Hey everyone, hope you can help. My AC belt is jumping around pretty bad and i am getting a bad vibration when i am at idle and the air is on. when i give it gas it smoothes itself out and is fine. it only does this when i turn on the air and am just idleing. without the air on it is very smooth. i have all the brackets on except for the support arm that goes from the top bracket to the exhaust manifold. i had to do away with it cause i have headers and it wouldnt bolt up. the belt is tight and maybe too tight cause i thought the belt just may be loose, but was not the case. could it be my compressor going out or what. i wouldnt think that just because that top arm is off that it would make it do this. the belt is jumping up and rubbing my upper radiator hose going to the thermastat neck on the intake. has this happened to anyone before. how do you fix it.

 

mine does the same thing... so i stopped turning on the air and i kept the windows down. thought my belt was too short but i dunno lol

 

I don't know, really, but keep an eye on it because a few years ago I had a compressor seize on me which threw the belt and toasted my engine. If the belt starts to pop off, get right on top of it and fix it right away or you'll end up with coolant flowing out of many little cracks.

 

Did you ever figure out this vibration problem with the AC on?

I'm having a similar problem. When the AC is on, and the compressor kicks in, the idler pulley starts vibrating excessively - sounds pretty bad. As soon as the compressor kicks off, it smooths right out.

I replaced the idler, thinking it just couldn't dampen the extra stress of the compressor, but this didn't help.

it feels like the compressor is out of balance or something. It does still cool ok...

It's a 91 V6...

 

Have you checked the clutch on tha a\c pulley to make sure it isn't locking up on you?

 

The AC seems to operate ok (other than the vibration)...and the vibration stops as soon as you take the engine off idle.

I've seen reports of this behavior elsewhere in this forum, so I'm starting to think this is "normal"...

My concern is that the vibration isn't going to do any of the accessories any good. I had a waterpump fail and I'm assuming that this vibration must have contributed to that.

From what I saw, looks like all I can do is make sure all my brackets are tight and solid and just live with it??

I'll double-check the clutch.

Is there any particular test to make sure it's working properly? Just make sure it spins freely when the AC is off and the AC works when you turn it on? Any other test?

 

Check your idler pulley to see if it's tension has degraded enough to allow the serpentine belt to start bouncing slightly. That probably isn't the best way to word it, but it's the best I can do at the moment.

 

If you can't figure out the vibration cause, just take the A/C out.. lots of crap off the engine.

V-Belt or Serp?

 

i havent figured it out. my air still cools but just as yours is doing, i get vibration really bad only when the compressor kicks on. i am prob just going to change the compressor. someone told me the clutch in the compressor was going bad. i will let you know what happens.

 

I suppose it could be the AC Clutch.

I have a serpentine belt, and I did swap out the tensioner and that made no impact, so I don't think it's the tensioner.

This only happens when the AC kicks in and the car is at idle. I can just run it up a couple hundred RPM and the vibration stops.

So, that makes me think that the clutch isn't locking up completely (and the AC seems to work ok the whole time).

But, I guess the clutch could be grabbing or something and more revs allow the engine to overcome that??

is there a way to test the clutch? And, is the clutch replaceable separate from the compressor as a whole?

 

i was just told by a friend of mine that i may need to oil the compressor. he said to take off the pressure lines and put a certain type of oil just for compressors. he said pour the oil in it and turn the pulley and i will hear it sucking the oil in. he said that could be the prob, no oil in the compressor. i will give it a try. will post my results.

 

Be sure to evacuate the refrigerant BEFORE popping the line off or you're gonna have a really bad day...and make certain to recharge it afterwards because empty lines will make the compressor fail eventually.

 

So how do you evacute an AC system, something I should take and have a shop do that??

My clutch froze up on the way into work and smoked real bad... So I plan on just replacing the Compressor, Can and whatever else goes with it, but working with freon itself I think I should leave to the professionals.

 

Yeah...you'd know if you had the equipment. You need to completely evacuate the lines by taking the pine pressure to -1 bar (I think) for something like 20 minutes. Then the new refrigerant is introduced into the system.

The bad day I was speaking of was if you disconnected a line full of refrigerant, you could get a really bad burn.

 

I'm still chasing this tensioner vibration when idling and the AC is on...

I had the system checked at an AC shop and they swear the compressor/clutch is ok.

they replaced the Tensioner (as I'd already done) and I'm still getting the vibration at idle.

It looks to me like the tensioner (an aftermarket without the calibration marks on it) is pretty closed to "bottomed out"...that is, it's almost completely relaxed...so I'm thinking that under the AC load, it's just enough load to stretch the belt and make the tensioner "bounce" off it's stops...could that be? Maybe the belt's stretched or it was always too long?

I think I'll try a slightly shorter belt.

Any idea what the right size would be? I've checked 3 manuals (chiltons, haynes, and a Camaro shop manual) but none give me the correct belt lengths or part numbers...

It's a 91 V6 with AC and a smog pump...

I guess I could just take the belt off, take it to the parts store and ask for a belt 1-2" shorter??

 

Quick question. Have you checked the other pulley's to make sure they are working correctly?

 

This missing bracket is most likely your problem. Without it, your compressor is not adequately anchored to the accessory mounts and will vibrate (and may be slightly out of line with the pulleys). Mr. Dude outlines a fix in here:

https://www.thirdgen.org/forums/exha...hlight=bracket