DIY How To Walnut Blast/Carbon Clean N54 Intake Valves

[suspenceful]

I finally set aside some time to give my 335i the walnut blast it deserved at 140k miles. I want to share my process/results.

Here are the supplies I used:

• Fine Grade Walnut Shells
• Intake Valve Cleaner
• Intake Manifold Gaskets (6)
• Abrasive Blaster Kit
• Vacuum Adapter & Blasting Wand
• Brass Adapter Fitting
• Remote Starter Switch
• Pick Set
• 8mm, 10mm, 11mm, T20, T25 & Hex Sockets
• Pistol Grip Blow Gun
• Shop Towels
• Vacuum
• Air Compressor

Here are the steps I took to get to the valves...

Step 1: https://bit.ly/2JvZ98O
Step 2: https://bit.ly/2Yn6rQr
Step 3: https://bit.ly/309uSCo
Step 4: https://bit.ly/309komL

Let's get started...

Well, I think I figured out why the car couldn't eclipse 13's in the 1/4 mile! I couldn't believe what I found after removing the intake manifold!

After loosening up some of the carbon with a pick...

Then after one pass of walnut blasting...
(see video at the bottom for a detailed explanation of how to do this part)

Lots of walnuts and manual scrubbing later...

I even cleaned up the intake manifold ports because those were caked with carbon as well. You can see the cleaned port on the left and the dirty port on the right.

It was a lot of work, but totally necessary. If you want to watch my whole process with more of a DIY/How-To style, check out my YouTube video. It also has some more information and a drive at the end showing the power increase/restoration.

I hope this helps other N54 enthusiasts!

 

[fmorelli]

Nice post. Well done. For those that are running content on Youtube, this is a good example of how to make a useful forum post which includes the Youtube post. Man ... that thing was seriously caked!

Filippo

 

[doublespaces]

Nice post. Well done. For those that are running content on Youtube, this is a good example of how to make a useful forum post which includes the Youtube post. Man ... that thing was seriously caked!

Filippo

Jake is probably the most thoughtful N54 Youtuber.

 

[Bigfwop]

Jake definitely provides to the community!
Great timing given I’m gathering all the equipment to do this myself atm lol

 

[Jeffman]

I have never ever seen intake ports that caked up. Holy cow!
(First time in 140k miles, Jake?)

 

[fmorelli]

So did you plug the low side of the PCV system and externalize it?

Filippo

 

[suspenceful]

Nice post. Well done. For those that are running content on Youtube, this is a good example of how to make a useful forum post which includes the Youtube post. Man ... that thing was seriously caked!

Thanks for the props!

Jake is probably the most thoughtful N54 Youtuber.

Aw, shucks. I try!

Jake definitely provides to the community!
Great timing given I’m gathering all the equipment to do this myself atm lol

Loves of love from everyone here, thank you!

I have never ever seen intake ports that caked up. Holy cow!
(First time in 140k miles, Jake?)

Yes, 140k miles and first time it was ever done on this car. I knew they'd be bad, but I didn't think they'd be this bad!

So did you plug the low side of the PCV system and externalize it?

No, I put it back together as-is for now. I think I'm going to install one of the new BMS low-side catch cans. So I'd be running a dual setup.

 

[typedRew]

Those look about the same as mine that were done at 146k miles, well done.

I picked up so much power when I did that it started to misfire from the new airflow.

 

[suspenceful]

Those look about the same as mine that were done at 146k miles, well done.

I picked up so much power when I did that it started to misfire from the new airflow.

Wow, that's crazy! What did you do to fix the misfire issue?

I just took it out to compare the before/after performance results and shaved a half second off my 0-60 time using my Dragy device.

 

[twinturbos]

Thanks for the props!



Aw, shucks. I try!



Loves of love from everyone here, thank you!



Yes, 140k miles and first time it was ever done on this car. I knew they'd be bad, but I didn't think they'd be this bad!



No, I put it back together as-is for now. I think I'm going to install one of the new BMS low-side catch cans. So I'd be running a dual setup.

Is that out yet ?

 

[suspenceful]

Is that out yet ?

It's in the works, first 10 kits were sold!

https://www.n54tech.com/forums/showthread.php?t=57610

 

[fmorelli]

I just took it out to compare the before/after performance results and shaved a half second off my 0-60 time using my Dragy device.

