Engine Surging/Hesitating between 1500

Rudy335xi · 06-15-2011, 10:52 AM

So I've started to notice something that has me concerned recently... If I'm driving along at a constant speed, not accelerating or decelerating, I notice a very slight surging and/or hesitation when the engine is between 1500 - 2000 rpms. It's very slight, but for a brand new 2011 335xi coupe with only 1800 miles, I wouldn't expect anything like this. I'm calling the dealer as it was just in to get a wastegate line repaired on the turbo, but I noticed before that issue. Anyone have any thoughts? No error messages which makes me wonder if the dealer will be looking for a needle in a stack of needles here.

youngb4 · 06-15-2011, 02:41 PM

Rudy - Have you recently started driving with the air conditioning on? I have the same ride as you and have noticed slight RPM fluctuations when the compressor is active (A/C on). Every car I've owned has slight RPM variations with A/C on though, makes sense with the added load of the refridgeration cycle, but I digress. Most of the fluctuations I've noticed have been at idle, I have not noticed anything while sustaining constant RPM between the 1500 and 2000 range, but also really haven't been looking for it. Also, is your engine warmed up to typical operating temperature when you notice this or does it occur after cold start? Just want to figure out your conditions so I can try and duplicate later on tonight!

06-15-2011, 10:52 AM	#1
Rudy335xi New Member 1 Rep 11 Posts Drives: 2011 335xi Coupe Join Date: Mar 2011 Location: Mid-Atlantic iTrader: (0)	Engine Surging/Hesitating between 1500 - 2000 rpms??? So I've started to notice something that has me concerned recently... If I'm driving along at a constant speed, not accelerating or decelerating, I notice a very slight surging and/or hesitation when the engine is between 1500 - 2000 rpms. It's very slight, but for a brand new 2011 335xi coupe with only 1800 miles, I wouldn't expect anything like this. I'm calling the dealer as it was just in to get a wastegate line repaired on the turbo, but I noticed before that issue. Anyone have any thoughts? No error messages which makes me wonder if the dealer will be looking for a needle in a stack of needles here.
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06-15-2011, 02:41 PM	#2
youngb4 Private 1 Rep 94 Posts Drives: 2011 E92 335i M Sport Join Date: Jan 2011 Location: Kansas iTrader: (0)	Rudy - Have you recently started driving with the air conditioning on? I have the same ride as you and have noticed slight RPM fluctuations when the compressor is active (A/C on). Every car I've owned has slight RPM variations with A/C on though, makes sense with the added load of the refridgeration cycle, but I digress. Most of the fluctuations I've noticed have been at idle, I have not noticed anything while sustaining constant RPM between the 1500 and 2000 range, but also really haven't been looking for it. Also, is your engine warmed up to typical operating temperature when you notice this or does it occur after cold start? Just want to figure out your conditions so I can try and duplicate later on tonight!
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