Walnut Blasting (or lack of) symptoms.

[davemohan]

Let’s say I’ve got at 2008 135i (N54) with about 120,500 miles. Let’s also say that it is somewhat modified with a Dinan Stage 3 tune and various related and unrelated mods. Still has the original PCV valve and does NOT have a catch can. And finally, let’s say that it has definitely never had a walnut blasting or similar procedure done.

All hypothetical of course, but in such a case what symptoms should I be seeing due to the lack of walnut blasting? I've searched and there is a lot of info on why and when you should do walnut blasting, and lots of nasty looking photos, but I could not find anything on what the noticeable problems are if you don't do it. The boost looks the same as always on my direct read (not OBD) gauge, no rough running, lag, or reduced acceleration, basically seems to be running great. I hate to do an invasive procedure like this unless it is necessary. Any insight would be greatly appreciated! Thanks!

[iminhell1]

Hypothetically if you had this car, you've not maintained it well.
Best of luck.

[ShocknAwe]

If the idle is totally smooth, no misfires, afr is perfect, and no leaks, then by all means, continue as normal. But you'll likely pick up ~40whp cleaning the valves. So keep that in mind.

Things I'd like to point out:

1. Catch cans have not been shown to reduce buildup. They have been adopted by the community as a why not, couldn't hurt kind of mod, and via scare tactics of some vendors. Definitely not necessary, or even substantiated in any way.

2. Intake cleaning is ideal but only necessary if the car shows signs of gummed up valves.

3. Only reason to replace the pcv is if the old one is worn out or clogged. See point #1 and #2. If replacing, there are several alternatives to stock which will hold up better over time.

This (catch can and pcv) all goes back to the whole premature "preventative" replacement of the water pump. Why replace it at 50k if it could go until 90-120k? If you can, I would go ahead and have the valves cleaned by someone who wont dick the job up. It'll help. Skip the rest.

[1and1]

You may not be feeling the symptoms as they have grown slowly over the life of the car. However, if you were to clean them you would notice the improvement- everybody does.

Air flow is being restricted and flow path is no longer smooth, resulting in somewhat less air flowing in a poor pattern- it's not idling as smooth as it should tho if may feel "fine", and power will be down- burn characteristics are really poor at this point.

Think of it as a light case of asthma....

And nope, I really don't think your's is a unicorn N54 that doesn't have dirty intake valves at 125+K miles. I am glad it's not stumbling all over itself, but you're approaching around double the mileage where I'd encourage having the job done.

[asiflicious]

I had the walnut blast done on my 335i at like 65k miles. I didn't feel a difference. But at 120k I'm sure you will. I agree with above about the OCC and PCV. No substantial evidence the OCC does anything

[davemohan]

I want to say thanks for the replies!

In order, the car is extremely well maintained, but I need a real reason to perform maintenance, particularly if it is something (like walnut blasting) that I'm not comfortable doing myself. Major maintenance at 60k, numerous replacements at 90k, time for another 60k maintenance which is what got me to thinking about this. Thanks, but don't need any luck, never believed in it!

@ShocknAwe - This is pretty much what I was thinking, looking at the intake tracts they are certainly not sparkling clean, but it is not what I would consider "build-up" that is interfering with flow. At this point I'm pretty much seeing the walnut blasting the same way you describe catch cans. And "blasting" powdered medium into your intake tracts, no matter how well you're cleaning up after, is not to be taken lightly. As to the valves and seats, considering direct injection, probably overdue for cleaning. If you are in Charleston, SC is there anyone you could recommend? I'm in the Fort Mill area, but I'm used to traveling for quality service.

@1and1 - As I said above, I agree that the valves and seats should be attended to. The problem with results that everybody feels (but nobody measures) is the psychological factor. I just spent a wad of cash to improve my performance, and by god I DO feel a difference! (And btw, you have the same cars in your garage that we have, except mine's an 08 and hers is a 14. Excellent choices!)

And finally, a case where no difference was felt at 65k kind of reinforces my opinion, particularly when what you hear is that it MUST be done every 30k-40k. According to local mechanics, the N54 PCV valves do have a tendency to fail, and this may be the cause of some of the extreme build-up some people have seen. I'm going to replace mine with an aftermarket as a precaution.

Again, thanks for the replies!

[ilikebmxbikes]

After walnut blast my throttle response improved. I didn't think I needed it but after I did it I was very happy.

[Gizmo135i]

Commonly when valves are badly clogged the most noticible symptom is hesitation and sometimes bucking during part throttle acceleration, usually around say 2-4K rpm.

Like others have said though, there is probably a bit of build up at that mileage... it’s sort of one of those things that slowly happens over time, so you may not notice the deffierence until it’s fixed and suddenly you gain HP.

[ShocknAwe]

Originally Posted by davemohan

I want to say thanks for the replies!

@ShocknAwe - This is pretty much what I was thinking, looking at the intake tracts they are certainly not sparkling clean, but it is not what I would consider "build-up" that is interfering with flow. At this point I'm pretty much seeing the walnut blasting the same way you describe catch cans. And "blasting" powdered medium into your intake tracts, no matter how well you're cleaning up after, is not to be taken lightly. As to the valves and seats, considering direct injection, probably overdue for cleaning. If you are in Charleston, SC is there anyone you could recommend? I'm in the Fort Mill area, but I'm used to traveling for quality service.

There isn't a shop in Charleston that seems to be willing to do it. I've been looking as it's been ~50k since my last valve cleaning and my car needs it.

If you find someone ANYWHERE in SC that can do it. PM me.

[davemohan]

I'll be looking after the 1st, will let you know what I come up with.

[blue135]

Shock;

Good place in Concord near Charlotte Motor Speedway. If interested in going that far let me know and I will dig out name and number.

[fast1eddy]

This is what my intake valves looked like at around 100k miles.


Not sure if it had ever been done before but it was very nasty in there. I'd say the intakes were restricted by about 30%. The car idled and accelerated way smoother after the blasting. 100% worth doing.

[ShocknAwe]

Originally Posted by blue135

Shock;

Good place in Concord near Charlotte Motor Speedway. If interested in going that far let me know and I will dig out name and number.

PM me name number and their price if you would. Have family in Greenville. Not a bad drive from there.

[QU1CK]

Im in the Steel Creek area, glad to see another local on the forums!
There's a shop in Monroe, NC called EuroMpire that I'll be using next month (129k currently and I assume it's never been cleaned).

[DarthFader]

When my N54 e92 needed walnut blasting it was bogging down on hard acceleration, felt like misfiring. The car was CPO at the time so dealer changed plugs, coils, injectors, etc and nothing helped. Finally they walnut blasted and she purred like a kitten again. I only paid the $50 deductible!

Car had ~70k miles at the time.