Surging/Vibration with AC on

Bfrancom2 · 09-06-2020, 01:40 AM

Rough Idle on B58 with A/C on

I drive a 2017 BMW M240i with the B58. I‘m under warranty but have an odd issue the dealership claims they can’t find or fix and I’m looking for some insight.

The car runs fantastic, except for in warm weather with the A/C engaged. The idle is lumpy and it surges/vibrates unevenly in the cabin. The violent surging every 1-2 seconds is only super bad when it’s 100+ degrees outside and I’ve been driving the car for 15-20 min, and it’s slightly heat soaked. While some vibration is normal in any vehicle with load caused by the compressor, it is an uneven and unpredictable surging pattern. The RPMs never fluctuate, just surging felt in the cabin.

I’ve checked - AFRs, Fuel Pressure, etc all seem fine. As I stated it only happens once the car had heat soaked a bit in warm weather, maybe 10-15 minutes after starting the car.

Any idea what would be causing this? Dealer replaced the Idle control valve but that’s it. A/C system, belts, etc all inspected by bmw dealer and have no issues.

Thanks.

Murf · 09-06-2020, 08:57 AM

There are multiple posts about this - my '16 M235i does it as well. Consensus is that it's normal.

Ron Jeffries · 09-06-2020, 11:18 AM

normal = common, probably harmless, anyway we can't fix it.

XutvJet · 09-06-2020, 01:38 PM

"Violent surging"? It's hard to envision this without rpms shooting up. That's not the case, right?

DaleHeinz · 09-06-2020, 02:28 PM

My 17 M240 had the same issue, at idle. Ended up being a warranty issue twice and they had to work with techs in Germany to remedy the issue.

Are you losing A/C cooling abilities? Mine did. Air was only slightly chilled and then went straight room temp.

Bfrancom2 · 09-06-2020, 02:58 PM

Quote:

Originally Posted by XutvJet

"Violent surging"? It's hard to envision this without rpms shooting up. That's not the case, right?

Violent may be an exaggeration, but it’s severe enough to feel like the car is bouncing up and down 200+ RPM. Can be felt over even bass heavy music at 75% volume.

Bfrancom2 · 09-06-2020, 02:59 PM

Quote:

Originally Posted by DaleHeinz

My 17 M240 had the same issue, at idle. Ended up being a warranty issue twice and they had to work with techs in Germany to remedy the issue.

Are you losing A/C cooling abilities? Mine did. Air was only slightly chilled and then went straight room temp.

Was it only when it was really warm outside? Like 100+?

No cooling loss. Just runs rough with it on while it’s hot out and the car’s intake temps exceed 145-150f. That’s when I notice it start to occur.

Bfrancom2 · 09-06-2020, 03:00 PM

Quote:

Originally Posted by Murf

There are multiple posts about this - my '16 M235i does it as well. Consensus is that it's normal.

Link possibly? Been searching around and haven’t found many similar situations.

DaleHeinz · 09-06-2020, 03:17 PM

Quote:

Originally Posted by Bfrancom2

Quote:

Originally Posted by DaleHeinz

My 17 M240 had the same issue, at idle. Ended up being a warranty issue twice and they had to work with techs in Germany to remedy the issue.

Are you losing A/C cooling abilities? Mine did. Air was only slightly chilled and then went straight room temp.

Was it only when it was really warm outside? Like 100+?

No cooling loss. Just runs rough with it on while it’s hot out and the car’s intake temps exceed 145-150f. That’s when I notice it start to occur.

It was 3 years ago when the car was new, so my memory is foggy, but it was around summer time. Ended up being a mix of compressor and evaporator issues. If you'd like, Call BMW of Annapolis, MD and see if they'll give you the service info on the fix. Maybe that would help your dealer address your issue. PM me if you want specifics.

delvec03 · 09-06-2020, 03:31 PM

I had an issue lime this in my n20, so it could be different. issue was caused by refrigerant pressure being too high. sounds like what might be happening based on only occurring in hight temps.

Bfrancom2 · 09-07-2020, 07:45 PM

Quote:

Originally Posted by delvec03

I had an issue lime this in my n20, so it could be different. issue was caused by refrigerant pressure being too high. sounds like what might be happening based on only occurring in hight temps.

How would this be fixed if it was the issue?

Bfrancom2 · 09-07-2020, 07:48 PM

Quote:

Originally Posted by DaleHeinz

It was 3 years ago when the car was new, so my memory is foggy, but it was around summer time. Ended up being a mix of compressor and evaporator issues. If you'd like, Call BMW of Annapolis, MD and see if they'll give you the service info on the fix. Maybe that would help your dealer address your issue. PM me if you want specifics.

