Rough idle and intake valve carbon build-up. How is this possible?

Jeff@TopGearSolutions · 08-22-2011, 06:55 PM

It helps to run it all out on the highway, especially a car that is driven like a grandma, but inevitably their will still be carbon build up.

Syndicategt · 08-22-2011, 07:44 PM

Take you IC pipe off to see another way gunk gets in there

JO3 · 08-22-2011, 08:07 PM

My car is in the shop right now to get the valves cleaned. I took pics of the valves, and they were pretty nasty. I'll post them up later.

Also, for the OP, check out this thread if you want a TON of information about our crankcase ventilation system. http://www.e90post.com/forums/showthread.php?t=518306

JO3 · 08-22-2011, 08:10 PM

Quote:

Originally Posted by secretsquirrel

As Tibra said, no. Nasty valves is not a defect. Its just a bad characteristic of DI engines in general (at least high performance Euro engines). Other manufacturers are beginning to use DI engines (toyota/lexus and ford). I'm pretty sure there owners wont be as understanding about sludge issues as luxury Euro owners, so I would expect them to have a solution pretty quickly.

The lexus DI engines (at least the 3.5l) uses both port and direct injection. I always wondered why it needed it, but now I see that the lexus engineers can actually see into the future, lol.

Also, I'm thinking that another benefit of dual injection is that for big turbo applications, it would be easier to beef up the fuel system, but that's for another thread.

itsbrokeagain · 08-22-2011, 08:16 PM

I have done 4 of these as of latley...anything north of 50k i highly recommend doing it. LostMarines were super gunked up and he uses a lot of meth...we gained 12hp alone just from the cleaning on the dyno

mave198 · 08-22-2011, 08:19 PM

Hey Matt...can u pm me a quote for cleaning out those valves???

tibra1 · 08-22-2011, 08:59 PM

Quote:

Originally Posted by Ozzie Goat

OR
Reading stumbling/jerky acceleration threads, pottypants (I think) suggested an olde school solution to this new age DI problem.
Took my car out on the open highway. 80mph 4th gear 30 minutes at about 4k.
Never visually inspected carbon on my valves, but the stumbling is gone.
It's free, try it.

Yes I have heard that works as it "blows" out some of the carbon deposits but its only a band aid..a proper manual clean will def have better results

Ozzie Goat · 08-22-2011, 09:15 PM

YOU calling ME a Grandma?

Quote:

Originally Posted by Jeff@topgearsolutions

It helps to run it all out on the highway, especially a car that is driven like a grandma, but inevitably their will still be carbon build up.

drfrink24 · 08-22-2011, 10:07 PM

My rough idle was fixed by running two back to back fuel system treatments by the dealer, under warrenty.

raceyBMW · 08-22-2011, 10:37 PM

Quote:

Originally Posted by tibra1

Yes I have heard that works as it "blows" out some of the carbon deposits but its only a band aid..a proper manual clean will def have better results

AKA Italian Tune-up.

If your rough idle is caused by clogged or dirty injector tips, then a proper fuel injector cleaner should do the trick...but if its from valve stem build-up, then really your only option is to open up the intake manifold and clean those valves by hand.

Island Road · 08-22-2011, 11:48 PM

Had this problem, BMW covered it out of my warranty. Read here..

http://www.e90post.com/forums/showthread.php?t=549660

droptop335 · 08-26-2011, 09:21 AM

Quote:

Originally Posted by raceyBMW

AKA Italian Tune-up.

If your rough idle is caused by clogged or dirty injector tips, then a proper fuel injector cleaner should do the trick...but if its from valve stem build-up, then really your only option is to open up the intake manifold and clean those valves by hand.

I assume mine is due to the valve buildup issue and not a clogged injector(s) as I have never put anything but Chevron or Shell in the gas tank...plus my injectors were replaced just a couple of months ago.

Jeff@TopGearSolutions · 08-26-2011, 09:24 AM

Quote:

Originally Posted by droptop335

I assume mine is due to the valve buildup issue and not a clogged injector(s) as I have never put anything but Chevron or Shell in the gas tank...plus my injectors were replaced just a couple of months ago.

Injectors can still be clogged from name brand gas.

droptop335 · 08-26-2011, 09:36 AM

Quote:

Originally Posted by Jeff@topgearsolutions

Injectors can still be clogged from name brand gas.

Fair enough, I was just weighing the odds of one issue over the other

F1fletch · 08-31-2011, 05:05 PM

The new Toyota/Subaru Boxer engine will have port and direct injection as well.

PS My dealer said they are getting the tool for this walnut sheel intake blasting as well. It seems a good method...i will start saving now!

dlbrooks18 · 08-31-2011, 05:36 PM

Hmmm, rough idle, I bet all you need is new spark plugs, remind the dealer that you are due for new plugs under warranty at 45K.. that should fix it

drfrink24 · 08-31-2011, 08:50 PM

Quote:

Originally Posted by dlbrooks18

Hmmm, rough idle, I bet all you need is new spark plugs, remind the dealer that you are due for new plugs under warranty at 45K.. that should fix it

New plugs did nothing for mine.

Quisp · 09-01-2011, 08:04 AM

Had this problem and had the walnut shell along with hand cleaning by a dealership.....$$$$(but it did help tremendously)
This cleaning can be covered under warranty since it is a known issue which affects the car and is not a result of any type of misuse or neglect on the part of the owner. Just have to convince the dealership to submit the claim to BMW where it is handled on a case by case basis.

mithiral67 · 09-01-2011, 08:48 AM

Yea, I don't want to wait until there are symptoms of a problem. Just DIY it myself.

