How to remove carbon build-up in the Intake manifold on FSI and TDI engines

steaman

steaman

A2OC Donor
I an trying to find the best way to remove carbon build-up in the Intake manifold on FSI/TDI engines.
This seems to be a problem on all engines that inject the fuel directly in the cylinder.

It seems like the only secure way is to clean the intake manifold with:
  1. walnut shell blasting: https://www.youtube.com/watch?v=NnMhNXXawjk
  2. or with mecanical and chemical cleaning: https://www.youtube.com/watch?v=Ugh9vPz2Zd

Anyone found a simpler way to remove all carbon build-up?
 
On my TDI's I use the Oven Cleaning method. It foams and clings to all surfaces, leave for a good while, pressure hose it out and repeat until sparkling.

https://www.youtube.com/watch?annot...&feature=iv&src_vid=hrL6ZS56gkE&v=cCjO8JThVpo

This is also a good way to clean the intake side (only) of the turbo.

I get my Mr Muscle equivalent in Poundland.

In my early days of 2 stroke motorcycles in was fun to take the exhaust off, pour petrol down and set it alight to burn the carbon out.
 
I think Oven Cleaning is is excellent as described in method #2 where chemicals are used after mechanical cleaning.
 
Today I tried the laze method, Liquide Moly Pro-Line Throttle Valve Cleaner. I removed a small hose connected between the throttle valve and the intake manifold and entered the spray pipe there. As result I had to reset a few Error Codes

After the cleaning procedure I also replaced the spark plugs. The replacement was planned but they were real sooty as result of the treatment.
 
The treatment with Throttle Valve Cleaner has transformed the engine. When I bought the car in December I complained about the engines lame appearance but didn't have anything to compare with. No it has more torque on low revs but also much more to give all over the range.
The only complaint I have left is unstable revs at 2000-2300 rpm when cruising at steady speed.
I will try to clean the Trottle Valve tonight and as a next step replace the Air Mass Meter.

Big transformation from a lame engine to a inspiring and rev happy engine.
 
Started to remove the Trottle Valve for cleaning, but found this:
LMM.jpgMAP2.jpg

Isn't this clean enough, or?
 
If the throttle has been cleaned or removed you should reset the throttle. This should cure the wondering rev problem. :)
 
:) Sorry for the confusion, but the photos are without any cleaning. I never touched the Trottle Valve or the Air Mass Meter. Thats why I questioned the need to reset the Trottle Valve.
 
If you have access to VCDS then follow the Throttle Body Adaptation process.

It has obviously been cleaned recently looking at those pictures, and may not have been put through this step.

You will not do any harm by following those steps.

Cheers
Jeff
 
the throttle body generally looks good from the top and awul from the bottom.

I'd take it off and take a look underneath anyway. Replace the gasket as necessary. Mine's leaking slightly and shows up as an error message when it's over 30C outside.

- Bret
 
I took my throttle body off and cleaned it fully but I still have the same, lame performance below 3000rpm. Activities to date are: full service, plugs, filters, oil. Replaced all the coil wiring from the main loom to each coil. All earths cleaned and redone. I am now on my 4th tank of fuel with injector cleaner. Cleaned the MAF.

Watching this thread closely hoping for inspiration.
 
And you have calibrated the Trottle Valve after cleaning?
My A2 is not lame below 3000 rpm. My problem is the instability with a steady gas pedal, like the rpm oscillating e.g. 2300 rpm +/- 100 rpm.
I will continue my troubleshooting in August, after Vacation on an island with only Tractors, ATVs, Mopeds and Bikes. But we have Fiber connection. :eek:
 
steaman said:
And you have calibrated the Trottle Valve after cleaning?
My A2 is not lame below 3000 rpm. My problem is the instability with a steady gas pedal, like the rpm oscillating e.g. 2300 rpm +/- 100 rpm.
I will continue my troubleshooting in August, after Vacation on an island with only Tractors, ATVs, Mopeds and Bikes. But we have Fiber connection. :eek:
Click to expand...

I did the adaptation thing when I replaced mine with a new one, I don't think you have to do it if you just spray the cleaner without removing the throttle.

It's the flap thing and set position, I see no reason to do the adaptation when you open the flap by pushing the throttle pedal and not manipulating with the flap any other way while spraying the cleaner.
 
The "adaption thing" needs a Vagcom? I get minor idle flutter, but we are only talking a few revs up and down on idle. Between below 3000rpm with the pedal stationary I get a slight surging in power, but thought that and the low power below 3000rpm were linked. I bought a cheap endoscope so I could look at the top of the pistons and see what the carbon build up was like. There is some there but its not terrible.

For info, I tried the water thing on my Vauxhall corsa and it worked fantastically. I will be trying that next on the A2. (well after I have done suspension stuff)
 
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