Removal of Carbon Deposits

[Gator325525]

Has anyone ever had their engine serviced to remove carbon deposit build-up? A casual acquaintance who also has an N54 powered E92 was telling me he took his car to a shop up in Georgia that specializes in cleaning carbon deposits from euro-cars.

The guy tells me he noticed a huge difference in how the engine performs and its economy, but I'm somewhat skeptical and thinking maybe it's all in his head.

Can anyone speak affirmatively to the benefits of carbon deposit removal?

[mryakan]

guys in the e90 section seem to say it works.

[Rudolph320i]

at best they put fuel system cleaner through it with, possibly, some oil additive to help clean things up. other wise they took your friends car out and spent a few minutes at WOT.

[mryakan]

at best they put fuel system cleaner through it with, possibly, some oil additive to help clean things up. other wise they took your friends car out and spent a few minutes at WOT.

Not true. The procedure for the N54 engine is to clean the carbon buildup using walnut blasting.

[BimmerBreaker]

They probably charge like $500 and throw a bottle of seafoam in the car

[Rudolph320i]

Not true. The procedure for the N54 engine is to clean the carbon buildup using walnut blasting.

oh god we still do that? didnt GM do that in the late 70s and early 80s?

[ElleShooTiger]

other wise they took your friends car out and spent a few minutes at WOT.

Italian tune-up FTW!!

Just floor it a few times a week, or day, and your engine will LOVE you!

[HoJo]

Not true. The procedure for the N54 engine is to clean the carbon buildup using walnut blasting.

This is the only way to clean a N54. You can add all the fuel system cleaner you want, but since it's a direct injected motor it won't clean anything before the cylinder. The N54 has an issue with carbon buildup on the intake valve and the runner right before the valve.

[Crusher47]

Italian tune-up FTW!!

Just floor it a few times a week, or day, and your engine will LOVE you!

[slocar]

Italian tune-up FTW!!

Just floor it a few times a week, or day, and your engine will LOVE you!

This. I don't know if BMW still does it, but back in the day the owners manual used to say if you drive in traffic for a while at low revs, first chance you get to drive for a few minutes at 3000 rpm or more.

[mryakan]

This. I don't know if BMW still does it, but back in the day the owners manual used to say if you drive in traffic for a while at low revs, first chance you get to drive for a few minutes at 3000 rpm or more.

Guys, as stated, this will not work on the N54. Direct Injection introduces new issues that are not the same as engines of late. Stopping giving useless advice to the OP.

[White94RX]

+1

N54's are a completely different animal

[Rudolph320i]

ill just point out here, that ever since we moved fuel delivery down from the top of the intake to the actual port, the only think an italian tune up would help was carbon buildup on valves, not intake runners. that stuff worked on throttle body injected and carb'd engines because the fuel got all over everything in the intake.

[mmawolverine]

theres got to be a cheaper way to diy it, bg makes great products that ive used on other bmw engines like bg109, bg44k, and the their intake manifold cleaner

[marine24]

I cleaned my intake ports using carbon cleaner and a brass wire brush on my N54. Not as good as a blasting but it help a lot. I noticed a big difference afterwards. It is more labor intensive but the end result was great for the price ( about $50 in supplies and 4 hours of time). Make sure the engine is cold when you do.it though or the carbon cleaner will just boil off with no effect

[art@rmeuropean]

CRC now makes a product just for cars with direct injection. You basically remove the intake box, stick a straw past the MAF sensor and spray it into the intake while the engine is running at 2K rpm. Here is a link to our product page if anyone needs to order it: http://www.rmeuropean.com/Part-Numbe..._28EAE8E9.aspx

[mhunter29928]

It's an unintended consequence of direct injection + turbocharging. I have done several walnut shell blastings. It's the only "right" way to do it.

[E39Chris525i]

My local $tealer is advertising this for $500 vs an Indy for $450. What do typical shops charge for this? I've got about 27k on my N55 and IMHO, BMW should do this under the maintenance plan.

[modular93fox]

It's not a maintenance item because it's not something that wears out... It's just a problem and problems get delt with when they become a problem.
Your looking about 5 hours or so... Whatever the book says to remove and replace the intake manifold plus 2 hours for carbon cleaning. So minimum 4hr likely 5ish. Lucky you don't have the v8 turbo.. Gotta pull the engine to do that job. Those cars will be sold cheap when they get those estimates lol.

[timsev]

It's an unintended consequence of direct injection + turbocharging. I have done several walnut shell blastings. It's the only "right" way to do it.

This. Sure, you can DIY the process with shitty wire brushes and brake cleaner like some people have tried but the method risks damage and it does not get everything clean. For $500 or less, it's totally worth it to have a professional do the work and get the valves spotless. I've done one N54 and it was a pain in the ass and I don't want to do it again. If you can afford to drive a nice car like a 335i, you can budget for proper maintenance. No, a spray can of cleaner will not do the job correctly.

[BimmerBreaker]

They do the walnut blasting in situ now, don't they? $500 isn't really that bad for the amount of work thats done. Guess it got cheaper since they were doing so many they had to find a way to make it reasonable to do. I expect in a few years shops will be doing this for $300 as the cars themselves get cheaper and cheaper. Other than HPFP and etc it seems like these engines are proving to be pretty reliable.

Also don't think I'll have this problem in my N52 but I'm looking forward to having this problem in the future once I'm in an N55 powered car

[Critter7r]

FYI, not all engines will require this service. My personal opinion on this (backed by absolutely nothing but anecdotal evidence) is that cars that are short-tripped frequently will need it more than vehicles that are driven for 30 minutes or more at a time frequently (as in, "daily"), similarly to older vehicles that get clogged CCV systems.

[Rudolph320i]

FYI, not all engines will require this service. My personal opinion on this (backed by absolutely nothing but anecdotal evidence) is that cars that are short-tripped frequently will need it more than vehicles that are driven for 30 minutes or more at a time frequently (as in, "daily"), similarly to older vehicles that get clogged CCV systems.

While this could effect how fast the carbon builds up, oil vapors are still pulled into the intake via CCV and the valves are still not washed by anything. So eventually it will be built up enough to hurt airflow and power.

[BimmerBreaker]

I think what we need is effectively a CCV delete. VW guys have had something that deletes their CCV (or EGR) equivelent to prevent this sort of buildup on certain engines of theirs. I don't think we really need the oil vapors in the combustion chamber, its just designed to suck it in to combust it to make it more emissions friendly so its not dumping excess oil vapor out everywhere nor is there pressure from vapors building up anywhere.

Quick Google of VW EGR delete shows they have a few options for this and its really common to do. I wonder why something has been developed for BMWs yet.

[ptarditi]

I think Burger (or whoever makes the JB4) has a catch can system for the N54, I know a few techs who have 335s and have them installed. Walnut blasting was first used by BMW on the e21, with k-jet (kontinuous injection) so I think its more of a problem then just washing the valves clean.