# 04 altima-belt flops with a/c on. why??



## altima2.5 (Feb 18, 2007)

hey guys i got a 04 altima with the 2.5 and i noticed yesterday that when i was at a stop in gear that there was a shaking vibration feeling from the engine. so i had someone put the car in gear while on the brakes and noticed with the a/c on the serpentine belt flops around all crazy, but with the a/c off its fine. with the car off i pulled the belt and its tight. whats going on?? please guys help me. thank you


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## metro273 (Sep 16, 2005)

Sounds like a "bad" belt tensioner?


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## altima2.5 (Feb 18, 2007)

but it only happens with the a/c on not all the time. and stops flopping while i am driving but at idle it flops


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## roadkill2_0 (Sep 5, 2007)

is your a/c working fine?? id think its the tensioner also


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## altima2.5 (Feb 18, 2007)

ok guys so i replaced the belt and tensioner and its still happening any thoughts? the a/c compressor turns when i flip the switch so doesnt that mean the a/c itself is good?? so when i have the a/c on and my foot on the brake when its in drive the belt flops all crazy but any other gear its just has a lil vibration but not compared to when its in drive,please help me guys its in the triple digits out here.


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## roadkill2_0 (Sep 5, 2007)

did you try replacing the belt at all??? id try that before anything


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## altima2.5 (Feb 18, 2007)

i replaced the belt and the tensioner and it does it when its in a driving gearr period with the a/c on


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## rogoman (Dec 16, 2004)

altima2.5 said:


> hey guys i got a 04 altima with the 2.5 and i noticed yesterday that when i was at a stop in gear that there was a shaking vibration feeling from the engine. so i had someone put the car in gear while on the brakes and noticed with the a/c on the serpentine belt flops around all crazy, but with the a/c off its fine. with the car off i pulled the belt and its tight. whats going on?? please guys help me. thank you


It's possible that there may be an issue with the A/C compressor or possible over-charge of refrigerant. Take the car to an A/C service shop and ask them to check the refrigerant pressures; there may be too much refrigerant in the system.


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## altima2.5 (Feb 18, 2007)

really? hows that work? ive never added any freon at all.


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## rogoman (Dec 16, 2004)

If there's too much freon in the system, it introduces a lot of drag on the compressor. If you're not the original owner, maybe the previous owner had put in too much freon.

If you've owned the car from new, then we'll disregard the freon issue.

However the compressor may still be seizing up when the A/C is turned on.

W


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## Mcmat3 (Feb 9, 2009)

*alternator bearings*

I am having the same problem... Nissan tells me that the bearings in the alternator go bad between 90-100k miles. The alternator itself is ok but the bearings go bad and cause the belt loosen or bounce a little. I'm actually having a new alternator installed tomorrow so I will let you know if it corrects the problem.


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## bob123 (Feb 15, 2009)

Any update?


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## MRPHDG1 (Apr 9, 2009)

*02 Altima with same issue...*

I've had the belt and tensioner replaced also and having the same problem. 101k miles on it. Did the replacement of the alternator fix the problem??


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## nypcdoc (Jun 29, 2009)

I am having the same issue which was discovered when changing my belt.... 05 altima with 81K miles...so far the mech is saying its the AC clutch...


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## natesimpson74 (Jul 4, 2009)

I had the same issue and it was the alternator clutch. Altimas use a special clutch in the alternator that will lock up under load when it is bad which makes the belt flop around. If it's not the altrnator I would say that the AC clutch is having the same type of issue. It is not the belt tensioner, I can pretty much guarantee this.


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## gica69 (Jul 21, 2009)

*So the final verdict?*

I have the same problem and was about to change the tensioner but now i'm reading from the ones that fixed the issue already.So the alternator and the AC clutch were mentioned,is there anymoreinput from the ones that were work in progress?Thanks guys.


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## arodery (Jul 25, 2009)

*Same Nissan loose belt mystery*

Hi,

My daughter's car has the same loose belt problem with the a/c on. Both the a/c and the alternator are expensive here in NY. Can it be narrowed down easily? Or has anyone else had this problem ?

Thanks


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## PbLead (Aug 8, 2009)

If the belt is flopping with the a/c on and in drive replace the alternator ONLY. It is the only fix. It is not a belt, it is not a belt tensioner. It is not a compressor.


