A/C Compressors

[DMCMW Dave]

Well it might not be the bearings but worse. I can turn it but not all the way around part way you can hear a little click then dead stop.

Broken internal parts (the compressor equivalent of a broken connecting rod). Time for a replacement.

[content22207_2]

The A/C compressor is pretty rugged. It dies because of abuse.

Not always -- they also die because the front seal wears out (just like a water pump, crankshaft, or axle seal wearing out). No abuse -- just lots and lots of use (shaft spinning in the seal). Has happened to me twice over the years.

Just like a water pump weeping coolant, the compressor weeps oil and refrigerant out the front. Tell tale sign is a band of oil slung against the driver side pontoon and across the engine cover. And you keep losing freon.

Bill Robertson
#5939

[Henrik]

Broken internal parts (the compressor equivalent of a broken connecting rod). Time for a replacement.

Yes, if those are the symptoms then it's due for an immediate replacement. Once a compressor goes - it GOES and may shoot crap all throughout the system.

[Bitsyncmaster]

A/C bearings went out, squeal smoke and looking at the sd7 or sd508 compressors. Looking for the least drage on the engine. Any thoughts or piont outs to other posts?

Thanks Dave

I've been using an SD5H14 for 8 years and it seems to work fine. It has a little less displacement so less engine load. I still get 42 deg. most of the time from the center vent. I run R134a with PAG oil. I had to swap the back plate from the original compressor.

[Henrik]

... so less engine load.

On that subject, my VR6 engine just happened to be equipped with Sanden's variable displacement compressor, SD7V16. An excellent pump that we developed mainly for VW during my Sanden years. This compressor has the advantage of a) no clutch cycling and b) optimal (minimal) engine drag during low load conditions due to the fact that it automatically adjusts to a lower flow rate.

It's entirely possible to use this compressor on the PRV but I doubt it exists with a V-belt clutch and a QD head. Not sure if it exists in ear mount config either. Some research required.

[Chris4099]

I've been using an SD5H14 for 8 years and it seems to work fine. It has a little less displacement so less engine load. I still get 42 deg. most of the time from the center vent. I run R134a with PAG oil. I had to swap the back plate from the original compressor.

I've been using this compressor as well (from specialtauto.com) and am very happy with it. It is slightly less powerful, but still capable of cooling the interior. Just has longer cycle times with less drag on the engine as well. Between it and the low current fans, there is no impact on the feel of the car while driving. I have to use a monitoring light I set up to tell when it's actually cycling.

[dn010]

Off topic a bit, what would be the symptoms of a VOV installed the incorrect direction? I'm having a bit of compressor issues and am wondering if that could be a cause.

Edit: I guess it would be nice to describe my issues - compressor will work fine and air will be cold with low amount of R134. When trying to top off to proper amount, compressor clunks/chugs and it WILL stop the engine if I keep trying to put the correct amount in. I did empty/fill it with the correct amount of Ester oil prior to filling with refrigerant. This is the stock compressor and I never had issues prior to this.

On that subject, my VR6 engine just happened to be equipped with Sanden's variable displacement compressor, SD7V16. An excellent pump that we developed mainly for VW during my Sanden years. This compressor has the advantage of a) no clutch cycling and b) optimal (minimal) engine drag during low load conditions due to the fact that it automatically adjusts to a lower flow rate.

It's entirely possible to use this compressor on the PRV but I doubt it exists with a V-belt clutch and a QD head. Not sure if it exists in ear mount config either. Some research required.

[SS Spoiler]

Are you putting in liquid or gas?

[content22207_2]

Are you adding the freon as a gas or as a liquid (can/canister right side up or upside down)? Adding as a liquid is hard on the compressor -- it's designed to pump gas, not liquid.

Bill Robertson
#5939

[Bitsyncmaster]

Off topic a bit, what would be the symptoms of a VOV installed the incorrect direction? I'm having a bit of compressor issues and am wondering if that could be a cause.

Edit: I guess it would be nice to describe my issues - compressor will work fine and air will be cold with low amount of R134. When trying to top off to proper amount, compressor clunks/chugs and it WILL stop the engine if I keep trying to put the correct amount in. I did empty/fill it with the correct amount of Ester oil prior to filling with refrigerant. This is the stock compressor and I never had issues prior to this.

I tried the VOV in my DeLorean and because of a bend in the pipe where it installs and it made the VOV valve fail closed.