coachholland

iTrader: (2)

I've had an issue with my Maxima since I purchased it and haven't really worried about it until now that the weather is getting warmer. I have the manual climate control and regardless of whether it is in the hot or cold position, it blows hot air. This is the case also regardless of whether it is vents, floor etc. Tried the AC today as well and the compressor does kick on and also checked PSI and it's reading around 38, so it's within spec (it's about 70 degrees here today).

Ran a search on the forums using several different keywords and found nothing in regards to anyone having the same issue I am. It was always people with the opposite problem (no heat) or a simple refridgerant issue (low PSI or bad compressor/clutch).

Not really sure what could be the problem here.

gtr_rider

iTrader: (50)

your evaporator, located behind the glove box, may be shot.

coachholland

iTrader: (2)

Would that have anything to do with it blowing hot air in the cold position (no AC on) with it 15 degrees outside in the winter though? From what I understand the evaporator is part of the AC system only, but admittedly my understanding on the heating and cooling system is limited.

Kbghdg

iTrader: (1)

Dumb question but, was the compressor running when you took your gauge reading?Also is the suction line cold?

coachholland

iTrader: (2)

Yes, both aluminum exposed lines are cold. The pressure was checked with the AC on high and the compressor was running.

Kbghdg

iTrader: (1)

Only the big one should be cold. Unless you have a restriction in the liquid line before the expansion valve.

coachholland

iTrader: (2)

Sorry, I don't know why I typed that before like that. I meant to say that I had checked both exposed lines and the high pressure was hot and the low pressure was cold. I really don't think this has to do so much with the AC system as much as something that is keeping the air from being switched from the hot and cold positions. I say this because there is *zero* difference between just the vent being run in hot or cold. It isn't just isolated to the air conditioning.

Kbghdg

iTrader: (1)

Ok, That's good. I really don't know to much about auto A/C and heating. But is it possible that hot water is going into your heating coil when its not supposed to during the cooling cycle. I think their is a hot water **** that opens allowing hot water to flow into the heating unit.

coachholland

iTrader: (2)

Ok, that's a starting point for me to do some additional research. Never even heard of anything like that, so I'm clueless what you're referring to (though I am at least familiar with the heater core, please don't let that be a problem... no way I can take off the entire dash). Thanks for giving me a little direction here. I'm heading on to bed, but if you or anyone else thinks of anything else to check as well, please let me know.

Greatly appreciated, Kbghdg.

Kbghdg

iTrader: (1)

No problem,
Since your post got my curiousity up. I went out to my max and found the valve that opens for the hot water to flow into the heater unit. It's has a cable attached to it and is located under the hood right next to fire wall behind the upper intake manifold. Check it out. It should change position when going from heat to cool. If it does not then that's your problem and it's probally stuck open.

beez5spdmax

these maximas have great ac i say get your lined flushed and refill it again with r-134 and also drain ur radatior. u know flush your radatior. good luck

coachholland

iTrader: (2)

Kbghdg, I think you may have found part of the problem. I checked the cable you are referring to and it looks like there is a spring that has come off there, it's just kind of dangling. I'm not really sure how it goes back on, so if someone could post a pic of how it's supposed to look I would appreciate it.

However, I did manually move it from the closed position to the open one and there doesn't seem to be any difference. Could you also confirm what position it is in when it is actually "open"? I'm guessing that when it is in the closed position the climate control is supposed to be on cool and when open it is set to warm.

beez5spdmax, thank you for the suggestion. I flushed my radiator about a month ago when I replaced my thermostat. I'm not sure I want to vac and fill my AC at this point because it's somewhat pricey to do so and I'm not leaning in the direction that this has to really do with my AC system at this point due to the fact that there is no change in temperature when switching between cool and warm with the AC off either.

njmaxseltd

iTrader: (19)

I believe there is a mixing door that controls air flow through the system. It directs air twards the heater core or directly at the evaporator.

coachholland

iTrader: (2)

Now that you mention that, it seems like on other vehicles I've had, there has always been an audible noise when switching between cold and warm on the climate control. I don't think I've ever heard that when switching from hot to cold positions on the Max. Is there a noise you usually hear when switching positions and is there anyway to check the air path or this door?

Snypa

iTrader: (35)

not you again......"rim or stock rim"....OMG

coachholland

iTrader: (2)

Can anyone help with anything listed in my last two posts in this thread?

coachholland

iTrader: (2)

Well, just to update in case anyone has an issue like this in the future...

Kbghdg sent me in the right direction. The valve that he's talking about is called the water ****. It is attached to a cable that goes in the firewall and is then controlled by an air mix motor which is located inside the vehicle on the drivers slide somewhat close to the PCM. The motor operates when sliding the gauge from cold to hot and a plastic arm controls the cable movement. The cable that attaches to the arm has somehow gotten disconnected and thus no movement in opening or closing the water ****. Attached that cable back (along with the spring that I had mentioned earlier that had become disconnected) and the air is now blowing ice cold.

Of course, now my compressor seems to be going out on me due to a hissing noise coming from under the hood that somewhat goes away when the compressor turns on along with some other issues that seems to have just popped up as well. I think I'm close to giving up on this one and moving on to another vehicle.

hynes66

I'm having issues with my maxima's ac too and ditto on considering a new vehicle.. but you gotta love the fourth gen maxima!!

levid2nd

My A/C blows nice and cold when the car is moving, but when I am stopped it does not blow as cold. Someone suggested that I "top off" the refrigerant. Is there any reason that I should not do that or are there any other suggestions as to what may be causing this?

