2008 328i Coupe Rough Idle

rkennedy · 11-12-2017, 05:01 AM

I have a 2008 328i coupe with 87xxx miles on.
Recently my engine has been having a rough start and stumbling idle.
It’s definitely worse on a cold engine and haven’t really noticed it once the oil temp gets to normal operating temp.I try to warm up the engine as much as possible before driving it but unfortunately I mostly drive 2-3 miles to and from work daily in stop and go traffic. It will stumble when I come to a stop, doesn’t go below 500rpms but still stumbles.
I recently did an oil change with Mobil “European” 0W-40(have been for the past two years and always changed before 3000 miles since the last one.) I always clean my air intake when I change my oil, K&N filter.
Changed spark plugs at the same time with NGK Iridium.
I do have a Oil Pan Gasket leak, but don’t see how it would be related, I check my oil level regularly.
My bimmer is a SULEV, if you’re unaware, anything emissions related gets fixed by the dealership for free in California by law. Which I have taken advantage of in the past. That being said, before I take it in I want to make sure I don’t have to pay for the diagnostic if it isn’t emissions related, which I don’t believe it is.
One more note, before I made this post, I plugged my OBD II in on a cold start and didn’t get any codes.

gunnerxq · 11-14-2017, 06:41 PM

Maybe this?
http://www.pelicanparts.com/BMW/tech..._Replacing.htm

N54_e90 · 11-15-2017, 10:19 AM

^^

You can try cleaning them first. Takes 5 mins.

3002 tii · 11-20-2017, 11:11 PM

Changed plugs but what about ignition coils?

rkennedy · 11-21-2017, 08:17 AM

Haven’t changed the coils. Cleaned both intake and outtake solenoids. Helped a little but I have felt a few hiccups still. It’s a little better but I don’t think it fixed the enitire problem.

tom.gnade · 11-21-2017, 03:46 PM

I recently had a very similar problem, turned out to be ignition coil on cylinder 5. I had the shop do it since it was already there but it looks like they can be done pretty easily. They said the Coils fail frequently. It looks like there is an updated version, I think all 6 coils were on sale for maybe 160 at FCP. I may just change them all out at next oil change with new plugs.

Steadyhand · 11-30-2017, 06:41 PM

Could also be your fuel injectors. Does your car smell of gasoline when first started after sitting for 7+ hours (particularly when it's cold outside)?

If so, that could explain rough starts and it getting better after coming to normal operating temp, because the inside seals in your injectors could be worn, thus letting small amounts of fuel to leak through after sitting (post fuel rail, of course).

This was happening for my 328 and 330 (both e90) and the solution was installing refurbished fuel injectors (w/new seals, cleaned, new o-rings, etc.). Cost was extremely reasonable and the DIY was maybe a 4 out of 10 (1 1/2 hours in my driveway).

11-12-2017, 05:01 AM	#1
rkennedy Registered 0 Rep 2 Posts Drives: 2008 328i Coupe Join Date: Oct 2016 Location: San Diego iTrader: (0) Garage List 2008 BMW 328i Coupe [0.00]	2008 328i Coupe Rough Idle I have a 2008 328i coupe with 87xxx miles on. Recently my engine has been having a rough start and stumbling idle. It’s definitely worse on a cold engine and haven’t really noticed it once the oil temp gets to normal operating temp.I try to warm up the engine as much as possible before driving it but unfortunately I mostly drive 2-3 miles to and from work daily in stop and go traffic. It will stumble when I come to a stop, doesn’t go below 500rpms but still stumbles. I recently did an oil change with Mobil “European” 0W-40(have been for the past two years and always changed before 3000 miles since the last one.) I always clean my air intake when I change my oil, K&N filter. Changed spark plugs at the same time with NGK Iridium. I do have a Oil Pan Gasket leak, but don’t see how it would be related, I check my oil level regularly. My bimmer is a SULEV, if you’re unaware, anything emissions related gets fixed by the dealership for free in California by law. Which I have taken advantage of in the past. That being said, before I take it in I want to make sure I don’t have to pay for the diagnostic if it isn’t emissions related, which I don’t believe it is. One more note, before I made this post, I plugged my OBD II in on a cold start and didn’t get any codes.
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11-14-2017, 06:41 PM	#2
gunnerxq Lieutenant Colonel 213 Rep 1,782 Posts Drives: e90 "325i" Join Date: Sep 2010 Location: New York iTrader: (1)	Maybe this? http://www.pelicanparts.com/BMW/tech..._Replacing.htm
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11-15-2017, 10:19 AM	#3
N54_e90 Don 46 Rep 299 Posts Drives: '09 E90 335xi Family Sedan Join Date: Jan 2017 Location: Your Mother's House iTrader: (0)	^^ You can try cleaning them first. Takes 5 mins.
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11-20-2017, 11:11 PM	#4
3002 tii Lieutenant General 2286 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.24]	Changed plugs but what about ignition coils? __________________ Follow for latest mods
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11-21-2017, 08:17 AM	#5
rkennedy Registered 0 Rep 2 Posts Drives: 2008 328i Coupe Join Date: Oct 2016 Location: San Diego iTrader: (0) Garage List 2008 BMW 328i Coupe [0.00]	Haven’t changed the coils. Cleaned both intake and outtake solenoids. Helped a little but I have felt a few hiccups still. It’s a little better but I don’t think it fixed the enitire problem.
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11-21-2017, 03:46 PM	#6
tom.gnade Apex Forged 19", AA headers, MILVs, 3IM, Euro Intake, Swift Spec-R 87 Rep 255 Posts Drives: 2013 328i coupe Join Date: May 2016 Location: Forest Hill, MD iTrader: (1) Garage List 2013 BMW 328i [0.00]	I recently had a very similar problem, turned out to be ignition coil on cylinder 5. I had the shop do it since it was already there but it looks like they can be done pretty easily. They said the Coils fail frequently. It looks like there is an updated version, I think all 6 coils were on sale for maybe 160 at FCP. I may just change them all out at next oil change with new plugs.
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11-30-2017, 06:41 PM	#7
Steadyhand Private First Class 52 Rep 100 Posts Drives: E90, E70, F30, F97/G01 X3M Join Date: Feb 2012 Location: Virginia iTrader: (0)	Could also be your fuel injectors. Does your car smell of gasoline when first started after sitting for 7+ hours (particularly when it's cold outside)? If so, that could explain rough starts and it getting better after coming to normal operating temp, because the inside seals in your injectors could be worn, thus letting small amounts of fuel to leak through after sitting (post fuel rail, of course). This was happening for my 328 and 330 (both e90) and the solution was installing refurbished fuel injectors (w/new seals, cleaned, new o-rings, etc.). Cost was extremely reasonable and the DIY was maybe a 4 out of 10 (1 1/2 hours in my driveway).
	Appreciate 0 Quote