Car is Vascillating on Cold Starts for a Minute

Longboarder · 01-23-2012, 06:36 PM

When starting the car cold, something is causing the car to shake rather dramatically for about a minute until it warms up. After about a minute, the shaking begins to subside and 10 seconds later the shaking is completely gone. Anyone experience something like this? Thanks.

Beemw335 · 01-23-2012, 07:03 PM

N54 has always been rough on cold starts.
But let us know mileage, and info on plugs and injectors.

Longboarder · 01-23-2012, 07:08 PM

Quote:

Originally Posted by Beemw335

N54 has always been rough on cold starts.
But let us know mileage, and info on plugs and injectors.

Good question. The car is a 2010 with 25,000 miles...original plugs/coils/injectors. I bought it new. Never one problem with the car. Runs fantastic otherwise.

Definitely not the typical N54 rough cold start idle. If you get out of the car, you can see it shaking back and forth. But it doesn't throw any codes.

I have a service due in about 1,500 miles so I was just going to have BMW look at it then....unless there could be a more serious issue causing the vascillation in which case I would bring it in asap.

nitehawk · 01-23-2012, 07:34 PM

I feel it slightly on cold starts as well and it subsides as the oil/coolant temps rise. Never thought much of it as the car has 37k miles on it without encountering any related issues.

Syndicategt · 01-23-2012, 07:38 PM

Is the RPM bouncing too? Could be injector/coil pack issues.

Longboarder · 01-24-2012, 11:52 AM

Quote:

Originally Posted by Syndicategt

Is the RPM bouncing too? Could be injector/coil pack issues.

No, RPMs are steady at a bit over 1,000 and then as the car warms the idle drops to ~ 800 or so. From the time I start the car, it takes only a few seconds for the vascillation to start and then it continues for a short time and then subsides completely once the idle drops to 800. Weird.

Do these cars have a harmonic balancer?

JamesM3M5 · 01-24-2012, 12:13 PM

Yes, pretty much all engines do now - at least all performance engines.

I'd try plugs, first. Most poor cold start issues I've seen on non turbo engines are from plugs. I know you only have 25k miles, but that's where I'd start.

boostaholic786 · 01-24-2012, 01:07 PM

I honestly think its probably the plugs and injectors. If its shaking to where you can see your car move back and forth then there is definently a problem in those areas. I would take it in as soon as you can and let the dealership know what the car is doing. Since your in warranty you dont have anything to worry about. Even out of warranty theres recalls on HPFP LPFP fuel lines and if im not mistaken injectors till 125,000 miles. (I have no idea where they got that number).

01-23-2012, 06:36 PM	#1
Longboarder Major General 3431 Rep 6,771 Posts Drives: 2016 BMW i8 Join Date: Dec 2006 Location: Monarch Beach iTrader: (1) Garage List 2012 BMW e92 M3 [0.00] 2021 BMW X5M [10.00] 2015 Porsche 991 Tu ... [10.00] 2015 Porsche 991 GT3 [10.00]	Car is Vascillating on Cold Starts for a Minute When starting the car cold, something is causing the car to shake rather dramatically for about a minute until it warms up. After about a minute, the shaking begins to subside and 10 seconds later the shaking is completely gone. Anyone experience something like this? Thanks. __________________ Current BMWs: 2022 X5 40i, 2016 X5 50i 2015 Porsche 991 Turbo S 1979 Porsche 911 Turbo (930) a couple others IG: longboarder949; YouTube: https://www.youtube.com/channel/UCT1...eoFBszPIK0gf9w
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01-23-2012, 07:03 PM	#2
Beemw335 Colonel 62 Rep 2,013 Posts Drives: 335i Join Date: Mar 2011 Location: My car is my home iTrader: (2)	N54 has always been rough on cold starts. But let us know mileage, and info on plugs and injectors.
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01-23-2012, 07:34 PM	#4
nitehawk Lieutenant Colonel 102 Rep 1,903 Posts Drives: e92 335i 6MT Join Date: May 2011 Location: Toronto iTrader: (15) Garage List E92 BMW 335i [9.00] E92 BMW 335i \| Retired [10.00]	I feel it slightly on cold starts as well and it subsides as the oil/coolant temps rise. Never thought much of it as the car has 37k miles on it without encountering any related issues.
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01-23-2012, 07:38 PM	#5
Syndicategt Brigadier General 153 Rep 3,730 Posts Drives: 335i Join Date: Sep 2009 Location: Nor Cal iTrader: (11)	Is the RPM bouncing too? Could be injector/coil pack issues. __________________ 2008 BMW 335i e90 - Sold - Rob Beck Turbos / PROcede V5 / Aquamist HFS-4 / AR Downpipes / AE Exhaust / ER Comp FMIC / ER CP / TiAL BOV / Custom Intake / RPI Scoops / Quaife LSD / Swift-Koni Coilovers / DSS HS / Morr VS8.2 Sig Black / Michelin PSS / P3 Boost Guage / M3 body / M3 steering wheel / Adam's Rotors / Hawk HPS / SS lines /
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01-24-2012, 12:13 PM	#7
JamesM3M5 Some dude 92 Rep 1,780 Posts Drives: E92 335i Join Date: Sep 2011 Location: Northern VA iTrader: (0)	Yes, pretty much all engines do now - at least all performance engines. I'd try plugs, first. Most poor cold start issues I've seen on non turbo engines are from plugs. I know you only have 25k miles, but that's where I'd start. __________________ RRT E92 335i/6MT with stuff and things
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01-24-2012, 01:07 PM	#8
boostaholic786 Captain 40 Rep 623 Posts Drives: E92 N54 with MHD Custom flash Join Date: Dec 2011 Location: Plano TX iTrader: (0)	I honestly think its probably the plugs and injectors. If its shaking to where you can see your car move back and forth then there is definently a problem in those areas. I would take it in as soon as you can and let the dealership know what the car is doing. Since your in warranty you dont have anything to worry about. Even out of warranty theres recalls on HPFP LPFP fuel lines and if im not mistaken injectors till 125,000 miles. (I have no idea where they got that number).
	Appreciate 0 Quote