Automotive Air Conditioning Information Forum (Archives)

Kojackisback on Wed August 10, 2011 6:55 PM

Year: 2000
Make: Chev
Model: Suburban
Engine Size: 5.3
Refrigerant Type: r134
Country of Origin: United States

AC blowing cold when belt is not broken; broken 5 belts since last Aug; noticed truck shakes at idle when ac is on; replaced belt tensioner last week at suggestion of parts store. broke tensioner off completely, replaced it with another new belt and tensioner, broke again today. with ac engaged between 1600-2000 rpm the tensioner violently shakes(that is what breaks it) original gm tensioner was pretty beat up I assume it was better build since just the belts have been breaking. last year went to have new ac put in the truck, they said just a broken belt, they evacuated the system added oil and recharged. car still shook at idle with ac on and now that I know what the noise was I was hearing I would say that it has been doing this for a year or so and only breaking belts. in the morning when it is not so stinking hot I did not hear the tensioner rattling as much. last night I removed the clutch plate to check the clutch bearing. bearing smooth and tight no noise at all put it back together with new tensioner, ( that just broke) with new belt and blew ice cubes till this afternoon when the cheaper tensioner broke. What is happening? do not know the pressure readings i have front and rear ac . I find it hard to believe the compressor is faulty and still blowing cold, for a year, something else is happening.

bohica2xo on Wed August 10, 2011 7:14 PM

Ah, the old 1800 rpm belt dance. it may be hard to believe, but yes it needs a compressor. You have changed the tensioner, and several belts. That leaves the compressor.

HERE is a thread about the same thing, with a video of what is happening.

If you keep putting belts on it,waiting for the compressor to grenade - the repair price just goes up.

B.

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

JJM on Wed August 10, 2011 7:27 PM

Go to your GM dealer give them your VIN and let them get you a proper OEM tensioner and belt, and toss the crappy auto parts store junk in the trash. If the problem is still there, as Bohica said, probably time for a new compressor as well.

Joe

Kojackisback on Wed August 10, 2011 8:26 PM

kind of what I figured, i was hoping someone would pull a miracle out of the air but with 325,000 miles on the truck and still original ac unit ( i believe, have had the truck since 89k) I can't complain. any recommendations on the type of compressor, go back with delphi or is there a better unit. I did also notice the mileage dropped some once the ac unit started the shaking some time back, it just wont blow up.

GM Tech on Wed August 10, 2011 9:00 PM

Nice video!

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The number one A/C diagnostic tool there is- is to know how much refrigerant is in the system- this can only be done by recovering and weighing the refrigerant!!
Just a thought.... 65% of A/C failures in my 3200 car diagnostic database (GM vehicles) are due to loss of refrigerant due to a leak......

chris142 on Wed August 10, 2011 9:51 PM

325K is great! Most of those compressors are blowing belts off by 90K.