Idle Surge When A/C Is On....

colt9987 · 04-22-2014, 10:35 PM

So someone reversed into me about a month ago and I finally just got my car back. The dealer body shop basically just replaced all of the thing in front of the engine (including the A/C), but there was no engine or frame damage.

I just used the A/C for the first time since getting the car back today and whenever I have the A/C on and come to a stop I get a hard idle surge. It is like the car is about to die and then the revs jump up pretty hard and surge the car forward and then the idle settles. The weird thing is that when the A/C is off, the car drives perfect!

I have had this problem twice before. The first time it was diagnosed as a software issue which seemed to fix it. The second time it was diagnosed as a fuel pump dying which seemed to fix it as well. But both of those times that I had the issue it did not matter if I had the A/C on or not though.

Does anyone know of anything I could check to fix the issue so I dont have to take off my mods again to take it to the dealer? Any help would be greatly appreciated. Thanks!

ItsHectic · 04-23-2014, 06:16 AM

Do you have extended warranty?

BLU135i · 04-23-2014, 06:47 AM

I'm gonna guess that you have a DCT.

Read this:
http://www.1addicts.com/forums/showt...&highlight=DCT

I have the same issue and am going to ask for the software fix when I take it in for an oil change next month.

cheshirecat79 · 04-23-2014, 09:03 AM

IMO, this wouldn't be a DCT issue as much as some kind of vacuum problem (possibly) when they did the repairs. This is not normal and it needs to be addressed.

colt9987 · 04-23-2014, 11:23 AM

It's just weird that the problem only occurs when the A/C is on.

I have already had the software updated the last time I had a similar issue which fixed the problem. The difference that time was that the issue occurred all the time, not just when the A/C is on.

It almost seems like the A/C is drawing too much power or something causing the car to almost die and surge whenever I come to a stop.

I am under warranty so if it comes down to it I can just remove my mods and take it in. I was just wondering if anyone knew of a simple fix or some things I might be able to check on my own to fix this issue without having to find the time to take my mods off.

04-22-2014, 10:35 PM	#1
colt9987 Lieutenant 45 Rep 437 Posts Drives: 135i Join Date: Sep 2009 Location: dallas iTrader: (2)	Idle Surge When A/C Is On.... So someone reversed into me about a month ago and I finally just got my car back. The dealer body shop basically just replaced all of the thing in front of the engine (including the A/C), but there was no engine or frame damage. I just used the A/C for the first time since getting the car back today and whenever I have the A/C on and come to a stop I get a hard idle surge. It is like the car is about to die and then the revs jump up pretty hard and surge the car forward and then the idle settles. The weird thing is that when the A/C is off, the car drives perfect! I have had this problem twice before. The first time it was diagnosed as a software issue which seemed to fix it. The second time it was diagnosed as a fuel pump dying which seemed to fix it as well. But both of those times that I had the issue it did not matter if I had the A/C on or not though. Does anyone know of anything I could check to fix the issue so I dont have to take off my mods again to take it to the dealer? Any help would be greatly appreciated. Thanks! __________________ 2011 135i
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04-23-2014, 06:16 AM	#2
ItsHectic But your honour it's my Affluenza I swear! 58 Rep 533 Posts Drives: at a reasonable speed Join Date: Aug 2011 Location: NSW iTrader: (0)	Do you have extended warranty? __________________ 135i M Sport DCT. BSM/Oyster/GP trim. FBO Cobb, Bilstein EDC coilovers, M3 bushings, PSS. Knowledge of the Tapa Tapa Tapa street race start.
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04-23-2014, 06:47 AM	#3
BLU135i Senior Chief Petty Officer USN 106 Rep 501 Posts Drives: X5 35d Join Date: Jan 2010 Location: Haze Grey iTrader: (1)	I'm gonna guess that you have a DCT. Read this: http://www.1addicts.com/forums/showt...&highlight=DCT I have the same issue and am going to ask for the software fix when I take it in for an oil change next month.
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04-23-2014, 09:03 AM	#4
cheshirecat79 Captain 32 Rep 919 Posts Drives: 370z & 135i Join Date: Dec 2012 Location: Port Saint Lucie, FL iTrader: (0)	IMO, this wouldn't be a DCT issue as much as some kind of vacuum problem (possibly) when they did the repairs. This is not normal and it needs to be addressed.
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04-23-2014, 11:23 AM	#5
colt9987 Lieutenant 45 Rep 437 Posts Drives: 135i Join Date: Sep 2009 Location: dallas iTrader: (2)	It's just weird that the problem only occurs when the A/C is on. I have already had the software updated the last time I had a similar issue which fixed the problem. The difference that time was that the issue occurred all the time, not just when the A/C is on. It almost seems like the A/C is drawing too much power or something causing the car to almost die and surge whenever I come to a stop. I am under warranty so if it comes down to it I can just remove my mods and take it in. I was just wondering if anyone knew of a simple fix or some things I might be able to check on my own to fix this issue without having to find the time to take my mods off. __________________ 2011 135i
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