A/c Chatter

qristofer · June 23, 2010

This be my first on this forum and I thank everyone for you time and your help in advance. I have a 2001 Burb LT with the 5.3l motor and lately i have this chattering noise that comes on when my a/c is on. It usually happens under accel when rpms are high. It does not happen at idle though but when the compressor engages the whole burb vibrates like crazy. A/c still works fine but the noise is really loud and am not sure if its the belts or bearings on the compressor itself...Has any body had such an experience and is this something i need to take care of sooner rather than later...thanks in advance....I apologize also for the readability of my post seems there is an issue editing this post on a firefox webbrowser

zedbear · June 25, 2010

Mine is also making a noise under the same conditions except I described it as a "whirring" sound. But I guess "chatter" is also a good way of describing it. I don't have the vibration problems, though. Some people seem to think the compressor is wearing out.

Wires · June 25, 2010

If it's doing it when the AC is active (IE clutch is engaged, and it's cooling), it's most likely the bearings in the AC compressor. If the AC isn't running, then its probably the bearing in the AC clutch pulley.

I'd pop the belt of and spin things though. Could just be a loose pulley as well.

qristofer · June 30, 2010

I think the bearing in the compressor itself is shot. The a/c tensioner is also gone and that is where I suspect the vibration is coming from. I was thinking about replacing the bearing on the compressor myself, but after a little googling here-- http://flashoffroad.com/Maintenance/hvac/a...ullyService.htm and here http://www.bernardembden.com/xjs/comclutch/index.htm. It looks like this is something best left to someone that has a shop and the right tools. I just might have to replace the whole compressor.

Sir Dan · June 30, 2010

I think the bearing in the compressor itself is shot. The a/c tensioner is also gone and that is where I suspect the vibration is coming from. I was thinking about replacing the bearing on the compressor myself, but after a little googling here-- http://flashoffroad.com/Maintenance/hvac/a...ullyService.htm and here http://www.bernardembden.com/xjs/comclutch/index.htm. It looks like this is something best left to someone that has a shop and the right tools. I just might have to replace the whole compressor.

You say the AC belt tensioner is "gone" meaning the pulley bearing or tension spring is bad? I would start with repairing that before diggin into the compressor, which is nearly always replaced with a remanufactured unit vs. replacing bearings.

jblakeney · July 1, 2010

Sounds like an A/C Job will be in your future...... Compressor failure happens to everybody someday.

Jbo

qristofer · July 3, 2010

I think the compressor bearing is bad because the 'whirring/chattering' noise only comes on when the a/c is engaged and only when revs are high. I also assume if it was the pulley bearing then the noise would be constant since that belt always runs whether the a/c is on or not. I will replace the a/c tensioner and hopefully that,s how far I have to go. Fingers crossed

slamkeys · July 20, 2010

I think the compressor bearing is bad because the 'whirring/chattering' noise only comes on when the a/c is engaged and only when revs are high. I also assume if it was the pulley bearing then the noise would be constant since that belt always runs whether the a/c is on or not. I will replace the a/c tensioner and hopefully that,s how far I have to go. Fingers crossed

I've been looking into this because mine just starting doing the same thing, and yesterday my A/C belt broke. I've conlcluded that the TSB referenced here describes the problem. My Yukon has 97K miles on it, so I'd be willing to bet the compressor is the problem:

Bulletin No.: 03-01-38~019A

Date: September, 2004

TECHNICAL

Subject:

Underhood Rattle Noise Heard On Acceleration (Check A/C System Performance and Compressor Operation)

Models:

2003-2004 Cadillac CTS

2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

2002-2004 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe

2002-2004 GMC Denali, Denali XL, Savana, Sierra, Yukon, Yukon XL

2002-2004 Commercial Upfitter Chassis Vehicles

with Air Conditioning (A/C)

This bulletin is being revised to update the service procedure and parts information. Please discard Corporate Bulletin Number 03-01-38-019 (Section 01 - HVAC).

Condition

Some customers may comment about an underhood rattle noise heard on acceleration or a sudden loss of A/C system performance.

Cause

This condition may be caused by liquid slugging of the A/C compressor. This condition may cause an internal failure in the A/C compressor. The serpentine belt tensioner and serpentine belt may also be damaged.

