A/C Works, not as cold as it should be

Post by **burnout8488** » 08 Jan 2012, 18:25

Finally got my A/C system sorted within the last month or two.

New evaporator, orifice tube, dryer, low side pressure port. Clutch has been properly shimmed. The system *works* as far as I'm concerned, which I'm very happy about.

The evaporator, orifice tube, and dryer are all aftermarket from FCP Groton. The evaporator is made by Omega. It seemed quite similar to the OEM unit.

The system took 6-7 cans of R134a. It runs at 35psi and does not cycle or leak. The only problem is, the air only gets to high 40s, sometimes even 51º vent temp with the A/C compressor running. I can feel the lines getting cold, but I guess the evaporator isn't doing a great job of cooling the air?

Is there a chance that the compressor is getting tired? Would a small shot of PAG oil increase the efficiency of the compressor and give me cooler temps?

When I evacuated the system using a vacuum pump, no oil came out, however I never added any oil after replacing the accumulator back in september. I was under the assumption that it was all stored in the compressor and wouldn't come out.

Post by **rspi** » 08 Jan 2012, 19:21

I would suggest you have a AC tech drain, vac, and service the system.

Post by **burnout8488** » 08 Jan 2012, 21:05

What would the benefit of that be? I vac'd the system to 30in-hg and it held the vac for 4+ hours. What more could be left? Are there further procedures that could have been done to increase the cooling efficiency? As far as it looks right now, the system should be blasting freezing cold air based on the gauge reading, and the fact that everything is new and leak-free.

Even when the system was terribly low on refrigerant before on the old Volvo evaporator, it would blow MUCH colder air, but the system would cycle. Now that it runs 100%, it's just slightly warmer.

I just spent $80 on refrigerant, so unfortunately I can't have a tech clear out the system unless I knew they'd do something differently to make it cooler.

Nikolai808 · Post by **Nikolai808** » 25 Sep 2016, 16:40

I just posted exactly the same problem and I can not find solution to this as well. My system has no leaks now and only blows freezing cold air in the rear but in the front hot air. When my condenser was leaking and 0-rings were bad all I had to do was to fill up a I would have cold air for a day or so. After I replaced O-rings and replaced condenser there is no leaks. Compressor works as it should and all climate control functions are working at least three motors on the right side of the control unit (I took out glove compartment and checked each motor when pressing buttons on the climate control - everything is working and fan is corresponding to different speed) I had ac shop do a test and they filled up with refrigerant - everything is working but no cold air in the front - only in the rear - what is the magic here?

Post by **sleddriver** » 25 Sep 2016, 17:45

burnout8488 wrote:Finally got my A/C system sorted within the last month or two.

New evaporator, orifice tube, dryer, low side pressure port. Clutch has been properly shimmed. The system *works* as far as I'm concerned, which I'm very happy about.

The evaporator, orifice tube, and dryer are all aftermarket from FCP Groton. The evaporator is made by Omega. It seemed quite similar to the OEM unit.

The system took 6-7 cans of R134a. It runs at 35psi and does not cycle or leak. The only problem is, the air only gets to high 40s, sometimes even 51º vent temp with the A/C compressor running. I can feel the lines getting cold, but I guess the evaporator isn't doing a great job of cooling the air?

Is there a chance that the compressor is getting tired? Would a small shot of PAG oil increase the efficiency of the compressor and give me cooler temps?

When I evacuated the system using a vacuum pump, no oil came out, however I never added any oil after replacing the accumulator back in september. I was under the assumption that it was all stored in the compressor and wouldn't come out.

Interesting.......I think I remember your previous post. That's a lot of 134a. I think my '98 holds a bit more than 2 cans, which isn't even close to yours. That much diff. between '98 & 99? I don't know...

The suction line should sweat from the firewall to the dryer in warm, humid air. The pressure line should be hot (liquid) up till the orifice tube, then cold (vapor) downstream. Did you flush the lines while open? Any material in the old orifice tube? I understand this job requires quite a bit of interior dash removal. Could there be a hot damper slightly open allowing warm air into the duct? Maybe even a section of duct not tightly fitted? Do you have FULL airflow out of the dash vents?

Are the accum & dryer two separate parts on your '99? I believe they're one part on my '98. Did any oil run out of the former when you replaced it earlier? The compressor is at the lowest point I think. However, having the system leaking for awhile, then open for replacement, means some was probably lost.

Re: Weak compressor. Mine is original as well. Noisy at times. Noticed a recent shift in cooling to warmer, even after doing the zip-ties. Previous clutch gap was ~ 0.9mm or so; far out of range. Our clutches could also be worn out and need replacement. At HWY speed, with RECIRC engaged, dash vent temp is still 38°F...plenty cold. With RECIRC off, it'll rise 8 - 9°F though.

I think you can add oil through the service port, with a special tool. This is one area I've left alone even though my evap core has a slow leak. I just top up when it needs it.

Post by **abscate** » 25 Sep 2016, 17:52

If that R134A went in you are horribly over pressure. My 1999 spec is 750 g, and we use about 10 % more In cold climates like the Southern Tier.inthink the cans are usually 24 ounces net or 550g each but that depends on the can of course.

Post by **burnout8488** » 27 Dec 2016, 16:53

abscate wrote:If that R134A went in you are horribly over pressure. My 1999 spec is 750 g, and we use about 10 % more In cold climates like the Southern Tier.inthink the cans are usually 24 ounces net or 550g each but that depends on the can of course.

Just want to bring this back from the dead - yup. I had a bad compressor. No idea why I kept going after 2 cans of R134a.

I replaced the compressor, vacuumed the system down, and put in the exact spec of R134a required. Worked great and is still working perfect to this day

Post by **abscate** » 28 Dec 2016, 04:18

More refrigerant over spec will kill your compressor but it also won't give you cold air!!