and off the ac condenser. Hopefully that will fix it.

 

HOW DID YOU FIX THE PROBLEM? I HAVE THE SAME ISSUE, BUT AN 2004.
Vijay

 

Start by pressure testing the coolant system AND the cap, next check for proper fan speed operation, if it passes then test the thermostat opening temperature, if everything else checks out then replace your radiator.

 

And it that doesn't solve the problem replace the water pump and if that doesn't solve the problem just replace the car

 

Never underestimate the power of "replace the entire car". Guaranteed way to fix the problem.

 

A brand new vehicle comes with all new parts, a warranty, lots of new features and a loaner vehicle from the dealer if its ever needed

 

Thanks