Full document:

http://www.cadillacfaq.com/faq/tsb/data/03-01-38-019a.pdf

What I'd like to find now is a diagram showing all the components in the A/C system and how they are connected. My 2002 Yukon has rear air, and I want to replace the compressor, and if necessary flush out the system and install a new accumulator and orifice tube, but I don't have access to a manual that details the procedure. Any help appreciated.

ken1mod · July 20, 2010

I think the compressor bearing is bad because the 'whirring/chattering' noise only comes on when the a/c is engaged and only when revs are high. I also assume if it was the pulley bearing then the noise would be constant since that belt always runs whether the a/c is on or not. I will replace the a/c tensioner and hopefully that,s how far I have to go. Fingers crossed

I've been looking into this because mine just starting doing the same thing, and yesterday my A/C belt broke. I've conlcluded that the TSB referenced here describes the problem. My Yukon has 97K miles on it, so I'd be willing to bet the compressor is the problem:

Bulletin No.: 03-01-38~019A

Date: September, 2004

TECHNICAL

Subject:

Underhood Rattle Noise Heard On Acceleration (Check A/C System Performance and Compressor Operation)

Models:

2003-2004 Cadillac CTS

2002-2004 Cadillac Escalade, Escalade EXT

2003-2004 Cadillac Escalade ESV

2002-2004 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe

2002-2004 GMC Denali, Denali XL, Savana, Sierra, Yukon, Yukon XL

2002-2004 Commercial Upfitter Chassis Vehicles

with Air Conditioning (A/C)

This bulletin is being revised to update the service procedure and parts information. Please discard Corporate Bulletin Number 03-01-38-019 (Section 01 - HVAC).

Condition

Some customers may comment about an underhood rattle noise heard on acceleration or a sudden loss of A/C system performance.

Cause

This condition may be caused by liquid slugging of the A/C compressor. This condition may cause an internal failure in the A/C compressor. The serpentine belt tensioner and serpentine belt may also be damaged.

Full document:

http://www.cadillacfaq.com/faq/tsb/data/03-01-38-019a.pdf

What I'd like to find now is a diagram showing all the components in the A/C system and how they are connected. My 2002 Yukon has rear air, and I want to replace the compressor, and if necessary flush out the system and install a new accumulator and orifice tube, but I don't have access to a manual that details the procedure. Any help appreciated.

I replaced the clutch bearing on a camaro last year. It cost $4.00 for the bearing and the pullers were free loaners. About 1 hour of work. Did not discharge a/c system.

Ken

qristofer · July 25, 2010

By far the most illustrative video on changing the a/c clutch bearing is this video on you tube http://www.youtube.com/user/CoolstreamAC. An impact wrench makes all other special tools unnecessary...The compressor itself might not be an exact match to the ones found on a suburban, but it is close enough

Grebbler · July 27, 2010

Check the rear A/C to see if it still works. When the compressor was damaged due to the slugging issue, shavings or something got into the system and plugged my rear expansion valve. Now I only have front A/C, it chatters and breaks tensioners if I accelerate too fast.

I am going to see if Justin will add a throttle limit to the compressor coding in my PCM tuning as a work-around for now.

qristofer · July 31, 2010

I Just installed a new a/c belt tensioner and new gator back belt, and the chatter is gone but the whirring still persists. When I rev the motor there is no noise at all, but once I let off the gas then the whirring comes back for a sec before it quiets down. I looked to see how the new tensioner was working. It spins fine but it is really vibrating. I wonder if that's how they work. Before I put in the new belt and tensioner I spun the pulley on the compressor and the clutch and they both spin fine. No binding or grinding. I now think this might have something to do with this slugging (whatever that means) or maybe the new tensioner just does not have the right tension or just too much tension??

slamkeys · April 14, 2011

I just bit the bullet and replaced my compressor, accumulator, and orifice tube over the weekend and I'm back in business.

I flushed out the front half of the system, but it really didn't need it. The orifice tube had a few small metal flakes in it, but nothing I was concerned about for a system with 102K miles on it.

I think the TSB/slugging issue was definitely the culprit in my case. My system cools better now than it has ever since I've owned it, which tells me the compressor was already worn on the high side when I got it.

The job wasn't that hard really, and I think I spent more time running around picking up parts than I spent on the overhaul.

The biggest challenge I had was removing the sensor at the back of the old compressor, it just would not come out. The new compressor only had a plug in it, and you have to reuse the old sensor if it exists. After I removed the snap ring, I tried to jiggle the sensor out but to no avail. I finally got out my porta-band and cut the old compressor's end cap into 2 pieces (aluminum) allowing the sensor to fall right out. In hindsight, I might have been able to force it out with compressed air through the compressor inlet port - who knows.

