DI and carbon build up

[RPM90]

Here's an interesting thread with a possibility it might be happening to our DI engines as well.

http://www.audizine.com/forum/showthread.php?t=336352

Has anyone checked their engine?

Veeerrrrry interrrresting.

[BrokenVert]

Has this happened on any other DI engine? like Fords or Porsches?

[onefastman]

Just use seafoam and forget about it.

[Lionel Hutz]

Originally Posted by onefastman

Just use seafoam and forget about it.

If the problem were as simple as seafoaming your engine, you wouldn't see those RS4 owners tearing their engines apart every 30,000 miles. With DI, fuel doesn't get sprayed where there is carbon buildup, so fuel system cleaners don't touch it.

Likely carbon buildup is not such an issue for the N54 because it runs so hot compared to those Audi engines. Still, when I was test driving CPO cars I noticed substantial power variations between cars. That's a sign of potential carbon buildup issues, or software faults/fuels system issues (which, let's be honest, isn't uncommon with the N54).

[Dackelone]

A friend of mine has a RS4. He installed a oil catch can of his own design. He is a Mechanical Engineer and loves tinkering with his cars. He tells me you wouldn't believe how much oil he collects with his CC every few weeks. Makes me want to install a CC on my N54.

I wonder if anyone has used Seafoam or LiquMolly intake manifold cleaners on thier cars. Basically you spray the foam inside of the intake with the engine idling, an dthen you rain the RPMs to burn off the 'foam" and carbon buildup. I used it in my old bmw - worked well. The LiquMolly stuff came with a one meter long flexi hose to slide up inside of the intake manifold.

Yes, some engine designs are just plain bad. The RS4 might be one. Old Subbie flat sixes were also very "sensitive" to carbon buildup over time. I knew of alot of Subbie techs that simply sucked some cold water thru a vacum hose to "cold shock" the carbon build up off the Subbie intake valves. Worked like a charm. You had to be carefull not to let the engine drink too much. You only wanted a small spray of water and NOT a gulp! We all know water doesn't compress when it meets Mr. Piston!!! lol

[DBFIU]

That carbon buildup is UNREAL. Did you see those pictures?

scroll to the middle of the page,

http://www.audizine.com/forum/showth...p-amp-Clean-Up

[Cuz5150]

Our engines(N-54) will develop this carbon buildup, Everyone needs to get friendly with Seafoam. I'm planning on installing a vacuum line or 2 from the intake manifold. I will try to install these vac lines permanently. Will plug them with golf tees, when not in use and tuck them away under the hood. The best time to use seafoam, is before an oil change. Seafoam the engine, take if for a 10min drive, come back THEN do an oil change....
Seafoam is GOD in ANY engine.............mmk?

[BrokenVert]

Originally Posted by TrackRat

Seafoam is a fad. Techron is an approved carbon cleaner by BMW and other Euro car makers.

I contacted them about whether or not Techron would work with DI engines. They said yes

[DBFIU]

Originally Posted by Cuz5150

Our engines(N-54) will develop this carbon buildup, Everyone needs to get friendly with Seafoam. I'm planning on installing a vacuum line or 2 from the intake manifold. I will try to install these vac lines permanently. Will plug them with golf tees, when not in use and tuck them away under the hood. The best time to use seafoam, is before an oil change. Seafoam the engine, take if for a 10min drive, come back THEN do an oil change....
Seafoam is GOD in ANY engine.............mmk?

Do you have any field data that proves carbon will buildup in the N54? Just because Audi and BMW both use DI doesnt mean they will both build carbon.

Show me some proof that will happen.

[NYC6]

Originally Posted by BrokenVert

I contacted them about whether or not Techron would work with DI engines. They said yes

My Vette gets a bottle every 1000. My 135 just passed 1000 and I picked up a bottle for it yesterday. It will go in the next fill up.

[Cuz5150]

Originally Posted by DBFIU

Do you have any field data that proves carbon will buildup in the N54? Just because Audi and BMW both use DI doesnt mean they will both build carbon.

Show me some proof that will happen.

135i owner about 2yrs ago had to get a new engine, he posted some picks as the engine was taken apart.......you should have seen CB...mmk?

