A/C no longer cold!

[eocrm3]

I have a 2010 m3 coupe, and noticed my A/C blowing out cool air, not cold as before, about two weeks ago. Last I week I scheduled a service apt for tomorrow (Sep 25) as I am less than 500 miles away from my warranty expiring.

Up to about three days ago the a/c would still blow out cool air, enough to keep the cabin somewhat comfortbale in the 95 degree south Texas heat, but then 2 days ago I noticed the drivers side vents blow only warm air out, while the passenger side still blew out cool air.

And now this morning both drivers side and passenger side vents are all blowing nothing but warm air. This is with a/c set to 60 on both sides, re-circulated air. I also notice a distinct plastic smell (not a burning smell though) with the a/c on, blowing out warm air.

From reading up on the forum it seems like most people have the evaporator replaced when the a/c gives out. From what my m3 is doing does it seem to be an evaporator issue?

I just want to make sure that whatever the dealer replaces/repairs is in fact the issue as it'll probably be the last repair I'll have under warranty. I hope they just don't try to add refrigerant or attempt a short-term fix to have the issue re-appear in the near future.

I appreciate any advice on what to expect from the dealer on this repair. Thanks guys!

[Lorde]

No, it sounds like you are just low on refrigerant. Same thing happened to me with no leaks on an 08 m3.

[///M Power-Belgium]

Originally Posted by eocrm3

I have a 2010 m3 coupe, and noticed my A/C blowing out cool air, not cold as before, about two weeks ago. Last I week I scheduled a service apt for tomorrow (Sep 25) as I am less than 500 miles away from my warranty expiring.

Up to about three days ago the a/c would still blow out cool air, enough to keep the cabin somewhat comfortbale in the 95 degree south Texas heat, but then 2 days ago I noticed the drivers side vents blow only warm air out, while the passenger side still blew out cool air.

And now this morning both drivers side and passenger side vents are all blowing nothing but warm air. This is with a/c set to 60 on both sides, re-circulated air. I also notice a distinct plastic smell (not a burning smell though) with the a/c on, blowing out warm air.

From reading up on the forum it seems like most people have the evaporator replaced when the a/c gives out. From what my m3 is doing does it seem to be an evaporator issue?

I just want to make sure that whatever the dealer replaces/repairs is in fact the issue as it'll probably be the last repair I'll have under warranty. I hope they just don't try to add refrigerant or attempt a short-term fix to have the issue re-appear in the near future.

I appreciate any advice on what to expect from the dealer on this repair. Thanks guys!

I see you live in Texas with almost all the time hot weather ,so you use the airco everyday !
What i want to say is that my wive had a Subaru Legacy and after six years she had the same problem as you ,so i took the car to Midas and i asked for a Freon gas change ....problem solved,and cold air like from day one...for 20 Euro's...so maybe it could be this

[FogCityM3]

Make sure they test it using the cooling sensor devices that go in front of the vents and also try the A/C out right away once you get the car back if they claim it was due to something other than the evaporator. The dealer tried to do the same thing with me, saying it was a bad sensor, which was replaced, so they claimed "problem fixed". But as I drove the "fixed" car, I could tell it wasn't cooling down, so took it back and lo and behold, they had to replace the evaporator. Just don't let them take any short cuts.

[eocrm3]

When I spoke to the service advisor over the phone to tell him about the issue and set up the apt he told me right away that it was most likely the evaporator needing to be replaced. I will be driving 2 hours to the dealership tomorrow morning, so he set me up for a loaner as he menionted it's at least a 2-3 day job.

*Another thing I forgot to mention is that over the past several weeks there was a type of hissing that was audible from behind the dash as soon as I turned on the a/c, which I never noticed before.

After the a/c starting blowing nothing but warm air the a/c remains hissing the whole time I have it on......not sure what this hissing is or what it may indicate, but it is only audible when I now turn on the a/c....any ideas what it could be?

Thanks again guys!

[MilehighM3]

The hissing sound is due to a low refrigerant charge. As far as the advisor diagnosing the car over the phone, that's very unprofessional. It doesn't matter if 100% of the cars have the same issue with the same cause, that still should never be done. Now what if it's a leaking service port or something else? You'll expect the evaporator without a doubt.
I'm sure they will get it fixed and cooling properly, but an evap is not a 2-3 day job. Even the first time around for any given tech. If it can't be done in less than a day, they're techs need some evaluating. It's a 8.3 hour job under warranty and any given tech can do it in half that, especially in Texas where evap replacements are done fairly regularly on 1,3, X5 and Z4s.

[davesaddiction]

Had my evaporator replaced as well, thankfully under factory warranty.

[BCA]

I've had this issue on two E90s including my 2009 E90 M. They may try to recharge the refrigerant first, and that will likely work temporarily (it did on both of mine). But I eventually needed evaporator replacements and I bet you will too, so you should push for that if your warranty is about to expire.

[SoTempted]

I'm having the same issue... I hope I just need a recharge. Moving to middle of nowhere New Mexico where the closest dealer is 100 miles away.

[OilPatch]

Originally Posted by SoTempted

I'm having the same issue... I hope I just need a recharge. Moving to middle of nowhere New Mexico where the closest dealer is 100 miles away.

Is it BMW of the Permian basin?

[davesaddiction]

Aren't these systems supposed to be "lossless"?

As in, there's should be no need to add extra refrigerant unless some is escaping somehow?

[C-M2]

Take it to the dealer, car should still be under warranty unless you have over 50k. My dealer found leaking o-rings at the expansion valve. Both replaced and recharged. No issues since

[eocrm3]

Just got m3 back and evaporator was replaced. A/C is now back to ice cold as before. Hopefully this evaporator will last a while as I am now less than 100 miles away from warranty expiring!