Automotive Air Conditioning Information Forum

2000 Buick Century Custom. 100k miles. Purchased from a family
two years ago.

HVAC worked fine up until a month ago when driver side air began blowing not as cold as passenger side. I confirmed it was not the actuator and all online info pointed to low on freon. Took it to a trusted mechanic, he pulled vacuum and recharged (die included). He said pressures look good during vacuum.

The first day after evac and recharge cold air on both sides. Second day reverted back to driver side not as cold. Third day the compressor stopped engaging. I brought it back this morning and just got of the phone with him. He said the compressor seal seems to be the issue as he cannot find die on it (only PAG oil) or anywhere else. Freon is low again.

Since it seemed to be a slow leak prior I asked him why it leaked out so quickly now through the seal. He said that depressurization from the recharge may have increased the leak. Does this sound correct?

His recommendation is a new compressor. I asked him if it needs a new dryer and he said no, because in this case there is no internal compressor damage and no concern of blockage or system contamination. Is that correct?

He quoted $550 for parts plus labor. He said the part is $350 but I can bring my own part in if I choose. Any recommendations OEM vs aftermarket brand? Quality for price?

"driver side air began blowing not as cold as passenger side."
Usually means charge is low if blend doors etc are working properly

"He said the compressor seal seems to be the issue as he cannot find die on it"

It would seem that it is too soon to condemn the compressor.
You have a leak.
A sniffer needs to be used on all fittings, and up into the condensate drain from the evap.
Also, remove the belts and tape a shower cap around the compressor, and sniff inside the next day to see if there is a leak
The dye is older technology and doesn't always work. A sniffer is newer and better technology
Sniff on the bottom of the fittings since refrigerant is heavier than air

I wouldn't let anyone change my compressor until it had been proven to have failed in some way.

Any time the system is opened for repairs the drier should be changed

He can't find the leak, so it must be the compressor? Might be a great mechanic, but A/C work, not so much. It's not right to just assume it's wherever is hard to check.

It takes some patience and tricks to find leaks, maybe find an A/C specialist.

DetroitAC wrote: ↑Tue Jul 20, 2021 2:50 pm He can't find the leak, so it must be the compressor? Might be a great mechanic, but A/C work, not so much. It's not right to just assume it's wherever is hard to check.

It takes some patience and tricks to find leaks, maybe find an A/C specialist.

Come on! You know the best method of repair is swapping parts. You are bound to find the issue at some point.

Thanks for the replies.
Maybe he's not as trusted as I thought?

I also have my doubts it's the compressor seal as well and suspicious of his answers. I try do as many repairs myself as possible but other than replacing a compressor solenoid and adjusting clutch air-gap on a couple Honda Civics I don't have much HVAC experience.

I'll bring to a specialty shop that uses a sniffer.
Might be due to one of these issues? https://scanneranswers.com/why-is-my-ac ... -recharge/

He may very well be a good mechanic for non-AC stuff.
But AC is highly specialized and can bring a regular mechanic to his knees.
A sniffer shop is a good plan.
MVAC is no where near as easy as ppl think.......

Always best to start with a shop that is a member of the trade organization.

MOBILE AIR CLIMATE SYSTEMS ASSOCIATION (MACS)

When I picked my car up this morning I asked him if he used a sniffer and replied yes, and that's how he discovered the compressor leak. Not sure why he didn't tell me that yesterday?

I intend to get a second opinion.

Can a failing Body Control Module cause a/c issues?

Update.
I bit the bullet, rolled the dice and decided to replace the compressor based on it's age alone.
The mechanic I brought it to originally is a father and son operation. The day of testing and when I returned it for leak evaluation I only dealt with the son and he gave me the quote for part (compressor only) and labor of $550. I then asked him how much the compressor cost minus labor and he said $325. I then asked him if I can bring in my own part and he said yes, which would mean that labor only would be $225.

I purchased a new Denso compressor on Amazon for $150 which ended up costing $50 after the $100 Amazon gift for qualifying for one of their credit cards. I called the mechanic to set an appointment and this time I spoke with the father. I told him about everything his son and I discussed and then this guy said his son quoted the labor fee wrong and the new fee would be $325. I told him that he should honor his son's quote but he wouldn't budge. I told him he just lost a customer.

I then called the mechanic I normally use, absolutely trust, but doesn't have an evac and charge machine. He said he will install the compressor for $120 and I can bring it to his friend's shop within a minute drive for the evac and fill ($70) after the compressor's installed . I spoke with his friend and told him about the other shop's diagnosis of a compressor seal leak that increased after recharging/pressurizing the system. He said it's a definite possibility and that it has happened to some of the systems he has tested and worked on. I also asked him if it needs an accumulator dryer and he repeated what the son at the other shop told me...a worn seal does not cause internal damage so there is no need to replace the dryer.

Compressor installed and the system evacuated and charged three days ago. So far it's working great but it's still a wait and see situation for at least a couple weeks. $240 total for parts and labor. I will update.