[AchtungF80]

I think this thread is going in 2 places here.
I should make this clear. There is fuel injection cleaner and then there is sea foam.

Sea foam apparently can do both of the following...We are talking about 2 different ways of applying sea foam.
1.) in gas at fill-up
2.) via vacuum line directly into intake manifold.

The question is, how many of you are doing both?

[BrokenVert]

Originally Posted by TrackRat

FWIW all DI engines build carbon in the cylinder because of the DI process. You can probably find some useful tech info. at SAE.org. The car companies are all looking for ways to reduce the unusual carbon build up in DI engines.

link? I have 30K miles on my car and both I, and my father have noticed decreased power out of my car. I was thinking HPFP issues again, but this might also warrent some consideration.

[DBFIU]

Originally Posted by Cuz5150

135i owner about 2yrs ago had to get a new engine, he posted some picks as the engine was taken apart.......you should have seen CB...mmk?

Just one owner had this problem?

[onefastman]

seafoam in the gas does nothing because of the di. check on e90post where mr.5 does a great diy. All you do is keep the engine reved above 2K (people recomend 4K) and slowly suck it in into the vaccum line on the diverter valves very slowly and watch the smoke show.

[BrokenVert]

Originally Posted by onefastman

seafoam in the gas does nothing because of the di. check on e90post where mr.5 does a great diy. All you do is keep the engine reved above 2K (people recomend 4K) and slowly suck it in into the vaccum line on the diverter valves very slowly and watch the smoke show.

Did this on my 01 Mountaineer at the 120K mile mark. Its crazy what comes out of the tailpipe.

[oneintheory]

had carbon buildup twice on mine.

[Mark M]

OneInTheory.......Can you elaborate?

How did you know there was buildup? Did you feel knocking, loss of power, Check engine light? What was your mileage?

Was there a BMW service bulliten for this? If so do you have a description of work performed?

Thank you.

[oneintheory]

Originally Posted by Mark M

OneInTheory.......Can you elaborate?

How did you know there was buildup? Did you feel knocking, loss of power, Check engine light? What was your mileage?

Was there a BMW service bulliten for this? If so do you have a description of work performed?

Thank you.

loss of power, CEL. first time, approximately 20k. second time, approximately 25k.
no bulletin, they took the top half of the engine apart. i got new plugs, new injectors, had carbon buildup cleaned out of the intake mani and cylinders 5 & 6, and the obligatory new HPFP. i think there were a couple more things, but i don't have the record in front of me. they might have had to send the head off the second time to be remachined, but I'm not positive. ugh.

[Mark M]

Wow...thank you for the prompt reply. This is certainly unnerving news.

For those of us intending to keep the 135 for many years to come, this raises an eyebrow.

With over 25k miles, I assume the bulk of your driving is long trips that should cause the engine to reach desired operating temps.

I could understand excess carbon buildup if your daily commute was only 5 miles as this does not allow the engine time to come up to temperature.

Anyone else with similar observations?

[m6pwr]

There is also a thread on this on the BITOG (Bob is the Oil Guy) forum:
http://www.bobistheoilguy.com/forums...95#Post1574495

If this link doesn't work, the gist of it is that the problem is associated with turbo charged direct injected engines that have a tendency to cook the oil pretty good: Audis, MazdaSpeeds, MINIs, and maybe N54 BMWs. Puttting any thing in the gas doesn't help since the valves never see gas, only air and the oil vapors sucked up from the crankcase. I checked with the SA at my BMW dealer and he said they are starting to do valve/intake cleanings not only on N54 motors but also on the MINI engines, and he says they have had to pull the heads of several MINI engines to manually remove deposits. Don't know whether the service is really necessary or not, or just something they sell.

[oneintheory]

Originally Posted by Mark M

Wow...thank you for the prompt reply. This is certainly unnerving news.

For those of us intending to keep the 135 for many years to come, this raises an eyebrow.

With over 25k miles, I assume the bulk of your driving is long trips that should cause the engine to reach desired operating temps.

I could understand excess carbon buildup if your daily commute was only 5 miles as this does not allow the engine time to come up to temperature.

Anyone else with similar observations?

the bulk of my driving is and has always been trips of less than 30 minutes.