[VeloTime]

So, it's been hot here and my AC was only blowing partially cold air out of the passenger side vents, warm air out of the rest

Sounded like low R134a to me.

They dilemma. I have buddy in a shop that could do a Evac/refill and vacuum test for a good deal. But, the car is CPOd, so if they did find a leak I would want to take it to BMW to get the leaky part replaced. Since it was probably low on R134a and it's a sealed system there is most likely a leak somewhere. After speaking with the owner of my buddies indy shop we all figured just going to BMW was the best bet.

Got the call this morning that it was in fact low but the vacuum test came back good and no dye was found anywhere with the UV light. I had a feeling this might happen. Looks like i'm paying stealership price $320 for the ac evac/refill, not a $50 co-pay.

Here's the kicker. It wasn't just slightly low. There was only .35lbs left in the system. This is a 1.5 lbs system.

To me that sounds like a lot to chalk up to normal loss in the system. What do you guys think? There's got to be a leak somewhere right? Is there an amount of loss noted in any tech manuals that is listed as acceptable?

This is a 2009 328 E91 xdrive with no HVAC work noted in any of the BMW service records.

In their defense, the SA did tell me to swing by in a couple weeks and he would have a tech pull it in and check with the UV light again. I will also be doing that myself.

What's the verdict? Screwed, normal?

It is blowing nice and cold so at least I have that going for me

[Titanium3er]

I'm no expert, but that sounds like a very large loss of fluid for a closed system. Did you ask the dealership where all that refrigerant could have gone? I'd be interested in hearing their explanation.

[BavarianFanatic]

If it's a slow leak (likely) it won't immediately be evident with the UV light. I suspect that now that it's fully charged, there's a chance it will probably pick up the pace and there may be signs when you do take it back.

As an aside, it's possible the evaporator is leaking which is impossible to visibly inspect (buried in the dash). I suspect that after a period of time there would be residue on the condensate drain line if the evaporator is indeed leaking.

Did you find out if you'd be compensated for the work if they determine at a later date that there IS a leak? I suspect you would be. I don't fault them for charging for the work in the absence of an obvious fault. Joe Customer could easily release some gas either intentionally or unintentionally. I think they're going about it properly.

[BavarianFanatic]

Originally Posted by Titanium3er

I'm no expert, but that sounds like a very large loss of fluid for a closed system. Did you ask the dealership where all that refrigerant could have gone? I'd be interested in hearing their explanation.

It's a gas at atmospheric pressures and temperatures. Colorless and odorless.

[Titanium3er]

Originally Posted by BavarianFanatic

It's a gas at atmospheric pressures and temperatures. Colorless and odorless.

Liquid or gas aside, how would that much escape without a leak? Like I said I'm no expert; just interested in knowing.

[BavarianFanatic]

Originally Posted by Titanium3er

Liquid or gas aside, how would that much escape without a leak? Like I said I'm no expert; just interested in knowing.

It actually CAN'T escape the system unless there's a leak. Or some yutz releases it via the service ports (schrader valves).

[VeloTime]

Originally Posted by Titanium3er

I'm no expert, but that sounds like a very large loss of fluid for a closed system. Did you ask the dealership where all that refrigerant could have gone? I'd be interested in hearing their explanation.

I did ask that very question. He didn't have any explanation except that he has seen it before. I also pushed it a bit more and asked that if this is in fact an acceptable amount of loss that this happens all the time right? He didn't really answer that directly just that it's not something they see often.

If it's a slow leak (likely) it won't immediately be evident with the UV light. I suspect that now that it's fully charged, there's a chance it will probably pick up the pace and there may be signs when you do take it back.

This what I'm hoping for as well.

As an aside, it's possible the evaporator is leaking which is impossible to visibly inspect (buried in the dash). I suspect that after a period of time there would be residue on the condensate drain line if the evaporator is indeed leaking.

I have heard of the $4k job and was one of the reasons I ended up going to BMW. I am slightly concerned that if they don't find a leak and it ends up being the evaporator I could get bitten by this post CPO.

I did bring up the evaporator and he mentioned that they do look in the vents with the UV but that doesn't seem like a very fool proof troubleshooting technique to me. I'll make a note to keep an eye on the condensate drain line.

Did you find out if you'd be compensated for the work if they determine at a later date that there IS a leak? I suspect you would be. I don't fault them for charging for the work in the absence of an obvious fault. Joe Customer could easily release some gas either intentionally or unintentionally. I think they're going about it properly.

The SA said that he would contact BMW about compensation if they do find a leak when I come back, but that cannot be guarantied. I would think they would though. That would be pretty poor customer service if not...

I do think they are going about it properly as well. I don't think they're maliciously saying there is no leak or that they didn't troubleshoot it properly. In his defense the SA didn't seem like he was trying to hose me over or anything. Just that the data provided din't really add up.

As someone else asked. I'm no expert either and that just seemed like quite a bit of gas to leak out under normal circumstances.

thanks

[J02 335i]

Standard practice at my shop would be to pressure test the system with nitrogen if the system was that low. Using vacuum as method of leak detection will only show a very large leak (in my experience). Secondly why were they looking for dye in the first place, if the system has never been worked on before? They do not come with dye in the system from new, not that I've ever heard of.

This almost sounds like a way to get some cash out of you before the "big hit" they will take on the cpo repair.

[Dark_Knight_335]

That's cold man!

[BavarianFanatic]

Originally Posted by J02 335i

Standard practice at my shop would be to pressure test the system with nitrogen if the system was that low. Using vacuum as method of leak detection will only show a very large leak (in my experience). Secondly why were they looking for dye in the first place, if the system has never been worked on before? They do not come with dye in the system from new, not that I've ever heard of.

