[bikertillidie]

Originally Posted by scorpian

I would say the EGR is the reason for the extreme carbon soot buildup. One of the reason i did a remap was to close the EGR and also post that i removed the intake manifold and it was clogged by over 70percent at 88k kms.

My advise would be to get a soft remap done and close the egr and get the intake manifold and head cleaned once so that you will not face this issue again.

Thanks Scorpian. This could possibly be the foremost contributor to carbon deposition.

Has anyone used a blanking plate to isolate the EGR assembly completely?
That would be a much easier option as the assembly is held in place by only two M6 bolts.

The intake manifold on Ford Tdci diesels can be easily accessed by removing the valve train cover. I am seriously contemplating use of carb/choke sprays/scraping off deposits using a screwdriver to clean off the buildup..

Attaching a picture of cylinder head for reference. The four largish round openings at the top lead to the intake valves

[Aroy]

Originally Posted by bikertillidie

Just came across this thread. Makes for a very interesting read.

Modern direct injection engines are bound to end up with a fair amount of soot/carbon deposits on intake valves due to their very design.

What's the best best way to decarbonise such engines?

Introduction of cleaning agents/fuel additives does not really help here as fuel is sprayed directly into the combustion chamber..

Any thoughts?

In most modern engine carbon deposits are found in the intake side. Exhaust side deposits are burnt once the engine reaches optimum temperature and is run for at least 30km+. The so called Italian-Tuneup is just running the vehicle at moderate to high speed (on open highways) for at least 100km, ideally 200. That will get rid of msot of the carbon deposits in the exhaust side.

For intake side, there is no magic solution. Just get the intake manifold cleaned every now and then.