My car was not that bad @ 32k miles (and nothing like yours) and I can tell a significant difference in smoothness all around - as if my car was retuned. I need to pull a couple WOT logs and see if anything is evident. I blocked my PCV feeds and switched to N20 plugs from the 97550s (with same gap) so I can't really claim the walnut blast but I'm convinced these shitty intake runners are wreaking havoc.

Filippo

 

[1and1]

Great timing- I've got all this stuff sitting on the shelf waiting for me to get off my lazy butt and do the work... Nice to see the process before diving into it myself on this engine. I've done a few valve cleanings of the Mazda flavor- pair of Speed6's and a Speed3, but doing my 1er will be my first N54. Same but totally different don't ya know...

Oh, and surprised nobody has mentioned it yet, but index 12, not 11... lolz

 

[Jeffman]

Mine have been walnuted three times now, the last two times I did it myself with the BavAuto kit. Engine definitely runs smoother after each time. Cleaning inlet #6 is a PITA, at least on an E90, as it’s really tough to get the blaster wand directed to front valve because the engine sits so close to the firewall. Be patient and check carefully that each valve is clean and you’ll be a happy camper.

#6 BEFORE after 12K miles only BMS High Catch Can, ports not plugged:

#6 AFTER Walnut blasting:

 

[fmorelli]

I really want to see port photos of someone with significant mileage on a plugged low-side and external PCV.

Filippo

 

[suspenceful]

Great timing- I've got all this stuff sitting on the shelf waiting for me to get off my lazy butt and do the work... Nice to see the process before diving into it myself on this engine. I've done a few valve cleanings of the Mazda flavor- pair of Speed6's and a Speed3, but doing my 1er will be my first N54. Same but totally different don't ya know...

Oh, and surprised nobody has mentioned it yet, but index 12, not 11... lolz

You'll be fine, just do it!

And yeah, people on YouTube commented about that. I must've misspoke because obviously I know the most recent index is 12. Doh!

Mine have been walnuted three times now, the last two times I did it myself with the BavAuto kit. Engine definitely runs smoother after each time. Cleaning inlet #6 is a PITA, at least on an E90, as it’s really tough to get the blaster wand directed to front valve because the engine sits so close to the firewall. Be patient and check carefully that each valve is clean and you’ll be a happy camper.

Nice! Looks great!

And yeah, cylinder 6 is kind of a pain. I removed the strut tower bar that connects in the middle to make life a little easier.

 

[typedRew]

Wow, that's crazy! What did you do to fix the misfire issue?

I just took it out to compare the before/after performance results and shaved a half second off my 0-60 time using my Dragy device.

The plugs were just well overdue, very worn. I did this right when I bought the car and im assuming with gunked up valves there wasnt enough air flow to blow out spark.

After I did the blast the plugs were stumbling low rpm, fresh oem plugs and havent had an issue since.

 

[Koolsilver]

I really want to see port photos of someone with significant mileage on a plugged low-side and external PCV.

Filippo

I have about 20k miles on my plugged low side with external PCV and checked how they were looking when I did my HPFP. I was a bit disappointed and they looked a little better than Jeffman’s before picture up above. They were definitely at the point that I felt like I should walnut blast again in the near future but I wasn’t up to doing it at the time.

Edit:
I should note that my OCC always does have a lot of oil in it that would be in the intake instead so it is working nicely in that way. I am also on stock turbos that have taken quite a beating and are leaking oil to some extent which I’m sure is adding to my intake valve buildup. Overall I can’t be disappointed with the results as it surely is helping but still not enough. Although it would be nice to see the results from someone with healthy turbos.

 

[Sam1245]

I have wait till 80,000 miles before cleaning the N54 intake valve and trust me it was a mess.
But I didn't know a bit about cleaning or any of the work, so I contacted my nearby auto shop, and the price they quoted me blew up my head. Then I decided to do it myself, I scrap through the whole internet google, Youtube, forums etc. Then after getting decent understanding I get across a website which slved my whole problem, it was the most detailed step by step process I've ever found. Here's the link:- https://www.automotorx.com/n54-intake-valve-cleaning/
I hope you guys can also benefit from it.