AC question on '97 Astro with 98,000 miles, 2WD

4.3 Vortec engine, original compressor. When outside temperature is about 80 degrees or below AC works great. I realize that it doesn't have to work as hard at that temperature but when it is above 80 degrees there is a loud growling noise under the hood for about 1 second after the AC is first turned on. Not sure if compressor or belt makes the noise. AC works after the noise. AC takes longer to cool the van than when new but I expected that. AC has been serviced twice, last time a couple of years ago. Was making this noise late last year so quit using it. I suspect bad compressor but holding out for a cheaper alternative.

Thanks in advance.

4.3 Vortec engine, original compressor. When outside temperature is about 80 degrees or below AC works great. I realize that it doesn't have to work as hard at that temperature but when it is above 80 degrees there is a loud growling noise under the hood for about 1 second after the AC is first turned on. Not sure if compressor or belt makes the noise. AC works after the noise. AC takes longer to cool the van than when new but I expected that. AC has been serviced twice, last time a couple of years ago. Was making this noise late last year so quit using it. I suspect bad compressor but holding out for a cheaper alternative.

Thanks in advance.
You need to get a set of air cond gauges on it and check out the low and high side operation first.
Check belt and front compresse bearing and clutch to.
MT