DIY Request: Walnut Blasting of Intake Valves

[theinfamousdrew]

After reading a lot of threads regarding the carbon build up on the intake valves Ive decided to do one of a few things.....

First try and get my dealer to do it under warranty.
If that doesnt work I would like to media blast it with walnut shells.

Ive seen people talking about getting it done but I would rather invest in the tools and do it my self.

Has anyone done this them selves?

Im thinking it should be pretty easy.

Thanks for any help!

[Dackelone]

Harbor Freight sells everything you need. The meadia blaster and the walnut shells(in two grades/sizes). Someone had posted a link in one of the old carbon buildup threads we had last year. I think using a bore-scope would also be a good ieda to see how bad your CB really is, before and after.

[theinfamousdrew]

Thanks for the response....

Ive read those threads and thats where I got the idea.

I was looking for a detailed DIY on the process.

[BostonBeemah]

Originally Posted by theinfamousdrew

Thanks for the response....

Ive read those threads and thats where I got the idea.

I was looking for a detailed DIY on the process.

+1 would like to also invest in some tools and do it myself... i would love to see a DIY if anyone has done this themselves

[theinfamousdrew]

Im worried about the media getting in the cylinder, other places it should be, or just making a huge mess.

this is what Im thinking.....

1-pull off intake mani
2 - use a tarp and tape to cover everything else
3 - tape off the cylinders that aren't at TDC
4- blast the crap out of them
5 - vacuum out the left overs
6 - turn crank to seal the remaining cylinders
7 - repeat steps 2 - 5
8 - clean up and install intake mani


Hows that sound?

[wolfe]

I can't confirm this is how BMW does it but I recall reading something similar to that from an Audi tech. They removed the manifold, rotated the crank by hand until the intake valves were closed, and used some cleaning chemical to soften the carbon (they let it soak for quite a while and reapplied it). I'd guess this may start to leak past the valves though eventually, and you may need compressed air to blow out all the debris/residue.

I wonder if anyone on 1addicts with access to the dealer computer system can pull the service information on this procedure.

[JefryHorizon]

Asked my ex-tech SA at the dealership today. He says it's per request and they don't deem it "necessary" as a means to maintain our cars. No details on the actual procedure but I have a feeling a few people I will be running into very soon would undoubtedly know.

[Satalite]

I usually drive my car short distances so it doesn't always warm up completely. I am at about 18k miles, would this be a good thing to talk to my dealer about before my warranty expires?

[SSSnakeman]

My buddy is supposed to stop at Harbor Freight tomorrow to pick up the stuff. I plan on doing this in a few weeks. Here is the thread I'm going off of.

http://www.e90post.com/forums/showthread.php?t=645616

[Guildenstern]

Originally Posted by Satalite

I usually drive my car short distances so it doesn't always warm up completely. I am at about 18k miles, would this be a good thing to talk to my dealer about before my warranty expires?

It's a Direct Injection problem associated only with the Turbo Engines like the N54/N55/N20/N63 etc...

It's not a problem with the regular Naturally aspirated engines such as the 128's N52 (and or N51) Just use a top tier detergent gasoline or drop a bottle of techron in your tank regularly.

Our engines spray the detergent fuel onto the intake valves, where as in direct injection the fuel is mixed inside the cylinder and so the intake valves on DI engines can get fouled up by crank case re-circulation gas fed back into the intake.

[Satalite]

Originally Posted by Guildenstern

It's a Direct Injection problem associated only with the Turbo Engines like the N54/N55/N20/N63 etc...

It's not a problem with the regular Naturally aspirated engines such as the 128's N52 (and or N51) Just use a top tier detergent gasoline or drop a bottle of techron in your tank regularly.

Our engines spray the detergent fuel onto the intake valves, where as in direct injection the fuel is mixed inside the cylinder and so the intake valves on DI engines can get fouled up by crank case re-circulation gas fed back into the intake.

+1 thanks for the explanation!

[DriveHard]

Originally Posted by theinfamousdrew

After reading a lot of threads regarding the carbon build up on the intake valves Ive decided to do one of a few things.....

BMW does not consider the cleaning of the valves as a Maintenance or Warranty matter, although it has been done in extreme cases..

Having BMW do it as a preventive measure, in my opinion will not happen..

BMW has devised a Special tool / Equipment / procedure when a dealer does do it..

First it does require the removal of the intake manifold. The special tool sucks and blows at the same time thre a special fitting that fits tightly over the intake port.. A vacuum is applied to the fitting and there is a small port that allows a wand to enter the fitting and spray the valves with the walnut shells.

The cylinders have to be at TDC when doing so. There is no chance of getting shells in the combustion chamber. The port has to be thorougly cleaned after removal of the special fitting.

It is very time consuming ( about 3+ hours to do 6 cylinders. )

The media that BMW specified is special.. It is very fine. I dont know how it compares to stuff you get on the outside..

Forget about "ordering" the tool from BMW $$$$ wise... especially if one is doing it "just in case"


A personal note: the build up happens more to what one would call "station" cars... meaning very short trips / start stops / etc.. Cars that have been.....well lets say...Driven Hard ( pun intended) dont seem to suffer as much.. I also feel that this is in inherent design flaw. ( for all manufacturers )

The simple fact that the valve stem is HOT and lubricated leads itself open for accumulation over time.. The carbon build up is simply the oil used to lubricate the valve stem and also the residual oil that circulates thru the intake manifold thru the crank case vent valves (aka PCV valves for us old timers)

There are more failures of Crank case vent valves then i care to count.


I dont think this is one of those good / easy DIY's my .02

Regards,

Alex

[flzrider]

Originally Posted by DriveHard

BMW does not consider the cleaning of the valves as a Maint or Warranty matter, although it has been done in extreme cases..

