carguy987

I posted once before i tore int this a little bit. it is not the tensioner. with the A/C or defrost on. the smaller a/c tube that exits the firewall shakes and couses a very loud rumble. the location is right where you would put a gauge on it. i checked the low pressure side with one of those cheap refill kits which read, low, correct, or high, and the pressure seems to be correct. there is a newer compressor on the car. i just purchased the car a few weeks ago and do not know when the compressor was replaced, but it looks to be only a couple of month old. this is the actuall hard ac line that causes this rumble if i hold it it does not change the sound. Any ideas?????

AmarilloA4

The expansion valve is a varialbe orifice type and should have been replaced when the compressor was. (You should have a Sanden SD7 variable displacement comp. ) If the sealed capilary which drives the diaphram in the exp. valve has leaked down , the diaphram may be cycling cousing a resonance ???
The valve block is easy to replace.(about $55 or so)
Need new O-Rings and a recharge.

My 2 bits....

carguy987

whre is the expansion valve? where is the best place to get a replacement?

AmarilloA4

passenger side firewall. The 2 ridgid A/C aluminium tubes attach to the front of the block using a single bolt and O-Ring face seals.
It's been a while.... sorry, I don't remember if the valve was a dealer part or sourced along with the compressor.
I would give em a call before you go to a stealership, they were great to deal with.<ul><li><a href="http://www.aircoparts.com/">A/C Parts Here</a></li></ul>