Hi everyone,

I have a '08 G35x and noticed my A/C was blowing hot air. I took it to the dealer and he said I had to change the compressor because there was a malfunction in it that was causing the fuse to blow and result in the blowing of hot air. This was new since after almost three years of ownership it just started happening.

I had the compressor changed and a new fuse put in and that worked for close to two weeks. Then hot air started again but now it goes from cold to hot and eventually back. Sometimes when I get in after it was parked and the air is hot. Eventually it gets cold but that's after considerable time and I can smell the air change when it goes from cold air to hot. And I've noticed that when this happens the choice between Recirculate Air and Fresh Air auto change by themselves.

Any suggestions on why this happens, how to fix and possible costs?

Thanks and any advice is welcomed

 

An almost ten year old vehicle with parts starting to fail is not unusual.

Take it back to the dealer and speak to the service manager.The compressor may very well have been the cause of blowing fuses, however there may be another problem that caused the compressor to fail?
I hope you are using a credit card that doubles a warranty on all items purchased?

Telcoman

 

Thanks Telcoman.

Actually I had it worked on by an independent - not the Dealer - due to cost. The Dealer wanted over $2,000 to make the repairs. I had an independent do it for under $900.

Originally, when I took it to the Dealer, it ONLY blew hot air. But after the repair by the independent, it blew cold for close to two weeks and now this (cold - hot and eventually back to cold or just stays hot until I park and come back to drive).

 

I'm having the same problem on my 07 G35X. The radiator and condenser were replaced last year at Midas for about $1,500. It worked okay for a while, then started the somewhat random cold/hot/cold pattern you described. I've wondered if it is the compressor, or I read there is an AC switch that may have gone bad... Since it does blow cold some of the time (actually, much of the time...it doesn't seem like a fuse to me. Seems a fuse would shut it down completely. I had it evacuated and recharged about a month ago and it worked fine for a couple of weeks, then started up again.

I'm at a loss, and hope one of us finds an answer.

Here's my post on the subject. https://g35driver.com/forums/g35-sed...g-hot-air.html

 

Multiple problems I suppose?

http://www.nicoclub.com/service-manu..._G35_Sedan/hac

Read thru the FSM and you'll have a better ideal of the complexity of the entire system and the time involved to go thru all the troubleshooting steps and all the necessary equipment required to do a proper diagnosis.

Telcoman

 

Thanks again Telcoman.

Clicked on the link for more information but was unable to retrieve anything. Can you re-post or tell me where to find the information?

Thanks

 

when they fixed your guys ac did they replace the expansion valve ? sounds like this might be your issue

https://www.yourmechanic.com/article...e-orifice-tube

 

I'm having a similar issue that is very strange. Blows cold air great, however as soon as I accelerate vigorously, let's say to pass someone or just get around slow traffic it starts blowing hot air. The only way to fix it? Turn the car off, let it rest for a minute and then turn it back on. Voila, cold air again! I have no idea what is going on?

 

System is probably just low on refrigerant, there is a low pressure switch cutoff that will turn the compressor off (to keep it from burning up) if the refrigerant pressure drops below a certain threshold. Usually operating PSI is somewhere around 50-60psi and the low pressure cutoff is set about half if that.

If you had work done on the system then it's even more likely, getting all the leaks fixed on an old system sucks, once one o-ring goes out it's time to replace them ALL and most shops will only fix just the leaking fittings (repeat customer yeah?). I hate recommending AC Pro to folks who aren't competent with refrigerant but it would be a cheap way to check if you're low, read the instructions, hook up the bottle, the gauge will immediately tell you if the system is low.

As for the oither problem, aggressive driving killing the AC, that is partially normal function. The compressor shuts off at WOT (or close to it) since you are telling the computer you need power NOW, it should resume after you lift off the throttle though and again, that is another symptom of low refrigerant.

 

Hey everyone,

Thanks for all the input.

***UPDATE***

I took my car to another independent. (Trying to avoid the expensive Stealer I mean Dealer). They shop was rated and highly recommended with great reviews on Yelp.

They did a diagnostic, checking hoses, refrigerant level, compressor, etc. and couldn't go any further after they learned that their shop computer could not communicate with my car's computer.

Their suggestion/advice was the same as one of the other shops (Firestone to name one) I took it to. They said to take it to the Stealer - I mean Dealer.

Looks like I HAVE to take it

Pray for me.

 

have them replace the expansion valve cause thats what it sounds like ^^ both of you

 

A dealership diagnostic will probably only run a couple hundred bucks, chances are the controller is shot, perhaps the only the AC relay if you're lucky. Don't take it to the Infiniti dealer however, go to the NISSAN dealer, lot cheaper.

 

My new compressor does the same thing as far as getting a little warmer.. just got it replaced a month ago at the dealership. Don't get me wrong it never gets HOT but it is cooler when driving than at idle. It was covered under my extended warranty.. before my old compressor froze up it done it as well.. but my old compressor was REALLY noisy at times then other time it was quiet then it finally froze up. Great question! And you're correct on the dealer price. If I didn't have a warranty I wouldn't of taken it to the dealer.

 

Cleric and Ketchup thanks for the advice and info.

Regarding then refrigerant, that was replaced with the new compressor but you may be right.

I had one mechanic check it and he said the refrigerant was low so he said he drained then refilled. But when I went to the dealer several days later they said the refrigerant was low. So either the first mechanic filled it up or scammed me.

Then the mechanic that changed the compressor said he filled it up. Would be interesting to see how much refrigerant is in there now.

And regarding the diagnostic, I planned on going to the Infiniti Dealer but also considered the Nissan Dealer for precisely the same reason; cost. I'm just hoping I don't sacrifice price for good work.

Ketchup, I hope it's that simple but I'll certainly bring it up.

Thanks guys!

 

any update on this ?