Crusher103

iTrader: (10)

bigles if u dare

DrivenToTheMAX

I'm having trouble with my AC too. All of the sudden it just stopped blowing cool air. Everything seems to be working just not blowing cool air. I have a 95 Max with auto climate control.

Any suggestions?

cashoit

check belts. Re-charge system with refrigerant.

MaxiNone

iTrader: (1)

mine did the same thing, first check you fans and if they work its probably the lack of refrigerant.
read post 17...

ejumpoff

iTrader: (2)

same problem and when i turn on my a/c i feel like the enging goes down on power

worldspeaker

Hi everyone,

I also have a 98 I30 that does not blow cold air. I can't post my own thread yet (ridiculous in my opinion) so I have to ask through this post. Everything seems to be working and it registers that the r134 is at the proper level. The car has 248,000 miles on it. Can the r134 just be old and need to be replaced? Any thoughts?

Dave

ATTappman

What do you mean - "it registers that the r134 is at the proper level"? Did you hook up a manifold gauge set? What were the low and high side pressures? Does the compressor suction line feel cold when the engine is running and the AC is on?

Refrigerant doesn't degrade with time, but if somebody topped it off multiple times without purging the supply hose, you might have air in the system.

cashoit

Did u check evaporator? Have u tried the remedies in the thread? Have u checked the refrigerant pressure? Is compressor kicking on?

U have to post more info than jus "my ac isnt workin"

Swazey

if the compressor kicks on then you need to recharge the system. go to your local auto store and buy a can of that recharge refrigerant, shouldt be more than 25 bucks. i picked up some at a bennys for 20. follow the directions on the can, its fail proof.

locate the low pressure intake ac line, which is on the left side of the engine and has a little **** that is marked with a "L"

unscrew this ****, shake the can of refrigerant and attach the hose.

pull the trigger and shake and rotate the bottle while it is recharging the system.

this takes like 5 mins and you should have ice cold ac as soon as you have emptied the can.

my car sat for 2 years and the ac was blowing hot air. as soon as i did this it was blowing colder air than it had ever before.

hope this helps

najee1062

I had this problem and what I did was clean the rad in front of you car radiator... this get clogged with bugs and road crap. Take regular water hose with a nozzle attach and spray the rad that's directly behind the front grill.... problem is it's not breathing correctly.

Since I done this my AC is colder than ever, sitting still and driving

worldspeaker

The compressor seems to come on. I have attached the gauge that comes with the R134 (actually checked two of them) and they read in the normal range. Everything seems like it should need to be charged. The air comes out strong but is warm like it is low on R134. The car has 248,000 miles and has never been charged. I am afraid of putting more in and overcharging the system but it seems like that is the only thing it could be. The metal line by the Low valve is warm and the metal line by the High valve is very hot. Am I missing something?

Dave

nelledge

iTrader: (6)

'Seems'? One step at a time. Start with the basics. Is the compressor actually coming on? In other words, is the the clutch freewheeling or engaged? Guessing will cause unnecessary repairs and a huge amount of frustration.

najee1062

If you're unsure of levels of R134 than starting from scratch is the best thing... Also make sure that the compressor is working properly before even doing that.

Sirrah

That sounds as if you have a leak in the system somewhere. Check the pressure on the low pressure line, and get a small can of the leak detecter (found @ most autoparts stores). When you put it in (the same way you would add freon), you should hopefully see where the leak/hissing is coming from.

You are refering to the condensor.

najee1062

Right thanks [Sirrah] the condensor will get clogged with bugs and crap and it will not breath as it should and you will not get that cold air you should... just a thought, it solved my warm air problem... Next time you're at the car wash take the high pressure hose and spray it down. I got to mines better by taking the grill off but you don't have too.

nwo7216

i had this same issue this last winter. I replaced the thermostat

Maximas3.0

I recently bought a used maxima 2001. At the time the air conditioning was good although slow to start with than desired. One fine day it stopped working altogether. Inspite of the fact that i let it run for almost 30 minutes (hoping it would eventually kick in).
Following are the things i noticed with the a/c on (not blowing cold):
1.)Theres a clicking noise (clutch engaging, normal)
2.)The engine revs up (load on engine, normal)
3.)The Low pressure is hot (should be cold, not normal)
So i got it checked at three different local mechanics because the dealership service center is too busy to book an immediate appointment.
All three mechanics i showed the car to put the pressure gauge on the low pressure side only and said that refrigerant charge is good and the compressor has failed. To be honest i am not sure if that is the right procedure to diagnose compressor failure.
When the last mechanic i showed to said the same thing I decided to go through with the repairs with a used one (brand new is too expensive).
However, as i was about to turn off the car to leave it with him the a/c was blowing cold. Considering the mechanic's credibility was all but lost i decided against the repair to perhaps do a little more research and brought the car back.
My prime suspect now is the expansion valve and/or the thermistor. If any of you guys out there have had a similar problem resolved please let me know. Meanwhile i am going to do a little more research on the expansion valve failure and its consequences.

metalgod3082

It helps to know the exact PSI for the Low and High side. Do you have that information?

Maximas3.0

I dont have that information but i can get it maybe tomorrow.

metalgod3082

Ok just let us know when you get that info.

najee1062

My problem was I had to much refrigerant and I got a guy to remove some even though it was illegal how he did it but solved the problem. Then still It wasn't as cold as it should have been so he used a garden hose with a str8 nozzle and clean the bugs and debree from my condenser. COLD as ice was the results after that. I too thought I needed a new compressor so the mechanic told me. But somewhere in searching the forums I came across this explanation and tried it.