This is getting me completely nuts...

Bought a TL-S 6MT 3 years ago with theA/C not working. Being a mechanic myself, not afraid of wrenching, I took out the whole A/C system off the car to clean.

- Evaporator was cleaned
- New condenser
- New dryer
- Tubing/hoses were cleaned and dried
- New compressor/clutch
- New O-rings everywhere
- New expansion valve

I got it filled with R-134a

This is where the fun begins.

This compressor was making the car rumble, was whining loud and it blew in a few weeks. It didn’t explode or anything, the clutch just melted. But it didn’t seize up.

Then, I went to the junk yard and got another one. Same story. The clutch didn’t melt but heated up too much.

3rd attempt, same story.

To summarize, new parts, noisy compressor (whining) ever if it’s been replaced 3 times, excessive vibration... I have to run the system 1/2 charge to make it « acceptable ».

Pressures are OK. 30 low side and 200-ish high side. I don’t really recall but 2 A/C tech told me they were ok.

I’m completely lost on this one...

any help?

 

make sure the air gap on the clutch is set properly so you aren't melting the clutch. Are you overfilling with the PAG oil?

 

I did check the air gaps and they were all okay. One was a little wide but very close.

oil was put in by the a/c shop and when replacing the compressors after a failure, I emptied the used one and transferred the oil from the one I took out. There was very little oil in there. Not an ounce for sure

This is not something that happens over time. Compressors just whine until they fail.


Strange thing today. I blew the compressor after it’s been whining LOUD but, when I hit the a/c switch, the compressor doesn’t kick in (not turning, I checked) but the car rumbles and shakes. It wasn’t doing it before. My guess would be an idle fuel/timing mapping used when a/c is on, combined with worn out engine mounts (130k miles)

I will eventually investigate the engine mounts but a/c will be a priority over this...

 

Buy new honda pag oil, clean out the system and try again. It sounds like there is a clog in the system limiting flow. You replaced the expansion valve so the system needs to be checked thoroughly. The clutches shouldn't be melting; that means it's taking way to much energy to do the AC compressor duties on the compressor side.

Check the receiver/drier for contaminants and replace any time you open up the a/c system to make sure it doesn't go kaput again. If it has dark residue it's metallic flakes that have contaminated the system.
Put dye in the system and make sure there are no leaks/issues, checking under the dash can be fun!

Use the right amount of oil that the service manual calls for on an overhaul of the A/C system. Too little oil will fry the A/C compressor. To much oil (extra 1/2oz) will make the A/C system blow cold but not very cold until about 15 minutes for the system to catch up.

Don't worry about the rumbling, you can fix that with a few new mounts.

 

PAG oil is something I have to go to the dealer to get? I was under the impression that a specialized a/c shop would know what they were doing. I just pour all the oil
in the compressor before closing the system?

Thats what I thought too but the pressures are OK. Shouldn’t they be way high if the compressor was hard to torn and the clutch slipping?


receiver/dryer is part of the condenser and not serviceable. If my memory serves me right, the OEM was replaceable but I installed an aftermarket unit (Rockauto) when I first got the car with a compressor that had grenaded just to be sure not to have any metallic residue in there. I was disappointed to find out that the receiver/dryer is welded to to condenser.

I’m not too concerned about leaks at a/c was working during fall and worked this week. So if there is a leak, it’s minimal. It wasn’t leaking when I got it refilled as they wouldn’t have refilled it.

There was no black residue in any of the compressors I took out.

but you’re right, it really seems like the systems is making the compressor too hard to turn and the clutch is taking the beating...

 

you need to have the full amount of R134A and the proper level of oil. I'll dig up the info for the oil. Honda/Denso PAG oil is the best. Some A/C shops love to mix them and that causes issues.