What causes low refrigerant? No leaks and an entirely new AC system

[wydget]

And by new, I mean brand spanking new compressor, fans, fcm, and everything else needed. I got all this done in September '11. Fast forward to now, we have had intermittent problems with it cooling great to no cold air period. Just picked it up from the dealership because we were fed up with the issues and had them do an AC system check. Everything was still working correctly but they said the refrigerant was low. They told me that the aftermarket fans could possibly be drawing more amperage that is causing the refrigerant to get used?? It doesn't make sense to me, but then again, I don't know anything about AC systems. Is this possible or could it be something else. There are no leaks anywhere in the system. Thanks in advanced for any help.

 

[gquenstedt]

They told me that the aftermarket fans could possibly be drawing more amperage that is causing the refrigerant to get used??

HA! Did they really tell you this or are you inferring from something else they said?

 

[Genesis]

ROFL!

Refrigerant is not "consumed"; the only way it leaves the system is intentionally or via a leak.

 

[wmgeorge]

I would think twice about taking it back to those clowns. Intermittent cooling is not caused by low charge. Its either an electrical control problem as your compressor clutch is not being powered on, OR you have moisture in the system and its freezing at the expansion valve internally of course. If they did not change out the dryer and pull a good vacuum on the system that would be the cause of the moisture. Made a very good living working on commercial HVAC/R equipment. Car AC is not rocket science... refrigerant used up. Yeah sure.

 

[wydget]

HA! Did they really tell you this or are you inferring from something else they said?

They really said this. It was written on the work order. I'll see if it's written on the receipt, if it isn't I'll go pick up a copy tomorrow.

 

[Busted]

ROFL!

Refrigerant is not "consumed"; the only way it leaves the system is intentionally or via a leak.

This is a sealed, closed loop system. Refrigerant is turned from liquid to gas, to liquid, to gas, etc. The only "consumption" of refrigerant would be from it venting outside the system, either by a leak or someone letting it out.

 

[40X40]

So there are no leaks, but the refrigerant that was full is now low.

How exactly do you think this has occurred?

Bill

 

[wmgeorge]

So there are no leaks, but the refrigerant that was full is now low.

How exactly do you think this has occurred?

Bill

How are they checking the charge level? Do they have gauges on both sides of the system? If you recover the system and recharge with a measured by weight does if work ok?

Refrigerant can only be lost via a leak. Just because you can't find the leak does not mean its not leaking. In the past I have used electronic leak detectors some. are not worth even turning on. I have used florescent dye and black light.

If you have checked all the fittings and connections with a soap and water solution and found nothing, then the leak could be in the condenser or evaporator, tubing or a hose. Has anyone checked the condenser for damage from a rock or other?

 

[jetta 97]

They told me that the aftermarket fans could possibly be drawing more amperage that is causing the refrigerant to get used??

This is funniest thing I ever heard
I can not believe what kind of morons they hire to work in dealer.

 

[wydget]

How are they checking the charge level? Do they have gauges on both sides of the system? If you recover the system and recharge with a measured by weight does if work ok?

Refrigerant can only be lost via a leak. Just because you can't find the leak does not mean its not leaking. In the past I have used electronic leak detectors some. are not worth even turning on. I have used florescent dye and black light.

If you have checked all the fittings and connections with a soap and water solution and found nothing, then the leak could be in the condenser or evaporator, tubing or a hose. Has anyone checked the condenser for damage from a rock or other?

How they checked it, I honestly don't know but this is the 3rd shop to look at it and tell me there are no leaks. I know that one of the previous shops used the dye and black light method and hasn't discovered anything. I don't know if the condenser had been looked at but the dealer did, or was supposed to do a full inspection on the AC system. I will get under the car this weekend and take a look at it myself, after I repair a ripped fuel line on my other car.

 

[wmgeorge]

How do they explain where the refrigerant went? Or maybe it was working fine when they checked?

 

[wydget]

They couldn't tell me what happened to the refrigerant. I asked. They just repeated that the aftermarket fans could be drawing in more amperage and it was causing problems with the AC system. When I took it in, the AC was definitely not blowing anywhere near cold.

 

[wmgeorge]

I'd guess it does not have a low charge. Did you watch them add refrigerant?

If not see my answer above as to moisture in the system or a control problem.

 

[wydget]

No, unfortunately I did not watch them. I dropped it off and had them work on it.

 

[Cogen Man]

As all above have stated. Their explanation is NUTS. If they said the refrig. charge was low then either there is a leak or they never charged it with the proper amount in the first place. The too much amp. draw is crazy. You need to get it to a good auto AC shop. Unfortunately you seem to be having a rough time finding one with 3 shops having looked at it. All 3 said couldn't find a leak ? If that is in fact true, then it's either a component or electrical. wmgeorge's mention of moisture in the system with an improper re-charge is valid. Not replacing the dryer and pulling the proper vacuum and you might as well not even proceed with the re-charge.

