A/C Compressor Done for?

Symptom is that the A/C doesn't blow cold, feels cool, but not early as cold as it should be.

First thought was that there is small leak and I'm low on refrigerant.

I thought I'd just try the cheap route and buy an R134a refill can.

PSI from system reads about right, 55psi according the can when 90+ ambient temp, but it is not steady.

The compressor kicks on and off rapidly...on for a few seconds then back off, pressure spikes when compressor goes off.

I may already know what I need to do, but just though I'd see if anyone had a similar problem.

This is on a 2nd gen 6cyl FYI.

 

I had a similar situation with a Dodge Nitro I used to own. I brought it to the dealership and they wanted almost $3,000 to fix it. I used one of those refill cans and PSI was all over as well. Filled the system until the can meter stabilized and it blew cold air for the rest of the time I owned it.

 

Thanks.

PSI has seemed to stabilize when the compressor is on, but it keeps kicking off every few seconds causing the PSI to spike.

I'm hoping I don't need a compressor... going to see if running around this afternoon makes any change. It's not unbearably hot with the A/C on, but it is on max and should be much cooler.

 

I just got all my parts to replace my compressor. The failure symptoms usually include cool air on the driver side vents and progressively warmer air on the passenger side as the expansion valve begins to get plugged with debris from the dying compressor. Better to take it to an expert to check the r134 level rather than keep adding refrigerant as that can also cause it to fail. Could be as simple as a relay dying and triggering the on/off cycles. You can get the condenser, compressor, expansion valve, flush fluid and flushing kit for less than $400 if you want to replace the parts yourself and then get it charged by a pro.

 

Those freon cans are terrible. Pay a mechanic to properly evac and recharge the system. Don't buy cans!!!!!!

 

Flushing doesn't work for modern condensers. The passages are too small. If you have a catastrophic compressor failure, it's best to replace the condenser. Your never gonna get it clean and your just inviting failure for the new compressor.

 

Fast cycling on/off typically does mean the refrigerant is low.

 

From what i've learned about A/C is to have the pro's do it. I shot the parts cannon at my old Honda on this exact same issue and got nowhere, ended up replacing Compressor, Pressure switch, freon, receiver/dryer etc. roughly $600 in parts.
I think I had a clogged condenser or something, never did figure out the real culprit since I totaled the car soon after.

 

I've seen weak clutches do this also. I have also seen a failing pcm do this too. But fast on and off typically is a low charge due to the low pressure cut off switch doing its job.

 

It can mean just the opposite - system is overcharged. Not saying it is - just saying that short-cycling is sometimes the result of overcharging.

I'd trust a NOLA hooker with my wallet B4 I'd believe a reading produced by a suicide recharge kit.

 

Interesting, thanks for the input so far.

Just got back from driving around in 95+ weather, seems to be cooling a little better. Compressor still quick cycling though. Freon can has a gauge that can be used separately from the can. Tested the pressure when I got home and it looked pretty good. I don't trust the cheap gauge 100%, but it seams to be ok. I'm hoping I was just low on Freon, maybe a small leak somewhere.

If this didn't fix it, I'll have a mech take a look.

 

@danbow

Similar happened to me- on my 2014 just a couple weeks ago.

Small leak of coolant. Dealer put a dye in the coolant to detect leak. Found leak and debris/metal shavings. Replaced everything from compressor to dash vents- under my 36 k warranty. Had to take back 2 days later due to faulty O rings/freon leak. Good to go now; quiet and cold!

 

You need a proper manifold/gauge set, --the low pressure side is just 1/2 of the story.

The pressures should be as indicated in this table:



If not use this table to determine the likely cause:



If it's overcharged make sure no one is watching when you vent it...

 

Coolant or refrigerant (freon) 2 different things

 

Whatever makes it cold...?

 

Coolant is antifreeze. That goes into the engine cooling system. Refrigerant is for the ac

 

Most leaks are from the Schrader valve. It's like the valve stem on a tire where you fill the refridgerant. Put a little soapy water on it and look for bubbles. Kinda OT but something to look at before a shop tries to rip you off. Easy fix too, only a couple bucks from parts store.

 

If you open up the system you will need to apply a deep vacuum to remove all the air and moisture before charging. Unless you have a vacuum pump or a recovery unit this is not reccomended to do at home.

 

To replace the Schrader valve(s) you will need to vent the refrigerant--so you'll need both a real gauge set and a vacuum pump ( ) to recharge it.

Do NOT leave the system open for any longer than absolutely necessary to actually change the valves...

 

Beat me to it...