Anyone familiar with automotive AC systems and symptoms?

[RCWD21]

I've been searching all over the place for an answer but I've never been able to find a clear answer to my issue.

 

The culprit is a ticking noise coming from the AC compressor on my 87 pathfinder. It sounds similar to the ticking noise a turbine engine makes when it's spinning up and trying to inject and ignite the fuel.

 

It ONLY does it from idle to roughly 1000 rpm and after that it doesn't make any noise except the normal click when the compressor clutch cycles on and off.

 

I've read that it could be too much or too little refrigerant, a bad pressure valve, or a bad bearing or something just completely worn out interally.

 

I can service my own system once I get the local shop to evacuate everything, and I plan on making sure the r134a swap is done correctly, I think someone only put the one adapter on to use the DIY cans and then just put the cap on and went on with it. I have a feeling that there's a mix of r12 and r134a in the system and that this is causing the issues but once I get done with it all it'll be done correctly.

 

Anyways, I hope someone can help with my AC even though it's becoming winter time lol

 

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[adamzan]

I think I know what sound you're talking about. Mine does it. I'm 99% sure its due to a slight under or overcharge on the refrigerant. I am not an AC tech by any means, but I bought a vacuum pump on amazon, and a gauge set. It isn't too hard to work on yourself once you understand. I would charge it by pressure. And remember the pressure numbers in the FSM are what it should be with the engine running at 1200 or 1500 rpm, not idle.

[RCWD21]

Well I think I may just service the system either way to make sure there's enough oil in it and to also flush everything and install a new dryer, I see some oil build up around that area and it's rusty.

 

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[PathyAndTheJets]

Mine has a slight front seal leak, and the dirt/oil combo was tapping on the pulley as it spun, cleaned it up and it was quiet.

You can tell if it's low on charge if you see bubbles or "flock" (industry term) after the compressor has been running for a few seconds. It's normal right after it cycles, but should dissipate.

 

You'll definitely want to replace the dryer, and the other O Rings in the system before you convert to 134a. The molecules are a lot smaller and tend to leak more than R12.

For a fresh charge you have to pull the system into a vacuum as well, which also doubles as a check for the seals, it should hold vacuum for at least 10 minutes, otherwise you're just going to blow the refrigerant out.

[PathyAndTheJets]

You should have the old refrigerant recovered professionally, and make sure you let them know that you suspect 134a mixed with the r12, so they don't ruin a good keg. An AC shop should have a refrigerant identifier and can confirm that for you too.

[RCWD21]

I planned on getting a spare compressor from the JY and a new dryer and O-ring kit when I get get the gauges and vac pump.

 

I know how to service the system, I just don't have a legal way of evacuating the system. The local shop will do it for cheap.

 

Are the compressors the same between the vg30i and the vg30e besides the magnetic clutch? I can't remember..

 

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Edited December 12, 2016 by RCWD21