Just a quick reference.

Ive been having a/c problems over the past two summers, and at the end of last summer, I got a new compressor, and evaporator inside. Spent a nice chunk of change and its still not cold cold.

I figured I would drop it off at Nissan today and let them look at it since on the highway after driving for about 30 min, it gets cold. (Climate control on 65F, it stays at full fan the entire ride home)
They hooked it up to the machine and measured all the pressures.

AMBIENT DATA:
Ambient Humidity: 39%
Ambient Tempurature: 87 F

VEHICLE DATA:
Red Vent Temp: 82 F
Blue Vent Temp: 51 F
High Side Maximum: 183 psi
Low Side Minimum: 28 psi
Charge Weight: 1.5lbs

They are blaming the temp not being so good on the front mount intercooler saying not enough air is making it past there onto the condensor. They are saying I should install a push fan between the intercooler and the condensor. How real does this sound ??

Thanks
-matt

 

my A/C works like a champ on an untouched original cooling system and factory fans. My intercooler is fairly large also.

 

Seems to me like a lot of mechanics when they can't figure out a problem they blame it on mods. Does the intercooler even get that hot? No. What about when it is 75 degrees vs 90 and the a/c acts the same way and the car isn't even being push hard? I think those guys are just lazy. Without getting a fan you can disconnect the s/c from the intercooler and go for a ride, the charge air won't be going in so there won't be any heat, and you can check and see if the a/c feels better to you. If it does then get the fan.

 

the stealership blames everything on mods!!!!!! they just don't want to look any further!!!
really pisses me off

 

Pisses me off too. They are insisting on saying the intercooler is to blame. What is a little stupid fan going to do at 60-70mph ?? Past 30, the fan is going to be useless.

 

the intercooler will get hot fwiw...
but as the other guy said disconnect it and see if the problem is still there.
also it should be plenty cold just sitting in your driveway...

 

no problem here my air blows ice cold, it could be the filter in the line, my uncle told me one time with my other maxima that that might be the problem but i had too much freon, but he told me that there should be an inline filter somewhere in the line, check the haynes manual to see if there is one.

 

The thing that were forgetting is. Does it blow cold when your idling? My AC blows cold while idling, and theres no air coming through the condensor. Yes there is a puller fan, but honestly, its not doing that much. I am assuming you still have your stock AC Fan.

I find the AC in the 4th gens doesnt blow as cold as some of the new cars. My work car (07 Alti) blows ice cold.

 

Your low side psi seems a bit low. I would say it has verrry little to do with the fmic. Do you have a stock size UDP? A small UDP can cause this problem.

 

Stock UDP. The intercooler definetly doenst have anything to do with it. I went out to my car last night and ran the a/c for about 15 min and the A/C line going into the cabin was freezing cold and the air coming from the vents wasnt cold. Definetly somthing going on in the evaporator box, maybe a clogged expansion valve ? It is new along with the core inside that box.

 

Off topic a little, but Iansw was having trouble with a vacuum leak and took his car to a local Nissan dealer for some assistance. He disclosed all his mods, including his supercharger. When he came back to get his car, they told him he needed a new motor, and that his current one was making too much noise and must be the problem...

Yeah, Vortech V1's are kinda noisy... and the car runs fine to this day


Moral of the story: never trust the stealership with a modified vehicle.

 

Im rocking a ic and my ac runs ice cold. Mine is pretty large.

 

your low side looks good but your high side pressure should be in the 200-250 range if im correct. it seems as if its not pumping properly or something. your compressor might not be able to pump enough.


or your evap temp sensor might be freezing and not giving a reading any longer and thus why the car stops cooling. noirmally the low side will get to 32 or so and stop so it doesnt freeze anything up.

all of the turbo cars here at work have FMIC on them and they cool just fine.

 

I would also throw out checking your vent door to make sure it is closed all the way when the AC is on and not pulling in/mixing the hot outside air as the cold air is being pushed through the vents.

On my car, even without the intercooler, it works best on speed 2 or 3. It does not cool well on 4 when the cabin is really hot after been sitting. So, maybe try a lower fan speed to start off.

Plus 1 on the dealership being full of crap.

 

Did you run the A/C system self diagnostic?

When you open the evaporator box, can you see any frost? Is the thermal probe on the expansion valve attached to the freon pipe correctly?

 

Whats done to run this ?

I havent opened up the box at all. I didnt think you could without taking off the two lines in the engine bay. How is it suppose to be attached ?