Thread: Engine Carbon Clean- DIY, or snake oil?

Steam would work, but I'd be worried about bits of rock hard carbon bouncing around the chamber and through the turbine?

I used Redline RL2 diesel additive at a maintenance dose for years in the old Tdi and the pistons were absolutely spotless at 330,000km when the head came off.

I actually used it for pump lubrication but Cooma Diesel reckoned the pump was totally shagged when they reco'd it for the new owner?
Funnily enough it was running fine, was going better than ever with great economy, just had a a throttle spindle leak?

I'll dig a photo up of the pistons, all the numbers are easily read on the crowns but it just may not be tonight.

sounds like misting a 2.25p to decoke it...

something thats worked since before the 70s will probably still work now... unless the laws of physics have changed.

the issue is as identified...

what used to do really well in the old cars might not be so fantastic for a new car... I'd hate to be the one to have to tell the new owner, well this chunk of carbon came out the intake into the runner, stuck in the valve didnt let it close properly and now because valve met piston you need a new donk.

Snake oil - if you’ve ever tried to remove that crud in the intake of a modern diesel you’ll know a quick mist of something won’t touch it. It’s like concrete and is bloody hard to shift. Save your money.

I understand there might be risks, but they'd have to be calculated risks given that there is a business devoted to it (he'd not be doing business long if 5% of every job resulted in a catastrophic failure).
As for me paying to have it done, I'm not that daft- I was a skeptic from the start, hence asking the brains trust. If I were to give it a crack, I have all the equipment at home to make it happen, for little to no cost.

One of the reasons for me asking was that when I was young, a relative and I were getting an old Holden running. We removed the air filter and splashed a small amount of water down the carb barrels with some steady half throttle revs. I've also heard that it is possible to switch 2 of the spark leads around to promote a backfire, and use this as well to attempt to shock some of the deposits out of the intake. But an old holden 202 is a long way from a common rail 2.2TDCi.

As far as the puma goes, I'm sitting at approx 55,000KM at the moment, it has always been a country car, and I don't do 'mall crawling' or 'soccer mom' duties in it, so I'm not expecting huge deposits in my engine as a result of short run times on a cold engine.
I would be interested in at least a partial tear-own of the choke points and seeing where I sit. Or borescope it if I can get there. So open to ideas as to where to look first.

I use a range of engine/fuel treatments incl RL-2 suggested by Rick.

One of them has been Revive which is a water based induction cleaner. My mechanic recommended it and so I got him to do a treatment on my RRV 3.6 tdv8 with about 250,000km at that time. The tdv8 wasn’t running rough, but after the treatment was noticeably quieter, smoother and a little more responsive. I had another treatment done about 20,000km later but no change.

I also had him do the treatment to our 2008 Pug 407 2.0 diesel with about 80,000km at the time. We previously had a EGR plate put in to fix a engine surging issue. I had him take out the plate for the treatment. The car didn’t feel any different but ran well without the plate. I have since put the plate back in.

So that’s my experience with induction cleaners. Here’s a YouTube link to a review (info-mercial).

YouTube

Am I right in thinking some additive cleaners just basically add ethanol to the fuel to dissolve the crud?

Back in the day, and Blknight Dave will remember this one, we'd use brake fluid to do an in situ de-coke.
The bloke who told me was a RAEME mechanic, and a RAAFie tech confirmed they used to do the same (and use Bon-Ami tipped down the bore to bed in rings in big Oshkosh gensets!)

It makes me shudder now, but it's what we did.

With the brake fluid on little B&S's you'd get chunks of carbon flying out of the muffler!

Engine life was considerable shorter in those days.....

Then there was the old method method of de-coking a 2 stroke motorbike exhaust with an oxy set.

1. Remove complete system

2. 'Warm' the header pipe up with oxy - acet down the throat

3. Turn the acetylene off but keep the oxygen going till clean right through

I reckon they would get pretty hot.

DL