SIDI carbon cleaning thoughts??

[greenacc]

How much of an issue is this? Recently bought an evoke with about 120,000 km on it and curious if the valves are likely to be full of carbon and need a clean. If it needs cleaning what is the best way to fix it?
Do I need to lift the intake and spray intake cleaner straight on the valves?
There is very little talk on the forum about this. Does that mean it's not an issue or just one of those issues we don't talk about, like fight club
Next question, are people using injector cleaner on their SIDI motors and getting any benefit?

 

[Ron Burgundy]

Does the car run fine ? If yes, leave it alone

 

[someguy360]

Does the car run fine ? If yes, leave it alone

This, having carbon cleaned several Diesels over the years, if it's running fine don't touch it.

Can of worms etc.

 

[greenacc]

Does the car run fine ? If yes, leave it alone

Runs like a 2 litre Camry. It's hard to say if that is how badly Holden built the 3 litre engine or if there's an issue that needs sorting.
For some reason carbon cleaning was a hot topic ten years ago then it went quiet. I just don't know why.

 

[rambunctious]

I didn't think carbon was a problem with unleaded fuel but if you wish, the simplest way is connect up an oil injector/drip feed kit and use water instead of oil.
It will steam clean the head and valves.

 

[Skylarking]

I though some factory service schedules included injecting a valve cleaning fluid via the intake of direct injected engines, specifically to combat such crud building up on the back of the valves.

From what I’ve heard, Subaru mandates such intake cleaning as part of their scheduled service but I’ve got no idea what Holden mandates for their direct injected engines.

Supposedly Kia released a service bulletins that recommends such intake cleaning isn’t performed on their CDI vehicles.

Who knows the truth these days since car makes aren’t interested in long lived vehicles, only in you flipping for a new vehicle every few years… and in you paying for subscription services (for seat warmers … has BMW really learnt it’s lesson?)

 

[greenacc]

I didn't think carbon was a problem with unleaded fuel but if you wish, the simplest way is connect up an oil injector/drip feed kit and use water instead of oil.
It will steam clean the head and valves.

It's not an issue with fuel.
Direct injection works different to conventional multi point efi port injection. The fuel stream from the injectors in conventional efi is behind the valves and so cleans the valves on the way past. But, direct injection fires straight into the cylinder so **** can build a up on the back of the valves in certain driving conditions and blocks the airflow like cholesterol in a heart attack.
Sounds like I'm just going to have to lift the manifold off and have a peek inside at some stage.
https://www.google.com/search?clien...AB&biw=360&bih=592&dpr=2#imgrc=mLIuMfbpuxX6fM

 

[3rspecB]

Every service for all my vehicles including the LS3 Redline, I sprqy the Subaru upper engine cleaner a day or so before oil change and I put in a bottle of Nulon Pro strength injector cleaner in the next full tank. Never had any issues when I had my Subaru's and with my current fleet of vehicles. I had 2 boxes of the upper engine cleaner left over from my Subaru's days.

Each to their own I guess.

 

[vr304]

Wouldn’t hurt to spray some upper engine cleaner in the intake with the engine running

 

[Skylarking]

It's not an issue with fuel.
Direct injection works different to conventional multi point efi port injection. The fuel stream from the injectors in conventional efi is behind the valves and so cleans the valves on the way past. But, direct injection fires straight into the cylinder so **** can build a up on the back of the valves in certain driving conditions and blocks the airflow like cholesterol in a heart attack.
Sounds like I'm just going to have to lift the manifold off and have a peek inside at some stage.
https://www.google.com/search?clien...AB&biw=360&bih=592&dpr=2#imgrc=mLIuMfbpuxX6fM

Interestingly, some manufacturers consider heavy carbon buildup can only be effectively removed using media blasting.

Honda’s take on the matter is rather interesting in that they perform a ECU update to ensure the conditions that cause the buildup are minimised and they also use media blasting as the removal process rather than fluid injection… The Honda TSB below:

https://static.nhtsa.gov/odi/tsbs/2022/MC-10215233-0001.pdf

GM’s take isn’t clearly defined with reference to specific engines, etc but they do have a poorly written TSB on the issue of carbon buildup. The GM TSB below:

https://static.nhtsa.gov/odi/tsbs/2020/MC-10176607-9999.pdf

I still haven’t looked at the Holden service scheduled but then again that weak doc from Holden doesn’t even reference changing the magic unicorn skinned pixy dust covered fuel filters…