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## arodery (Jul 25, 2009)

Thank you for that confirmation. I recently bought the alternator pulley and I hope to have that installed soon. I understand the one way clutch in the pulley malfunctions under the extra load of the a/c (I guess locking up) causing the problem.


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## PbLead (Aug 8, 2009)

Wait, wait, wait.... Just they pulley???? I said the whole alternator, come on now, you're gonna get yourself in trouble trying to get away with cheap fixes.


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## arodery (Jul 25, 2009)

The alternator tested good and the mechanic advised against changing it. He said the aftermarkets do not last long and he likes the oem parts (which I agree are usually better). Anyway, the oem alternators are all rebuilt and I can end up with one that has a bad pulley or about to go bad pulley on it as the dealership that rebuilds them by me did not even know there was a clutch inside of it (so would not think to test or change it). I then called Nissan and they did verify that it the pulley has an internal clutch. My understanding is that the clutch pulley is more specifically the problem...malfunctioning under extra load. I have it now and it is not returnable so I hope that does it. I know one problem may be getting the old pulley off may require a special socket. I will let you know what happens. The mechanic says he is too busy to do it while I wait so I may go to someone else. Thank you for your continued help with this!!!


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## PbLead (Aug 8, 2009)

Mechanics don't know a thing about nissans unless they have worked in a nissan dealer for years. Hell they can't even tell the difference between a crankshaft and a camshaft. They replace camshaft sensors when they have a crankshaft sensor code. They put egr valves in for egr codes when the system needs $10 a back pressure transducer valve hose. They weld on the wrong cat for cat codes when there are clearly no sensors before or after it. All they know is domestic. And it's a craps-shoot at that.


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## medina_albert (Apr 8, 2011)

i am having the same problem. the tension is fine on the belt but once i start it and place it in gear and the rpm's drop a little, the belt becomes loose. but if its in park the belt is fine. I also checked the alternator and it was fine so i was thinking maybe the a/c compressor clutch is going out. Let me know how it goes because i want to fix my problem as well. thanks


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## Chicago (May 4, 2011)

I'm having the same issue, I replaced the belt and belt tensioner, but was told by a couple of places that the belt tensioner I got was defective and that it would be best to get it directly from Nissan. I was also told it coulb be the A/C Compressor, but it seems like everytime the clutch starts to turn, that's when the problem occurs, and I was also told it could be the clutch inside of the alternator. Ill be attempting to fix this issue when I can, approaching each suggestion one by one, any help would be appreciated.


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## medina_albert (Apr 8, 2011)

i actually just changed the whole belt tensioner n it solved the problem..


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## JBrown1 (Jun 11, 2011)

Hello, I sure need some help; I have a 2005 Altima with a QR 25 DE engine. For several weeks I have had a strumming vibration develop in the serpentine belt between the alternator and the A/C Compressor. I have just rolled over 90K miles. I have installed a new belt and nothing has changed from the old belt doing the same thing. I have checked the alternator and it turns smooth and quite, no indication that bearings are bad. It has a solid pulley on the alternator. The tensioner has plenty of tension is nowhere near the mark where it needs changing. The ac compressor turns freely and is smooth by hand and operates fine. Refrigerant level is where it is supposed to be according to the gauges. I have never added any refrigerant since I bought the car new. Here is the scenario. Crank engine, RPM is 950 rpm all is quiet, Turn AC on and all is smooth & RPM drops to 750 RPM, put car in gear, rpm drops to about 600 rpm, and strumming or vibration of the belt starts. While moving out of the garage and when you speed up the vibration goes away. I have hooked up my code reader and there is no codes been thrown. Everything seems to be okay except for the belt vibration when idling. When I spoke to the dealer he did not have a clue he said, but I don't believe that. I have read several different forums and nobody has replied with anything. If anyone can help with this, it would be appreciated. From what I here there is a lot of these cars that has this problem. Thanks for your Help.


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## kaoticwarrior02 (Aug 19, 2010)

I have the same issue as well, as soon as i turn on A/C, and the car is in Drive and standing on a spot, the belt flops like crazy.. i am thinking of it could be pully, because A/C clutch kicks in fine, but the mechanic keeps saying that it is your compressor.. i think it is alternator pulley, or tensioner.. like everyone is saying here..


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