CALWATERBOY · 09-02-2011, 10:22 AM

Quote:

Originally Posted by Syndicategt

Take you IC pipe off to see another way gunk gets in there

InterCooler? Gunk in how?

Jeff@TopGearSolutions · 09-02-2011, 10:24 AM

Quote:

Originally Posted by CALWATERBOY

InterCooler? Gunk in how?

It's called blow by. Oil gets gunked in their and the charge pipe over time. Its part of the "emissions" system. Instead of dumping the oil particulate into the atmosphere they recirculate it back into the intake tract. That's the reason some of us run oil catch cans to reduce the amount of oil put back into their.

CALWATERBOY · 09-02-2011, 10:31 AM

Quote:

Originally Posted by GeorgiaTech335coupe

These cars burn a lot of oil, so there is a lot of crankcase gases. Build up can cause valves to not move as freely as they should.

I would've asked the dealer to explain why the type of gas you used affects carbon buildup. IMO, they love to make false claims to charge you. Always a good idea to test their knowledge.

Oil consumption is very low in a N54.

Rumor has it that routing the PCV line to atmosphere solves the problem in a major way. Gotta wonder if an inline plug's an inexpensive solution.

Catch can? ANYONE have pics of valves after 10K+ mi w/catch can?

Opinions on Redline's metal catch can vs. plastic?

08-22-2011, 06:55 PM	#23
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	It helps to run it all out on the highway, especially a car that is driven like a grandma, but inevitably their will still be carbon build up.
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08-22-2011, 07:44 PM	#24
Syndicategt Brigadier General 155 Rep 3,730 Posts Drives: 335i Join Date: Sep 2009 Location: Nor Cal iTrader: (11)	Take you IC pipe off to see another way gunk gets in there __________________ 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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08-22-2011, 08:07 PM	#25
JO3 Lieutenant 12 Rep 566 Posts Drives: a lot Join Date: Mar 2006 Location: CA iTrader: (8)	My car is in the shop right now to get the valves cleaned. I took pics of the valves, and they were pretty nasty. I'll post them up later. Also, for the OP, check out this thread if you want a TON of information about our crankcase ventilation system. http://www.e90post.com/forums/showthread.php?t=518306
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08-22-2011, 08:16 PM	#27
itsbrokeagain 310 Rep 15,745 Posts Drives: 1999 528iT, E53 X5, E46 325xi Join Date: Mar 2007 Location: Strong Island iTrader: (7)	I have done 4 of these as of latley...anything north of 50k i highly recommend doing it. LostMarines were super gunked up and he uses a lot of meth...we gained 12hp alone just from the cleaning on the dyno
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08-22-2011, 08:19 PM	#28
mave198 Lieutenant 11 Rep 452 Posts Drives: 2007 BMW 335i Join Date: Jul 2010 Location: Brooklyn NYC iTrader: (2)	Hey Matt...can u pm me a quote for cleaning out those valves???
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08-22-2011, 10:07 PM	#31
drfrink24 Second Lieutenant 13 Rep 233 Posts Drives: 2008 335xi Join Date: Apr 2011 Location: SE MN iTrader: (0)	My rough idle was fixed by running two back to back fuel system treatments by the dealer, under warrenty.
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08-22-2011, 11:48 PM	#33
Island Road Major 168 Rep 1,262 Posts Drives: 335i Join Date: Mar 2011 Location: Boston iTrader: (5) Garage List 2008 335i [10.00]	Had this problem, BMW covered it out of my warranty. Read here.. http://www.e90post.com/forums/showthread.php?t=549660
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08-31-2011, 05:05 PM	#37
F1fletch Private 5 Rep 86 Posts Drives: 335is Join Date: Aug 2011 Location: Ripon, Ca iTrader: (0)	The new Toyota/Subaru Boxer engine will have port and direct injection as well. PS My dealer said they are getting the tool for this walnut sheel intake blasting as well. It seems a good method...i will start saving now!
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08-31-2011, 05:36 PM	#38
dlbrooks18 Brigadier General 161 Rep 3,736 Posts Drives: e90 335i Join Date: Nov 2008 Location: Los Angeles iTrader: (2)	Hmmm, rough idle, I bet all you need is new spark plugs, remind the dealer that you are due for new plugs under warranty at 45K.. that should fix it __________________ 2008 E90 335
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09-01-2011, 08:04 AM	#40
Quisp Does not play well with others 80 Rep 1,787 Posts Drives: BMW Join Date: Apr 2007 Location: Arizona iTrader: (4)	Had this problem and had the walnut shell along with hand cleaning by a dealership.....$$$$(but it did help tremendously) This cleaning can be covered under warranty since it is a known issue which affects the car and is not a result of any type of misuse or neglect on the part of the owner. Just have to convince the dealership to submit the claim to BMW where it is handled on a case by case basis. __________________
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09-01-2011, 08:48 AM	#41
mithiral67 That guy 117 Rep 5,740 Posts Drives: 2015 Cayman GTS Join Date: Jun 2008 Location: Chicago Burbs iTrader: (4) Garage List 2015 Porsche Cayman ... [0.00]	Yea, I don't want to wait until there are symptoms of a problem. Just DIY it myself.
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