E70 X5M misfiring/sputtering

NYAWE60 · 11-24-2021, 05:34 PM

Hi guys,

So I drove my car just fine about a week ago came home and then when I went out a couple hours later the car started sputtering and went into low power mode.

The last time I did that it was because of bad coils and spark plugs but that was only 15 months ago and I replaced all of them. So I took it to one of New York's most advanced repair shops and they replace the coils and the plugs again but then it still did the same thing. Then they replaced the low pressure fuel pump which was a pretty invasive job but it did the same thing again.

Do you guys have any idea what it could possibly be at this point it's becoming really expensive? The engine is still throwing the same codes with misfiring and cylinder three and cylinder eight. The car has been well-maintained its entire life and has 90,000 miles on it right now.

Thanks in advance!

Bengineer330 · 11-24-2021, 05:51 PM

Fuel, Air, Spark. Sounds like they got the Fuel and Spark part replaced. Next would be to check Air. I would be looking for a vacuum leak, too much air can upset the fuel/air ratio causing a miss fire. Quick test is to idle the car, open the hood and lightly spray some WD40 near the coolant reservoir and the oil fill cap. Don’t go nuts but what your looking for is the idle to rise slightly. That would tell you that there is a vacuum leak on the CCV system

NYAWE60 · 11-24-2021, 06:33 PM

Quote:

Originally Posted by Bengineer330

Fuel, Air, Spark. Sounds like they got the Fuel and Spark part replaced. Next would be to check Air. I would be looking for a vacuum leak, too much air can upset the fuel/air ratio causing a miss fire. Quick test is to idle the car, open the hood and lightly spray some WD40 near the coolant reservoir and the oil fill cap. Don't go nuts but what your looking for is the idle to rise slightly. That would tell you that there is a vacuum leak on the CCV system

Thank you for the sound response. I hope we have some additional input. I'm a couple grand in the hole right now.

askjeeves · 11-25-2021, 10:13 AM

Do you know what fault codes the car has? Does the car seem to run fine during cold start? The engine vent pipes tend to crack, causing vacuum leaks.

https://www.xbimmers.com/forums/show....php?t=1413583

11-24-2021, 05:34 PM	#1
NYAWE60 Captain 650 Rep 779 Posts Drives: 2008 Porsche 911 Turbo 6 speed Join Date: Jan 2011 Location: NYC iTrader: (0)	Hi guys, So I drove my car just fine about a week ago came home and then when I went out a couple hours later the car started sputtering and went into low power mode. The last time I did that it was because of bad coils and spark plugs but that was only 15 months ago and I replaced all of them. So I took it to one of New York's most advanced repair shops and they replace the coils and the plugs again but then it still did the same thing. Then they replaced the low pressure fuel pump which was a pretty invasive job but it did the same thing again. Do you guys have any idea what it could possibly be at this point it's becoming really expensive? The engine is still throwing the same codes with misfiring and cylinder three and cylinder eight. The car has been well-maintained its entire life and has 90,000 miles on it right now. Thanks in advance! __________________ 2008 997TT 6-Speed - stock (for now, just enjoying) 2019 Audi S5 Sportback JB4 equipped - mommy mobile 2011 X5M - daily family hauler 2010 Toyota Prius - stealth mobile 140K miles since new and still 45 MPG 2017 Lexus GX460 - (gone) - easily one of the most reliable cars I?ve ever owned 2014 328i xDrive M-Sport - 270 WHP w/JB4 (gone) 2010 BMW 535i RWD - 400 WHP (gone) 1992 R32 Nissan Skyline GTR 500 WHP (gone) 1993 Toyota Supra TT 6 speed - 500 WHP (gone)
	Appreciate 0 Tweet Quote

11-24-2021, 05:51 PM	#2
Bengineer330 Private First Class 46 Rep 101 Posts Drives: Le Mans Blue 2011 E92 M3 Join Date: Oct 2014 Location: Genesee, WI iTrader: (1)	Fuel, Air, Spark. Sounds like they got the Fuel and Spark part replaced. Next would be to check Air. I would be looking for a vacuum leak, too much air can upset the fuel/air ratio causing a miss fire. Quick test is to idle the car, open the hood and lightly spray some WD40 near the coolant reservoir and the oil fill cap. Don’t go nuts but what your looking for is the idle to rise slightly. That would tell you that there is a vacuum leak on the CCV system Last edited by Bengineer330; 11-24-2021 at 05:59 PM..
	Appreciate 0 Quote

11-25-2021, 10:13 AM	#4
askjeeves Captain 147 Rep 957 Posts Drives: e92 m3/spece30 Join Date: Jun 2008 Location: Miami, FL iTrader: (1)	Do you know what fault codes the car has? Does the car seem to run fine during cold start? The engine vent pipes tend to crack, causing vacuum leaks. https://www.xbimmers.com/forums/show....php?t=1413583 __________________ 2011 e92 ///m3 zcp - jzb/fr ED 6/29/10
	Appreciate 0 Quote