I'll do that - also, my powertrain warranty is voided due to tuning. And no, the tune didn't cause this issue, it's been here since I bought the car.

Do you think the aspect of them looking at my compressor/evap would be affected by this void? Obviously if I blow a turbo it's not covered, but what about the A/C system specifically?

delvec03 · 09-07-2020, 08:55 PM

Quote:

Originally Posted by Bfrancom2

Quote:

Originally Posted by delvec03

I had an issue lime this in my n20, so it could be different. issue was caused by refrigerant pressure being too high. sounds like what might be happening based on only occurring in hight temps.

How would this be fixed if it was the issue?

I had the refrigerant depressurized until the issue resolved. I had the AC on as it was done, also as it was surging, ref was bled off and the surging became less frequent and eventually.stopped.

DaleHeinz · 09-16-2020, 07:54 PM

Quote:

Originally Posted by Bfrancom2

Quote:

Originally Posted by DaleHeinz

It was 3 years ago when the car was new, so my memory is foggy, but it was around summer time. Ended up being a mix of compressor and evaporator issues. If you'd like, Call BMW of Annapolis, MD and see if they'll give you the service info on the fix. Maybe that would help your dealer address your issue. PM me if you want specifics.

I'll do that - also, my powertrain warranty is voided due to tuning. And no, the tune didn't cause this issue, it's been here since I bought the car.

Do you think the aspect of them looking at my compressor/evap would be affected by this void? Obviously if I blow a turbo it's not covered, but what about the A/C system specifically?

Tune shouldn't effect that. Climate control is separate from that.

09-06-2020, 01:40 AM	#1
Bfrancom2 New Member 4 Rep 26 Posts Drives: M240i Join Date: Aug 2020 Location: Tempe AZ iTrader: (0)	Surging/Vibration with AC on Rough Idle on B58 with A/C on I drive a 2017 BMW M240i with the B58. I‘m under warranty but have an odd issue the dealership claims they can’t find or fix and I’m looking for some insight. The car runs fantastic, except for in warm weather with the A/C engaged. The idle is lumpy and it surges/vibrates unevenly in the cabin. The violent surging every 1-2 seconds is only super bad when it’s 100+ degrees outside and I’ve been driving the car for 15-20 min, and it’s slightly heat soaked. While some vibration is normal in any vehicle with load caused by the compressor, it is an uneven and unpredictable surging pattern. The RPMs never fluctuate, just surging felt in the cabin. I’ve checked - AFRs, Fuel Pressure, etc all seem fine. As I stated it only happens once the car had heat soaked a bit in warm weather, maybe 10-15 minutes after starting the car. Any idea what would be causing this? Dealer replaced the Idle control valve but that’s it. A/C system, belts, etc all inspected by bmw dealer and have no issues. Thanks.
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09-06-2020, 08:57 AM	#2
Murf Captain 885 Rep 896 Posts Drives: 2021 G80 M3C - Dravit Grey Join Date: Apr 2011 Location: Florida iTrader: (2)	There are multiple posts about this - my '16 M235i does it as well. Consensus is that it's normal.
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09-06-2020, 11:18 AM	#3
Ron Jeffries Old Member. Old in general, actually. 388 Rep 889 Posts Drives: 2018 M240i xDrive convertible Join Date: Feb 2013 Location: Michigan iTrader: (0)	normal = common, probably harmless, anyway we can't fix it.
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09-06-2020, 01:38 PM	#4
XutvJet Major General 5551 Rep 5,369 Posts Drives: 2011 Cayman Base, 2016 M235 Join Date: Mar 2016 Location: Kansas City iTrader: (-1)	"Violent surging"? It's hard to envision this without rpms shooting up. That's not the case, right? __________________ The forest was shrinking, but the Trees kept voting for the Axe, for the Axe was clever and convinced the Trees that because his handle was made of wood, he was one of them.
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09-06-2020, 02:28 PM	#5
DaleHeinz First Lieutenant 221 Rep 314 Posts Drives: M240Xi Estoril Blue Join Date: Apr 2017 Location: Washington DC area iTrader: (1)	My 17 M240 had the same issue, at idle. Ended up being a warranty issue twice and they had to work with techs in Germany to remedy the issue. Are you losing A/C cooling abilities? Mine did. Air was only slightly chilled and then went straight room temp.
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09-06-2020, 03:31 PM	#10
delvec03 First Lieutenant 90 Rep 351 Posts Drives: 228i Sport/ DSB Join Date: Feb 2015 Location: United States, DC iTrader: (0)	I had an issue lime this in my n20, so it could be different. issue was caused by refrigerant pressure being too high. sounds like what might be happening based on only occurring in hight temps.
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