Having BMW do it as a preventive measure, in my opinion will not happen..

BMW has devised a special tool / Equiptment / procedure when a dealer does do it..

First it does require the removal of the intake manifold. The special tool sucks and blows at the same time thre a special fitting that fits tightly over the intake port.. A vacuum is applied to the fitting and there is a small port that allows a wand to enter the fitting and spray the valves with the walnut shells.

The cylinders have to be at TDC when doing so. There is no chance of getting shells in the combustion chamber. The port has to be thorougly cleaned after removal of the special fitting.

It is very time consuming ( about 3+ hours to do 6 cylinders. )

The media that bMW specified is special.. It is very fine. I dont know how it compares to stuff you get on the outside..

Forget about "ordering" the tool from BMW $$$$ wise... espically if one is doing it "just in case"


A personal note: the build up happens more to what one would call "station" cars... meaning very short trips / start stops / etc.. Cars that have been.....well lets say...Driven Hard ( pun intended) dont seem to suffer as much.. I also feel that this is in inherent design flaw. ( for all manufacturers )

The simple fact that the valve stem is HOT and lubricated leads itself open for accumulation over time.. The carbon build up is simply the oil used to lubricate the valve stem and also the residuial oil that circulates thru the intake manifold thru the crank case vent valves (aka PCV valves for us old timers)

There are more failures of Crank case vent valves then i care to count.


I dont think this is one of those good / easy DIY's my .02

Regards,

Alex

Thanks for the info. Do you work at a BMW dealership? If not, how did you come across such detailed information?

[DriveHard]

Originally Posted by flzrider

Thanks for the info. Do you work at a BMW dealership? If not, how did you come across such detailed information?

ancient Chinese secret

[Dackelone]

Originally Posted by DriveHard

BMW does not consider the cleaning of the valves as a Maintenance or Warranty matter, although it has been done in extreme cases..

Having BMW do it as a preventive measure, in my opinion will not happen..

BMW has devised a Special tool / Equipment / procedure when a dealer does do it..

First it does require the removal of the intake manifold. The special tool sucks and blows at the same time thre a special fitting that fits tightly over the intake port.. A vacuum is applied to the fitting and there is a small port that allows a wand to enter the fitting and spray the valves with the walnut shells.

The cylinders have to be at TDC when doing so. There is no chance of getting shells in the combustion chamber. The port has to be thorougly cleaned after removal of the special fitting.

It is very time consuming ( about 3+ hours to do 6 cylinders. )

The media that BMW specified is special.. It is very fine. I dont know how it compares to stuff you get on the outside..

Forget about "ordering" the tool from BMW $$$$ wise... especially if one is doing it "just in case"


A personal note: the build up happens more to what one would call "station" cars... meaning very short trips / start stops / etc.. Cars that have been.....well lets say...Driven Hard ( pun intended) dont seem to suffer as much.. I also feel that this is in inherent design flaw. ( for all manufacturers )

The simple fact that the valve stem is HOT and lubricated leads itself open for accumulation over time.. The carbon build up is simply the oil used to lubricate the valve stem and also the residual oil that circulates thru the intake manifold thru the crank case vent valves (aka PCV valves for us old timers)

There are more failures of Crank case vent valves then i care to count.


I dont think this is one of those good / easy DIY's my .02

Regards,

Alex

Thanks for the info AND for posting this!


So... just bc I am the curious type.... How does one know when your crankcase vent goes bad?

Dack

[Mark Attack!]

I took my car in for service last September because my power would cut out around 5k at WOT (running Cobb). At the time I thought it was just the maps I was running. The dealer took it for several test drives and confirmed the problem even without the tune. Long story short, they kept my car for 3 days just removing the carbon buildup! I don't remember their exact process but I'm pretty sure it was similar to seafoam. He told me it was so bad that each day they would spray it down and let it soak over night before chipping away and removing the buildup. I only had 23k miles on the at the time of service. That's why these types of threads really interest me... Before warranty is up I intend to take it back and request the service be performed again. Does the fact that I only have access to 91 octane contribute to the problem? I only run a tune and I'm a fairly conservative driver.
Sorry didn't mean to jack the thread. But IMO everyone should ask the dealer to look at the carbon build up. We all know every dealer is different

[DriveHard]

Originally Posted by Dackelone

Thanks for the info AND for posting this!


So... just bc I am the curious type.... How does one know when your crankcase vent goes bad?

Dack

your welcome//

oil leak / suction noise / warning light on as its a lean condition

[flzrider]

So aside from installing a catch can and avoiding short duration trips, is there anything else that can be done to prevent carbon build-up? Is there an EGR (exhaust gas recirculation) that can be blocked off?

[DriveHard]

Originally Posted by Dackelone

Harbor Freight sells everything you need. The meadia blaster and the walnut shells(in two grades/sizes). Someone had posted a link in one of the old carbon buildup threads we had last year. I think using a bore-scope would also be a good ieda to see how bad your CB really is, before and after.

DACK, I was able to dig this up..

The media is 20/30 SAE or 0.45-0.80mm walnut shells that can be sourced locally

Marco marcousa.com/index.cfm or www.trinco.com or www.mcmaster.com

Here are the instructions ( disreguard the N73 instructions as its the same for all engines )

BTW the "dirty" valves shown in this guide are no where near the really bad stuff that i have seen .. im talking chunks ...

[Dackelone]

^^Good stuff!!

[flzrider]

DriveHard, thanks for the doc!

Alot of other good information regarding media blasting their intake ports can be found at the following link: http://www.e90post.com/forums/showthread.php?p=11658312

[Shaggykjb_135I]

walnut shells in the intake scares me...try Seafoam.