Pavich91

Hi guys

My tahoe been makin noise when a/c is on at about 2000 rpm.
The belt actually snapped yesterday. So changed it holing was just bad belt problem. Nope! New belt makes same noise

Im guessing a/c clutch maybe?
Here is vid
IMG_3216_zps5f034dd9.mp4 Video by pavich91 | Photobucket

IMG_3215_zps858148d3.mp4 Video by pavich91 | Photobucket

84SmallBlockChevy

Probably a bad bearing in the compressor. Could cause uneven, or NO movement of the pulley. Start the truck and look at the compressor pulley. Is it moving awkwardly, or not spinning at all?

-C

EDIT: Just watched your second video again. That belt shouldn't shake at all. Definitely one of the pulleys acting up.

Pavich91

The idler pulley is the one that shakes. Maybe new idler? Would that cause that noise tho?

84SmallBlockChevy

I would doubt the idler would cause that noise, but you should replace anything that isn't balanced. It's probably a combination of two problems. Did you check if the compressor spins? You should be able to turn it if you take tension of the belt.

WarrantyWorkSucks

Look for metal shavings usually a good clue to a faulty A/C Clutch.

tech2

I would take the a/c belt off and spin the a/c tensioner and a/c compressor. Check for play and feel for rough bearings as you rotate the pulleys.

Run the engine with the a/c belt off; is the noise gone?

I use a mechanics stethoscope to isolate this type of noise.

Tensioner pulley bearings are prone to seizing up. Gm has even gone away from a/c tensioners and are now using stretch belts.

RB Auto Service

Has the A/C ever been serviced? These were very prone to oil slugging issues. Often when the A/C is serviced by someone incompetent they add a little oil even though they didn't remove any. The result is premature compressor failure. Of course even with the proper oil charge the lifespan of these compressors weren't great due to the low location and oil slugging issues. When the compressor slugs it resists turning and can cause the tensioner to bounce around and even break belts. Sometimes the oil balance can be restored and the compressor saved. Usually not though. If it does need to be serviced a specialist (either GM or A/C) is your best best as oil balance is critical on this design. I won't do one of these compressors without a full system flush so that I know exactly how much oil is in the system when it goes back together.

Pavich91

its spinning when ac is on, yes. i havent checked by hand with belt off tho.

will do, thanks!

thanks, i will check all that later!
as for running engine with belt off....the noise only happens when ac is on and about 2500 rpm, other then that it ticks at all rpm's. so i am pretty sure the noise would be gone with belt off. no?

i only owned the truck for a year, so not sure.
good info! thanks

MDTAHOE

ile In Section: 01 - HVAC

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.

Correction

Technicians are to check the A/C system performance and compressor operation using the following repair procedure:

1. Open the hood and inspect the A/C compressor for damage and to see if the compressor is seized. Verify that the serpentine belt is not damaged or missing. If the A/C compressor is seized, proceed to Step 5.
2. Perform the A/C System Performance test. Refer to the Heating, Ventilation and Air Conditioning (HVAC) section of SI. Correct any performance concerns or refrigerant leaks that are found.
3. Inspect the vehicle for other possible sources of A/C compressor noise or performance concerns. Refer to Corporate Bulletin Number 01-01-38-013 for more information.
4. After all other possible sources of A/C compressor noise or performance concerns have been eliminated, only then should the A/C compressor be replaced.
5. Remove the A/C compressor. Refer to the A/C Compressor Replacement procedure in the HVAC section of SI.
6. Inspect the transmission cooler lines for damage due to contact from the serpentine belt. Replace the transmission cooler lines if necessary.
7. Install an inline A/C system filter. Refer to Corporate Bulletin Number 01-01-38-006C for more information about A/C system flushing and filter installation procedures. An A/C system flush is not to be done unless prior authorization is given by the GM Area Service Manager (in Canada, the District Service Manager).
8. Install an A/C Suction Screen. Refer to Corporate Bulletin Number 01-01-39-003A for more information about A/C suction screen repair recommendations and procedures.
9. Install a new A/C compressor. Refer to the Compressor Replacement procedure in the HVAC section of SI.
10. Install a new orifice tube for the front A/C system. Refer to the Expansion (Orifice) Tube Replacement procedure in SI.
11. If the vehicle is a 2003 model year Chevrolet Express or GMC Savana van, the vehicle may require a new accumulator. Refer to Corporate Bulletin Number 03-01-38-016 for more information. This bulletin refers to an updated design accumulator that may improve the performance of the A/C system.
12. Install a new serpentine belt tensioner and serpentine belt if they have been damaged due to A/C system slugging or an A/C compressor seizure. The serpentine belt tensioner may have broken stop tabs and/or a missing front cap.
13. Verify proper operation of the A/C system.

Pavich91

Wow. Thanks for that reply!

I took the belt off, spun both wheels and they both spin freely. When i spin the clutch it has friction when spinning but maybe thats normal?
No metal shaving anywhere.

I still think the tensioner pulley is the issue. It has a bit of wiggle play back and forth. And moves alot when belt is on and running. Like in the vid