n54 Intake valve cleaning

Nick9one1 · Post by **Nick9one1** » Sun Nov 04, 2018 7:58 pm

Has anyone else on here had the intakes cleaned/walnut blasted? Seems like a pretty common thing for the N54.

I did mine today... no walnuts, but with carb cleaner, small brushes, rags etc.

Before

: IMG_20181104_142901.jpg (72.2 KiB) Viewed 1821 times

After

: IMG_20181104_172002.jpg (97.43 KiB) Viewed 1821 times

Not quite as clean as when walnut blasted but far better than they were

Player 1 · Post by **Player 1** » Sun Nov 04, 2018 8:20 pm

Wow, that's worked really well! Has it made any difference to the way the engine runs?

I think I'll do something similar next year as its inevitable with direct injection.

Nick9one1 · Post by **Nick9one1** » Sun Nov 04, 2018 8:24 pm

I was surprised how well they came up.

It definitely idles silky smooth now, it was ever so slightly lumpy prior to cleaning.
Not noticed a massive difference when driving but I've only taken it round the block.

I'll probably reset the adaptions in ista and see if that makes a difference too.

I've got an oil catch can to fit at some point - Hopefully it will reduce the buildup.

ph001 · Post by **ph001** » Sun Nov 04, 2018 11:44 pm

Nice pics. I’ve never clearly understood where all the carbon crap comes from on the inlet valves. Surely it’s just clean filtered air going in there, or is it becuase of the exhaust gas recirc / ccv garbage?

Nick9one1 · Post by **Nick9one1** » Mon Nov 05, 2018 12:00 am

Thanks!

I think it's because of the ccv/egr (although the n54 doest strictly have egr).

To meet emissions standards manufacturers re-burn some gasses created by the engine. Traditional engines have the injectors before the valves, so the fuel 'washes' the ports keeping them clean. As the n54 is direct injection, any oil/carbon that is sent back into the intake from ccv/egr tends to stick.

ph001 · Post by **ph001** » Mon Nov 05, 2018 11:26 am

Yeh, I understand why it's not an issue with port injection. If the source of the problem really is 100% down to crankcase ventilation systems then, you do wonder how hard it would be to disable / block the CCV operation to keep the whole intake side an awful lot cleaner.

Lazza · Post by **Lazza** » Mon Nov 05, 2018 12:10 pm

Is EGR Delete a thing on these engines? I know it's common on MX5s and often done on diesels...

R.E92 · Post by **R.E92** » Mon Nov 05, 2018 1:45 pm

I had it done at the dealer for £250 while it was in for other warranty work. It's probably due another clean soon, might see if I can get a boroscope in without having to pull the entire inlet off.

I think a lot of the buildup comes from valve overlap during cruise conditions. With tuned cars it will be less of a problem as the overlap is removed as part of the VANOS table changes.

Cees Klumper · Post by **Cees Klumper** » Sat Jun 15, 2019 11:49 pm

I will be doing this soon, just bought the car with 95K miles and previous owner never had it done and didn't know if it was done before his time. I have noticed at idle it 'skips' a bit from time to time, and I'm pretty sure this carbon build up is the cause of that. Otherwise the engine pulls like a bullet train.

Nick9one1 · Post by **Nick9one1** » Sun Jun 16, 2019 5:15 pm

Cees Klumper wrote: ↑Sat Jun 15, 2019 11:49 pm I will be doing this soon, just bought the car with 95K miles and previous owner never had it done and didn't know if it was done before his time. I have noticed at idle it 'skips' a bit from time to time, and I'm pretty sure this carbon build up is the cause of that. Otherwise the engine pulls like a bullet train.

I had the same, mine 'skipped' occasionally when at idle. The intake clean is worth doing, but I wouldn't expect it to cure this (it didn't for me).

If you've never had new injectors, I'd say they are the most likely cause. Especially when cold.

Next would be properly gapped plugs.

Jollyjoiner · Post by **Jollyjoiner** » Sun Jun 16, 2019 5:47 pm

Nick9one1 wrote: ↑Sun Jun 16, 2019 5:15 pm
Cees Klumper wrote: ↑Sat Jun 15, 2019 11:49 pm I will be doing this soon, just bought the car with 95K miles and previous owner never had it done and didn't know if it was done before his time. I have noticed at idle it 'skips' a bit from time to time, and I'm pretty sure this carbon build up is the cause of that. Otherwise the engine pulls like a bullet train.
I had the same, mine 'skipped' occasionally when at idle. The intake clean is worth doing, but I wouldn't expect it to cure this (it didn't for me).

If you've never had new injectors, I'd say they are the most likely cause. Especially when cold.

Next would be properly gapped plugs.

You say this didn't cure yours but yet when you first did it you said it was now running silky smooth ?? so did it cure it for a while then start idling lumpy again?

mcbutler · Post by **mcbutler** » Sun Jun 16, 2019 8:18 pm

How many miles on your car and is this the first time you have done this?

Nick9one1 · Post by **Nick9one1** » Sun Jun 16, 2019 8:34 pm

Yep it was the first time. I think the milage was about 90k when they were cleaned.

I plan to take the inlet off to see what they look like now at 100k.

I also added an oil catch can in the hope it would slow the build up.

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