[Pylon]

I am waiting in agony to get my hands on a new 335i at the end of June and I had a question about Direct Injection and carbon build-up. Have any of you had to take your cars into BMW to have the valves cleaned due to excess carbon build-up? If yes, at what mileage?

[MSPORTWORLD]

This is a great question since the detergents in premium fuel do nothing to clean our valves cause of DI.

Free bump to see if anyone has a response to this.

[per]

A friend of mine had problems with carbon build up at 30000 km, he did get missfires at high rpm, he changed the injektors and sparkplugs, but still have some problems.
He probably has to clean the valves also.
My brother in law ho is responisble of the development of volvos new turbo engines told me that the carbon buildup was caused by the high temps and the raised internal pressure . the only solution would be to get the temp down, Meth maybe?

[Ramos]

Yes plenty of people around here have had this problem, do a search..
At some point, it was labeled the 2nd HPFP issue... cuz there was a new case on here every week.. I think most people who had the issue were around 20-25K miles and it seemed to affect tuned cars more than stock cars

[Quisp]

It has been called coked valves.

here is a linkk to thread with some more info

http://www.e90post.com/forums/showth...47781&page=193

Post 4233
there are even some pictures after that
Meyerguru is the man that is wise about this topic

[hun77777]

will fuel enjector cleaner thingy help?

[MFKN3]

What about those fuel additive cleaners like spitfire? I remember VW used to give me a VW cleaner in my car at services

[Ilma]

Originally Posted by hun77777

will fuel enjector cleaner thingy help?

If the injector cleaner is added to the fuel.....AND the fuel is directly injected into the cylinder......THEN how is it going to clean the intake valves of soot/oil residue?

The point of discussion is that the problem of carbon build up exists because there is no fuel being injected through an intake port......it's going directly into the combustion chamber.

So I can't see how any type of injector cleaner would help with anything except for padding the profit margin of whoever sells it to you.

[Ilma]

Originally Posted by xsboost

What about those fuel additive cleaners like spitfire? I remember VW used to give me a VW cleaner in my car at services

That would help with cleaning the fuel injector nozzles themselves......not the intake valves.

Same reason as above.

[Drakos]

Shell gas stations now use Nitrogen additive in their fuel. It is supposed to provide cleaning properties to reduce buildup on the valves and pistons.

[Curt2000]

I think you can put 'Sea Foam' brand stuff into your intake manifold.

[cbad335]

Originally Posted by Drakos

Shell gas stations now use Nitrogen additive in their fuel. It is supposed to provide cleaning properties to reduce buildup on the valves and pistons.

Again, see Ilma's posts (#'s 8 & 9).

[Ilma]

Thank-you....I hope that point gets across now.

But the seafoam idea......hmmmm that sounds interesting.

Anyone have any details on this?

Do you inject it directly into the intake manifold?

If so, then I could see some potential to clean up those valve stems.

[BOOST3D]

i think you an hook the seafoam stuff to a vac line ad get it to clean the manifold and valves

[Zeph]

This is very interesting, it might be a good idea for all N54 owners to clean their heads/valves every so many miles (30k?) since we don't get the normal detergent and fuel system cleaners to do the job. Or is this only a problem with failed fuel pumps and running lean?

[Phase Loc]

Just got my 2007 335i back from dealer after almond shell cleaning of carbon build up on intake valves, mileage on car 47,109. Car was at dealers in February same problem , same solution, car mileage 44,716. That's 2,393 miles between coke ups! I use Shell or "76" 97 octane gas. Also had 4 high pressure fuel pumps replaced since car was new. This is totally unacceptable for a car of this caliber. Dealer tells me the coking up "It's normal" My extended warranty runs out in November. Gonna get rid of car.

[Patrick303]

Thanks for dragging up a 3 year old thread just to tell us you're going to sell your BMW as your first post on this board!

[Eric335]

Originally Posted by Patrick719

Thanks for dragging up a 3 year old thread just to tell us you're going to sell your BMW as your first post on this board!