This almost sounds like a way to get some cash out of you before the "big hit" they will take on the cpo repair.

I'm sure they put dye in while filling and checked for leaks afterward. And odds are it's a really small leak. It's just easier to check for traces of dye in a couple of weeks than to take the time to hunt around for nitrogen now.

[J02 335i]

Originally Posted by BavarianFanatic

I'm sure they put dye in while filling and checked for leaks afterward. And odds are it's a really small leak. It's just easier to check for traces of dye in a couple of weeks than to take the time to hunt around for nitrogen now.

He said they looked for dye before re-chargong the system, I realize its easier, but easier is not always the best or right way to do things.

The system should be nitrogen tested and the leak found and fixed properly. They are prolonging a problem imho.

[Efthreeoh]

Problem is it could be a leak in the evaporator, which unless they pulled the center console they'd not see it.

[J02 335i]

Originally Posted by Efthreeoh

Problem is it could be a leak in the evaporator, which unless they pulled the center console they'd not see it.

Very true but, they either do it the first and find the source of the problem the first time or prolong it until his warranty is over, then guess who gets the bill and the previous bill to re-chagre a leaking system, which it pointless.

[#Tee]

I agree with BavarianFanatic, ive personally evac/charged ac systems before and used dye to detect a leak. My experience was NO leak found on the initial vacuum test. Next i added dye into the system (r12) and found NO leak during that time (blowing cold). A month later it went from cold to cool to nothing. NOW the dye method works, it all leaked out from the compressor.

I would go back to the SA and get something in writing that you may have a faulty compressor and that they should replace if any a leak is found within a given time/warranty.

[deathbunny]

Originally Posted by #Tee

I agree with BavarianFanatic, ive personally evac/charged ac systems before and used dye to detect a leak. My experience was NO leak found on the initial vacuum test. Next i added dye into the system (r12) and found NO leak during that time (blowing cold). A month later it went from cold to cool to nothing. NOW the dye method works, it all leaked out from the compressor.

I would go back to the SA and get something in writing that you may have a faulty compressor and that they should replace if any a leak is found within a given time/warranty.

+ 1
If you have documentation showing the problem was there before the warranty ran out you at least have a fighting chance of getting it covered later.

I just had the same problem with my 08. I took it to my indy shop that I trust and he said the compressors have problems often on these and he expected thats what was wrong. After checking it out he said he couldn't find any leaks at least big enough to detect so he just filled it up and it has been working fine so far but that was only about a month ago. I was about 3/4 of a pound light.

I think once you take a car in for a problem before you warranty expires, in most cases the documentation of this will be enough for BMW NA to cover it if you car slips out of warranty.

[chatoyer]

I'm going in soon for this exact issue. Will report back, but thanks to everyone above for their posts - useful info!

[shadow191]

Now that there's UV dye in the system and it's fully pressurized, the leak will probably be detected shortly. Typically leaks get bigger and the system will lose pressure faster. I recently went through all this, had a tiny hole in the condensor and couldn't find it even with dye at first. Then it went from loosing refrigerant in a month to about 2 hours as the leak got bigger.

Sometimes, there can be an issue with the schraeder valves themselves. But you are correct that the systems are entirely sealed so unless it's been like 20 years, you shouldn't lose refrigerant without there being a problem.

[bhmax16]

Definitely not a normal loss. I used to do automotive A/C work all the time (I was the only MACS certified guy in my shop prior to getting out of the business). I'm curious if they even performed the vacuum test correctly. Some technicians simply check to see if the vacuum achieves a particular level while sucking down the system, but if the rate in which the machine pulls a vacuum is greater than the rate in which the leak in the system causes a pressure loss then this method is useless. The proper way to perform the test is to place the vacuum on the system, then shut off the vacuum pump and let the system sit and visually watch the gauge to see if it's still holding the same vacuum level after, say, 15-20 minutes. If it is, then I'd let it sit even longer in your case. With the amount of loss you mentioned, it is anything but normal. It's not uncommon for vehicles that are 10+ years old to still be blowing cool air on their original factory charges. If test is still inconclusive, then I would go ahead and recharge and dye the system then tell the customer to come back in a week or so to check over with a UV light. If no leaks are detected visually, then go around the evaporator area with a sniffer (they make tools that can detect this stuff though it is odorless) which can easily aid in determining if the evap core is the source of the leak prior to ripping the dashboard apart. My 2 cents

[VeloTime]

Just to clarify. The dye test was performed after the system was recharged.

The exact steps listed were Vacuum Test and Leak Test performed, as well as noting that the system was recharged with dye added. So I'm assuming no nitrogen pressure test was done.

Question. Who is on the hook for CPO warranty work? Is that different than normal factory warranty work? I always assumed the dealer gets paid the shop rate for the job one way or the other. Do they have to eat the labor costs for warranty work?

[chatoyer]

Originally Posted by chatoyer

I'm going in soon for this exact issue. Will report back, but thanks to everyone above for their posts - useful info!

Just for the sake of documenting for others who may do a search, I had my AC fixed today - they replaced two shrater/shrator (however they are spelled) valves and replaced the refridgerant. Blows ice, ice cold air now.

[ken1137]

Originally Posted by chatoyer

Just for the sake of documenting for others who may do a search, I had my AC fixed today - they replaced two shrater/shrator (however they are spelled) valves and replaced the refridgerant. Blows ice, ice cold air now.

I assume you had the same symptoms? Just to get a bit of cold air I had to close the two middle vents and rear vents. Still not cold enough. Thanks for the information. I'll have the dealer check the A/C shrader valves.