DISI Engines with carbon buildup

[Scaredycrow]

During my travels on the internet I came across this link.

It shows the carbon buildup inside a VW DI engine, which has been well discussed on various other car forums around the globe. Suffice to say this issue is not limited to MZR engines, or for that matter "cheap" engines. Audi, Porsche, BMW, and Mercedes are all known to suffer the side effect.

Given that I've tried a de-carbonising on my car previously with limited apparent effect, I thought I'd have a look around at the other options. I found this: Seafoam - Deep Creep

This product is sprayed into the intake, rather than the vaccum hose applications of most other de-carbonising agents. Makes me think that it would likely be much more effective as it would be passing the tops of the vavles etc.

Any thoughts?

Now just need to find somewhere that sells it...

[Jmac]

Dont subaru use this on their cars? It definitely sounds familiar...

[TUFMPS]

Hmm ask Frankie3mps.. he works @ subaru i think..

[Sunder]

I used to use Subaru upper engine cleaner every service... Been a bit slack and only done it every second service.

If you think the photos on the other thread are bad, years ago, I bought a 14 year old Pulsar with 280,000km on the clock as a donor car. Bear in mind this was NOT a turbo car and so didn't have any issues with blow-back etc. In places, I could use a screwdriver to take 1.5-2.0mm off the intake runners, and easily 2-3mm off the crown of the pistons.

This would have severely impacted compression, but the car still ran... Not well, but it ran!

I'm at 98,000km at the moment, I think at 100,000 I will get two cans, and when I'm changing the spark plugs, put a small layer down each cylinder (if you're gonna take this as advice, make sure it is a very thin layer - too much and you will hydrolock) and put another can straight into the plenum through the TB, not a vacuum hose. Leaving it to soak for a few hours should get rid of most the carbon.

[Scaredycrow]

I used to use Subaru upper engine cleaner every service... Been a bit slack and only done it every second service.

If you think the photos on the other thread are bad, years ago, I bought a 14 year old Pulsar with 280,000km on the clock as a donor car. Bear in mind this was NOT a turbo car and so didn't have any issues with blow-back etc. In places, I could use a screwdriver to take 1.5-2.0mm off the intake runners, and easily 2-3mm off the crown of the pistons.

This would have severely impacted compression, but the car still ran... Not well, but it ran!

I'm at 98,000km at the moment, I think at 100,000 I will get two cans, and when I'm changing the spark plugs, put a small layer down each cylinder (if you're gonna take this as advice, make sure it is a very thin layer - too much and you will hydrolock) and put another can straight into the plenum through the TB, not a vacuum hose. Leaving it to soak for a few hours should get rid of most the carbon.

Lol 280,000 is rather a lot. Those pictures are replicated on cars with as few as 13,000 miles. THATS the scary part.

As for the UEC, its great and everything, but unless it goes in the air intake (I don't know, does it?) its not going to clean those valves.

If you've done 100,000 k's (or judging by some of those pics, as few as 20,000) you'd be better off removing the head and having it ultrasonically cleaned. Otherwise you run the risk of "chucks" of the carbon deposits going through the motor and damaging, pistons, valves, turbo impella, everything important lol. Then you can, as you say, put the cleaner through the intake every service to keep on top of it.

I'd been keen to hear if Subaru or any other manufacturer have a product equivalent to the product that will safely go through the intake on a turbo.

---------- Post added at 04:17 PM ---------- Previous post was at 04:10 PM ----------

Seems like this question might have been answered before!

Upper Engine Cleaner - Subaru

To answer my own question... Yes the UEC does go into the air intake, but its advised to do it AFTER the turbo if possible. Best results would be after the intercooler, straight into the IM.

[Sunder]

Lol 280,000 is rather a lot. Those pictures are replicated on cars with as few as 13,000 miles. THATS the scary part.

As for the UEC, its great and everything, but unless it goes in the air intake (I don't know, does it?) its not going to clean those valves.

To answer my own question... Yes the UEC does go into the air intake, but its advised to do it AFTER the turbo if possible. Best results would be after the intercooler, straight into the IM.

From those photos, I'd be happy to use UEC. The nature of the solvent isn't that it forces it to break off and enter the engine in chunks - it actually dissolves and becomes part of a solution which is then highly volatile and burned off.

If it was 1-2mm thick on the other hand, yeah, I'd be stripping down the engine and cleaning it in a hot tank and reassembling - or just buying a new engine.

UEC goes into the throttle body through a vacuum hose if you follow the manufacturer's recommendation. It's designed for boxer engines which get more carbon build up. It's good stuff. When I first came across it, it was because I was having some pinging issues on a S2000. First time I ran it, I thought I'd ruined my engine - the smoke coming out the back was incredible. You couldn't see a metre past the back of the car. I ran it every service after that, and almost no smoke comes out.

[Scaredycrow]

I get that its designed to dissolve the gunk. Just concerned that on a higher K engine the gunk might be a lot thinker. But hey it's your car mate, I'm certaily not going to tell you what you can or cannot do with it

I've got hold of a similar product this afternoon. Its made by Wurth link

Going to give it a try over the weekend. My car has ~46,000k's on it so fingers crossed all of the crap gets dissolved

[Doc]

tunehouse can do this procedure as part of the service... just another reason to go to them

[Scaredycrow]

Did it today and... Idle is MUCH smoother now. Didn't entirely pick up on how rough it had become until it was better lol.

Ended up using a Wurth product. Couldn't get the Subaru UEC as they're all closed on weekends! Pretty happy with it though!

[Doug_MPS6]

I bet half the problem, if indeed there is an endemic one, is that the majority of these turbo cars are spending their lives in urban areas and short runs to and from work. Lots of over-fuelling due to intermittent traffic light boosted sprints and deceleration, very few long steady or sustained high speed runs, sooting cylinders, plugs and cats, acid and moisture buildup not being burned off, lots of crud everywhere, even down the exhausts. I never saw a high-mileage, open-road engine cak itself up or rust out its pipes like some of these seem to be doing.

Even if you live in Ballarat and run to Melbourne, or say from Parramatta to Sydney, every day, the issue isn't really resolved in those commuter traffic quagmires, where in 6th you are still only at 2500-3000rpm at best, and then only in short bursts. Where I live, it is only 8km into Perth and given the funereal pace of traffic here, thanks to those who have been beaten into submissive compliance by the speed nannies and who choose to clog up our urban arteries with their own version of automotive cholesterol, I'm lucky to see 2500 rpm in 5th, far less get into 6th. Result?.....unhappy engines. 100,000kms is nothing. There's no reason these motors shouldn't be seeing 200-250,000 before major attention being required, perhaps even more. I can't talk - I've only got 45,000km on mine in 4.5 years! :-(

I just went on a weekend sporting activity involving mostly a reasonably fast country run over 120kms, apart from a bit of the alleged "freeway" south, at a sustained higher speed than normal. Not far, but enough to notice a marked improvement in my engine's demeanour by the time I got back home.

It's a good case for more weekend club runs.......