Walnut Blasting?

[Frupal]

Anyone done this? I just heard of it and it looks like our engines might need it.

[Opie55]

My son had it done on his N54 engine - a precursor engine to yours. As far as I know, it's an issue with any direct injection engine because there is no gas to wash down the valves. But for whatever reason I have not seen it discussed much on this forum. On an engine like yours it's not a huge job. I've had the intake manifold off on an N54. But on the N63 it's way more complicated because of the "Hot V" configuration because there are two intake manifolds that are way down low on the sides of the engine.

[JBF650]

Originally Posted by Frupal

Anyone done this? I just heard of it and it looks like our engines might need it.

You know Frupal, I thought this was a bit of tongue in cheek ages ago when I saw a thread on it .... walnut blasting... wtf? Why and what are we blasting with walnuts... however you are spot on ! I just read an article as well on the potential need to do this on our V8’s due to valves getting gummed up if not driven hard and regularly... essentially because our engines are direct injected into the combustion chamber the fuel doesn’t ‘wash’ build up off the valve stems.
well pays to drive our cars more often huh!

[ezmaass]

This is a very popular procedure for us R8 owners - both V8 and V10 suffer from carbon build-up over time. Most owners will have it done somewhere around 20k - 40k miles. The procedure, again on an R8, typically costs around $1k - $1.2k. I'm not yet at this point, so I haven't done it personally.

Depending upon the engine design, sometimes they can get a scope in there to see the carbon build-up. Some engines don't permit taking that peek, so you need to get it apart first.

I've not read up on it with regard to N55 or N63, but as Opie said, you typically find it with most direct injection systems. I've never, however, had the procedure done on any of my previous BMWs, so I doubt I'll be starting with the 6 (especially considering I'm just now at 10k miles on the clock). If you plan to keep the car a long, long time, and you want to maintain every bit of power, it's an important procedure. Again, why it's popular with a lot of the R8 owners I know - and why I'll eventually do it, myself, on that car. But short of that, I'm not sure I'd do it on a DD unless you're way up there in mileage and beginning to experience some problems.

As far as effectiveness? It's very effective. If you see the before and after shots of the valves, they'll look black and caked with carbon and then afterwards clean, shiny metal.

[Opie55]

I think my son paid about $350 US at an indy on his N54. Again, not a huge job on the inline 6. But I don't think I'd consider it before 50k miles - probably more like 75k - and even then only if it idled rough or felt sluggish. I'm not sure that driving hard or often makes much difference.

[e38740imd]

its a night and day difference. once done. (testimonial based on the n54) the car was driving fine but you just wont know what power and driveability will be missed until you do it because the build up is so gradually you wont know it happening. n54 had about 100k miles when it was done. 40 thousand miles later still packs a punch (e60 535i)

[Opie55]

Originally Posted by e38740imd

its a night and day difference. once done. (testimonial based on the n54) the car was driving fine but you just wont know what power and driveability will be missed until you do it because the build up is so gradually you wont know it happening. n44 had about 100k miles when it was done. 40 thousand miles later still packs a punch (e60 535i)

The E61 was done at about 60,000 k and little noticeable difference. The buildup varies a lot from car to car.

[e38740imd]

Originally Posted by Opie55

The E61 was done at about 60,000 k and little noticeable difference. The buildup varies a lot from car to car.

correct. our 535i barely saw any highway use. but didnt need much attention for maintainance. just did spark plugs and hpfp.

how ever the turbos are starting to leak. that will be dealt later

not sure how my 640 is at 48k. ill do it later when the mileage doubles. this car is always on the highway

[$howtime456]

I have did this last year at 75k. Valves were caked up. After was smoother idle.

[MichaelInChicago]

Is walnut blasting the best way to go? Are there other and potentially better ways to remove carbon buildup?

If the car is still under warranty, are we required to go to a BMW dealer to have this service done?

[Opie55]

Originally Posted by MichaelInChicago

Is walnut blasting the best way to go? Are there other and potentially better ways to remove carbon buildup?

If the car is still under warranty, are we required to go to a BMW dealer to have this service done?

Walnut blasting is considered the best way. You'd have to ask your dealer if they even do it. Some use chemicals. You are not required to have work done at a dealer to preserve your warranty. If you go elsewhere, make sure they have done it before. You have to rotate the crank as you do each cylinder to make sure the valves are fully closed or you will have a combustion chamber full of walnut shells. But if you do get an estimate on an N63, please share it. It will be in the thousands.

[Derekz4]

Had anyone tried a can of CRC intake valve cleaner?

[Opie55]

Originally Posted by Derekz4

Had anyone tried a can of CRC intake valve cleaner?

How is it applied? Directly to the valves after removing the manifold or through the intake or mixed with gas? If it goes where the gas goes it won't help a direct injection engine - the gas never touches the valves.

[Opie55]

I looked at the CRC site. It is sprayed through the intake so it indeed would wash over the valves. But I have a hard time believing it would do much of anything. If you have ever seen pics of some BMW valves that need Walnut blasting, the caked carbon can be a quarter inch thick - and hard enough that it needs to be media blasted. There is no way a chemical sprayed from a distance will dissolve all that. Maybe if you used a can every few thousand miles from new or something, but if that was the miracle solution for older cars we would know that by now and nobody would walnut blast. Plus, since you can't see in there you would have no way to know if it did anything.

[MichaelInChicago]

It does seem too good to be true, but unless many people are suffering from the placebo effect, the reviews have been excellent, with many people saying how much better their cars are running after the use of this product.

[Opie55]

Have not looked at the site in that much detail, but I'd need to see real-world before and after photos of actual valves. If the product could actually remove that kind of buildup, CRC would have posted that by now, don't you think?

[Derekz4]

I’m wondering if one of Snap On borescopes are able to make it through the intake manifold to see the valves.

[Derekz4]

https://www.e90post.com/forums/showthread.php?t=927945

Good read.

[Opie55]

Originally Posted by Derekz4

https://www.e90post.com/forums/showthread.php?t=927945

Good read.

On a 640, probably. Not sure about a 650.

[Russbmw]

Here's a bit more info from when I had my 335i done

https://www.e90post.com/forums/showt...ghlight=Walnut