The other gotcha I ran into was the new orifice tube was getting hung and I couldn't get it in. I don't know why but there was a nub or something about 3/4" into the A/C line that it was getting hung on. Without pulling the entire A/C line out, there isn't very much room between the opening and the firewall, so you can't even look inside without a mirror. I decided to fashion a swedging tool out of the hammer end of a small cold chisel that was close in diameter to the A/C line (I filed it until it matched the A/C line's internal diameter), and by working it around with a little compressor oil I was able to smooth the inside of the A/C line until the orifice tube slid in normally after oiling the o-ring. I flushed out the line with A/C flush and compressed air before I put the orifice tube back in.

Another potential issue you should always beware of when replacing the compressor is that the bolts are going into an aluminum block - so be careful that you don't cross-thread them when you install the new compressor. It's pretty tight down there and you won't be able to drill out a broken bolt if you break one off.

Tip: I've seen videos explaining that you have to remove the upper and lower fan shrouds (and fan) to do this job, but you don't. I was able to get the compressor out by turning my wheels all the way to the right, and working through the wheel well. I didn't even remove the plastic wheel well liner, but you could do that to make access easier. I just lifted it up a little and slid my ratchet bars through to remove the bolt at that height. The others were accessible either from above or below the engine.

Costs:

1. Compressor: $269

2. Accumulator: $50

3. Orifice Tube: $2

4. R134a (4 Cans): $48

5. Compressor Oil: $7

6. O-ring kit: $10

7. A/C Flush: $12

8. A/C Belt: $20

Special Tools Needed:

1. R134 Gauge Set (test vacuum and re-charge system)

2. Vacuum Pump (pull a vacuum on the system to remove moisture and test for leakage)

3. Air Compressor (to flush out the lines)

4. Snap-ring pliers (to remove compressor sensor at rear)

5. Offset needle-nose (to remove orifice tube)

6. Baggies and rubber bands (this is what I use to seal the lines while I have them open)

qristofer · May 29, 2011

I too just replaced my a/c compressor. Spent all day friday chasing parts down. I went to my local chevy stealership and as always they quoted me their astronomical prices for parts. Their breakdown is as follows:

19130450 Compressor 505.98

3096068 Orifice 5.40

19130064 Accumulator 64.00

12356150 Freon/ref 49.00

12378526 PAG/oil 16.84

This is what I paid

Denso Compressor 242.00

Ac Delco Orifice 2.39

Murray accumul 25.31

O-ring gasket kit 6.09

Interd pag 46 5.37

I got the compressor from amazon and the other parts from advance, thanks to their online coupons. I started by removing the compressor first, of course this is after the good folks at Meineke were kind enough to discharge my ac system at no charge. 4 bolts is all it takes. Used Slamkeys tip on turning the front wheels all the way to the right, that way I did not have to remove the tires, wheel liner, or any coolant hoses. access to the bottom bolts was easier done from underneath the veh while the top two from above. Pulling the compressor out is tough because of the lack of space to maneuver it. Removing the coolant hoses will help, but I did not feel like messing with any coolant.

Installing the compressor is also the same tight space. having a second person bolt the compressor in while the other holds it in place will make the install easier. Once the compressor is in everything else just bolts right in with no issues. Make sure to replace all gaskets (dip them in PAG oil before installation). The accumulator is much easier to remove and install because it does not require much effort. I loosened the strap that holds it in place and slid it out. Be careful not to bend your hoses. I forgot to buy a new insulating sleeve, so I just used the one from the old accumulator but with some duct tape (even though it was crumbling and falling apart).

Then the orifice, everything was going smoothly until this point, I did not have a 23mm wrench, so I tried using a 3/4 wrench on the brass fitting without holding the other side. Bad idea. The whole tubing bent upwards and while trying to bend it back in place a crack developed. I checked AdvancedAP to see if the carried the short tubing going from the orifice to the firewall, but it looks like you just cannot replace that piece by itself, you have to replace the entire aluminum tubing ($108). I will probably try to have it soldered just to save money, but its Sunday and no one is opened to recharge my system. firestone wants 132.00, while midas wants $ 178.00. I will have to wait till Meineke opens on tuesday, they only want 99.00 to recharge.

This repair was not that bad. oh yeah, pulling the orifice, its end appears as a + sign inside the tube. A pair of needle nose pliers will do the trick. I had to use a make-up mirror to see how far inside it was in the tube, but a needle nose pliers pulled it out easily.