Upper cylinder cleaners

Armidillo

Armidillo

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When I got my first Xantia in 2006, it seemed to be popular to de-coke piston tops etc. by pouring a teaspoon or two of brake fluid through the spark plug hole, and leaving it overnight to work it's magic before starting the car and admiring the clouds of smoke. This of course was supposed to loosen up carbon deposits and allow them to be swept out with the exhaust. I confess I did try it at the time - can't say that I was aware of any massive performance improvement, but it didn't appear to do any harm (apart from smoke affected washing).

Is this still an approved technique? Or has it been relegated, along with tin canisters etc., to the dustbin of history? Are there downsides (could it increase bore wear, gum up exhaust valves, block the catalytic converter etc)?

I am also intending to feed the engine a can of LiquiMoly Petrol Engine Intake Decarb. I am hoping this will clean up the air intake tract, but does it make the brake fluid redundant?

The engine I am thinking of trying it on is a 19-year old ES9J4, that has traveled c. 170,000km.

Cheers

Alec
 
I thought that sort of thing went out in the 1950s. I'll be interested to see what people say though.
 
Probably end up losing all your compression if you have any left that is :whistle:
 
Compression is good - 180 +- 5 psi on all 6.

Please excuse my cracked 'glass':
attachment.php


Cheers

Alec

Compression gauge.jpg
 
Armidillo said:
When I got my first Xantia in 2006, it seemed to be popular to de-coke piston tops etc. by pouring a teaspoon or two of brake fluid through the spark plug hole, and leaving it overnight to work it's magic before starting the car and admiring the clouds of smoke. This of course was supposed to loosen up carbon deposits and allow them to be swept out with the exhaust. I confess I did try it at the time - can't say that I was aware of any massive performance improvement, but it didn't appear to do any harm (apart from smoke affected washing).

Is this still an approved technique? Or has it been relegated, along with tin canisters etc., to the dustbin of history? Are there downsides (could it increase bore wear, gum up exhaust valves, block the catalytic converter etc)?

I am also intending to feed the engine a can of LiquiMoly Petrol Engine Intake Decarb. I am hoping this will clean up the air intake tract, but does it make the brake fluid redundant?

The engine I am thinking of trying it on is a 19-year old ES9J4, that has traveled c. 170,000km.

Cheers

Alec
Click to expand...

You obviously haven't been using enough "REDEX" Upper Cylinder Lubricant, so I'd recommend a treatment of good old "Bristol Self De-Coke"!!
 
As Peter has alluded to, Subaru have a product that can be sprayed down a vacuum line whilst the car is running. I used this cleaner on a XU10J2 many years ago that had a massive carbon build up behind the inlet valves. I removed the injectors and cut down the sides of a toothbrush to fit in the injector hole. I sprayed the foam down the hole of a closed valve and scrubbed the back of the valve with the toothbrush. The original build up was about 6mm thick, and after 20 mins work all were clean.

I ran the motor producing a large cloud of smoke for 5 mins, and all was well. The car did pick up some power after cleaning.
 
Double post. Posting on a phone sometimes doesn’t work so well.
 
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Hmmm - no harmful chemicals, allows easier breathing etc. - sounds like I should try it for my asthma!

Cheers

Alec
 
Here is the result of putting a can of Subaru cleaner through an XU10J4 which had done approx. 200 000Km. It was a lot worse than that before I had time to get the phone out.
 

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Very impressive - looks similar to the results of the brake fluid treatment! At first I thought I could see soot particles in the smoke, but they turned out to be spots on my screen!
 
Carbon build up on a 12 month old Clio 1.2? Must have been used for short trips exclusively. If that's the case we better look out for Covid short trip DI engined cars a bit down the track?
 
No, it's just another service department add-on sales pitch.

Subaru and Nulon make solvents that help, and perhaps postpone the big port clean time, but it comes eventually.
 
Had a company Sigma. Dog of a car. Hated it. It hated me too. Tried to kill me several times.
At the grand mileage of around 50,000 Km it started to run on when hot.
You could turn the engine off, lock it and go away. Come back to it 5 minutes later and it would still
be banging and sputtering, dieseling backwards and forwards. Impressive!
So I thought I would try to kill it when I got home and it was hot and up to its antics.
Took off the air cleaner, held the revs at about 3000 RPM and dribbled the water hose into the carb.
It didn't like it, so more revs and more water. Totally environmental of course.
The pesky thing behaved itself after that. Job done.
It went so well that after 100,000 K's I just gave up and quit that job.
Evil always wins...
 
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