Correct me if I'm wrong but isn't the condenser located behind the radiator ? This would make it harder for a stone hit to punch a pin hole in it. But it does happen. When you get under it look for any spots on the condenser where a piece of metal might be rubbing on the condenser. The aluminum is very soft stuff and it's easy to rub a pin hole in it. This would of coarse mean ALL the charge would leak out. No workey at all. To bad you don't live near wmgeorge, he'd have her troubleshooted and working in no time.

 

[BobnOH]

]. .... or they never charged it with the proper amount in the first place. ...........

yea that sounds about right, the bit about the fans is bogus

 

[wydget]

Here is the diagnostics part from the receipt..

 

[40X40]

Here is the diagnostics part from the receipt..

Well this explains part of it. They DON'T claim that the fans caused the low refrigerant levels. They don't claim to have NOT found any leaks.

They evacuated the system, refilled it and then it worked fine while in their shop.

Bill

 

[wydget]

Well this explains part of it. They DON'T claim that the fans caused the low refrigerant levels. They don't claim to have NOT found any leaks.

They evacuated the system, refilled it and then it worked fine while in their shop.

Bill

When the service manager called me back, she advised me that they did not find any leaks in the system. She also advised me that what could be causing the low refrigerant, which is what they found, could be the aftermarket fans. She told me the exact same thing when I went to pick it up. I asked her what could be causing the low refrigerant levels if there were no leaks. She stated that it could be the fans and to keep an eye on the refrigerant levels.

 

[jetta 97]

When the service manager called me back, she advised me that they did not find any leaks in the system. She also advised me that what could be causing the low refrigerant, which is what they found, could be the aftermarket fans. She told me the exact same thing when I went to pick it up. I asked her what could be causing the low refrigerant levels if there were no leaks. She stated that it could be the fans and to keep an eye on the refrigerant levels.

Just drive it till it stat not blowing cold again. If you can not find leak anywhere then most likely Evap Core has small hole and leaing freon out. I have seen this before that you can not find dye mark anywhere you look , open Evap Case and lot of green dye in it.

 

[migbro]

When the service manager called me back, she advised me that they did not find any leaks in the system. She also advised me that what could be causing the low refrigerant, which is what they found, could be the aftermarket fans. She told me the exact same thing when I went to pick it up. I asked her what could be causing the low refrigerant levels if there were no leaks. She stated that it could be the fans and to keep an eye on the refrigerant levels.

In other words, the service manager, who just happens to be female, is totally clueless. She was bull****ting you based on her lack of understanding of the problem and what was done.

The work order is appropriate. They evacuated and recharged the system. They also commented that your aftermarket fans may be drawing too much current. This comment is unrelated to your AC problem, though the service manager, who just happens to be female, didn't realize this and improvised her bull**** to include this observation.

 

[40X40]

Service 'manager' does not equal service 'advisor'.

Another thread where the story just gets stranger and stranger....

Bill

 

[TDI-JAY]

So glad I can run an A/C machine myself!

Pressures to high or low can make a huge difference - as long as they put dye into the system when they re-charged it like previously said drive till the A/C stops working and get out the UV light.

750 G +/- 50g or 1.65 Lbs of R134a & your good as new. Only reason I knew that was the trusty sticker on the radiator support of my car!

 

[mk3]

out on a limb a little bit.... is there a pressure relief valve on the case of the AC pump for emergency venting? I think there is and furthermore I think there is a sticker over it. If it has blown out the sticker would be loose or gine.

however, I also think the AC system has a pressure sensor in it and might just be smart enough to cease operating before overpressure is reached.

overpressure could possibly occur from inadequate cooling of the condensor????

just thinking out loud a bit.

The rest has already been stated correctly by the previous respondents.

 

[wmgeorge]

Years ago you did not need to worry about a pressure relief plug or valve. The hoses would blow up or come apart on high pressure. Things are better now. Yes the system has a High pressure switch or sensor in this case that turns the compressor clutch off in high system pressure. The plug or relief is set really high, can't recall the setting right now but around 500 psi. Yes those can be faulty venting at high and normal system pressures and you can lose refrigerant. We used to put a plastic cap or tape over so we could see if was leaking.

Since the car is running when these are leaking, hard to find the leak with all the air blowing around. I always use bubble soap made for leak detection to pinpoint leaks.

 

[KLXD]

Could be the pump shaft seal. You won't see dye unless it runs down from behind the clutch. A Good sniffer will find it if they used one.