Short of taking the head off and having the inlet valves all manually cleaned off, can anyone recommend engine treatments, which will remove the crud that builds up here in direct injection petrol engines.

Obviously the best way to get it all off, is to have the head taken off and the parts scrubbed, but this just isn't practical to do a couple of times in the cars life.

Injector cleaner etc, will help with the injectors, but now that the fuel doesn't pass the inlet ports, it's going to do nothing about the coke around there.

Thoughs appreciated, especially if you've got firsthand experience of the solution.

Ta

What was that thing on Wheeler Dealers the other day? Carbon deposits I think.

I'm sure it was, but it's only going to deal with the injectors.

I've got a BMW service doc that shows them doing the same thing, and it'll clean out the injectors and cylinders, however doesn't seem as if it'll affect the intake valves, due the injectors being in cylinder rather than in the intake path.

We used to a big problem with the mitsubishi based GDi engine's in the old s40's coking the inlet valves up and causing all sorts of issues from lack of performance to rough idle to misfires

The main problem was the EGR valve and the engine breather system into the inlet manifold and it would coke up the back of the inlet valves and the inlet tracks in the head these would coke up worse if the car only did say school runs, the reps that hammered the cars up and down motorway never really had a problem.

We tried allsorts at work from injector cleaner in tank to spraying carb cleaner etc down inlet track with engine running but nothing really works apart from taking head off and doing it properly. we now have one as a run about / dumper at work thats been to moon and back. when i got my car stolen i borrowed it for a week it was running like a bad of crap. After a week of me having it and thrashing it up and down motorway for a week it ran alot better.

As per the last post, I think an "Italian tune up" might be useful.

We used to a big problem with the mitsubishi based GDi engine's in the old s40's coking the inlet valves up and causing all sorts of issues from lack of performance to rough idle to misfires

Lad at work with a S40 and GDi engine had this.

What was that thing on Wheeler Dealers the other day? Carbon deposits I think.

That cleaned the emissions up btilliantly for a very reasonable price. £75.