hello everyone i have an issue with my g37s sedan 2013
i recently changed
radiator,radiator cap,thermostat,fans,fans control module,water pump,Drive belt,
and everything is good unless u turn on ac and idle the car
when im on idle with ac car overheats (sometimes) and sometimes not however whenever the rpms start to go 900+ it starts to overheat and sometimes it doesnt (all of that with ac on only the rest is all good ) any help about that?
i feel the issue is in the Ac Compressor? so what would be the issue i literally dropped alot of money on that car and i still dont get it wheres the issue

 

Sounds like compressor overload to me, but I need more info before coming to a conclusion.
- When did this issue start occurring? Was it before or after replacing all the parts you listed?
- Were all your parts brand new or were some used?
- Did you fill up the radiator with the right coolant (50/50 mix) and correct quantity, as stated in the owner's manual (8.5 liters or 9 U.S. quarts)?
- After turning on the AC full blast, can you confirm that the fans you replaced are spinning (you should be able to hear it as they are quite loud)?
- Does your AC still blow cold, is it blowing warm air, or did it stop working altogether since the parts were replaced?
- Have you examined the cabin air filter behind the glove box? This filter tends to be the most neglected filter on these cars and if it is blocked by dirt or debris, the compressor will have to work harder to give you that cold air and it will burn out in most cases.
- What exactly did you mean by overheating? The car's engine? Are you basing this solely by looking at the temperature gauge in the instrument cluster?
- Have you noticed any funny smells or the engine losing power when you drive?
- Have you tried turning on your heater in full blast to see if this causes the temperature to go down?
- Here's a good one, did you try getting your car diagnosed by professionals before replacing the parts? If not, go do that right now

 

Good questions above. To add,

How was the system bled? Are you confident it's bled fully? Any gurgling noises when turning?

 

 

car overheats with Ac on idling more then 20-40 minutes
2013 sedan 69k miles
car never did this till recently
Onxe I turn the ac off the temp will go back down
changed thermostat & still overheated at idle with AC on more then 30 minutes
changed cracked coolant reservoir & still overheats on idle

did they ipdm test & noticed bothe fans turned on but didn’t turn on high like the YouTube video

not sure if I need new fans or fan control module
need to get a obd reader to see temperatures of radiator
can I test fans voltage to see if it’s that?

when I drive car on freeway with Ac on it’s perfectly fine only overheats with AC on idling more then 20-40 minutes
live in vegas where it gets 110 easily

any suggestions
teied to follow FSM for why it’s overheating

shojld I get new radiator cap? Fans

oniy overheats with AC onidling & the second I turn AC off - temp drops back down to normal

I’ve reburped with the lisle

 

You're asking lots from the cooling system to keep you cool while idling for extended periods of time. I wonder if there's build up in the radiator causing it to be less efficient compared to new. Was the cooling system services regularly (periodic drain/fills).

Normally with the AC on the fans kick on to keep everything cool, especially when stopped. The fact that it drops in temps when you turn the ac off suggests the added load of the AC isn't being handled. What's the diagnostic flow chart say to replace when high fan speed isn't happening (or how to test for it)?

 

Your fans are probably fine, this sounds like the fan module and being that you had a reservoir leak I'm willing to bet coolant fried the high side of the module located int the fan assembly.
Other than that the only thing I can think off is a pesky air bubble tricking the coolant temp to not trigger the higher speed of the fans.

One of the way you can check this is with a scan tool to see if the ECM is sending the High speed command to the module, if it is then the module is your problem.

 

drained & refilled coolant almost 2 years ago

weird of how I turn AC off & temp drops
thx for the help 🤙

 

thanks for the info on how to check ecm fans on high - I will check it out

 

Learn something new everyday!

 

would be awesome if we all post videos of our Gs doing the IPDM test & seeing windshield wipers ,lights , ac switch & fans - & seeing fans go from low speed to
high speed

 

Just bought oem fan control module - hope this fixes the problem

 

Bought fan module & it did not fix the problem

with fan only going on mid with the IPDM test

not sure if it’s radiator fans or the motors or fan relay

 

We’re you ever able to get the problem fix? Going through this now

 

Did you ever find the issue, im having the same problem