Fuel adatives....

[SR71]

Before you spend your money;

1) Maybe we ought to get some info from Mitsubishi as to what kind of build-up the spray is capable of moving?

2) Maybe SilverRS4 can comment whether in his experience, bearing in mind the effort expended to clear up his inlet, a spray will do the job?

Sounds like MRC might be have a solution (with additional power an added benefit!) but I'd want to see the effects before someone goes tapping holes in my inlet...

[Andyuk911]

As long as you don't spray the MAF .. I am ok with this ..

[pippyrips]

I think the sprays will be more preventative than cure, no matter what the PR says.

The best way has to be to take the manifold off, clean properly then use spray etc to avoid needing to do so again.

(The injector was just an idea, not a recommendation)

[pippyrips]

As long as you don't spray the MAF .. I am ok with this ..

Useful pics to have on tap Andy

How would/could you avoid it - spray to the side and hope for the best?

[silverRS4]

Spray a chemical in the airbox and clean the intake valves? I know there are some good chemists out there, but I'd have to see that. The buildup is like half-dried epoxy glue. Even after soaking in a solvent, you have to have the right tools and finesse to get it to come off - Caldy can attest to that. And then what? Once you dislodge the gummy chunks, you certainly don't want them entering the cylinder so they can come in contact with the injector tips or spark plugs. But if its used on Mitsu's effectively, maybe there is something to it. I don't know.

[sonny]

Will the build up effect performance? Will Redex/additives work...prob not as mention its a direct injection, i.e. spray is below the valves not above them...so chances are, Audi are aware of this! Is the build up the excess oil we see be used on such monthly basis!....to be honest I would not get a flap on about it, unless we actually see proof that is has effect performance!

If it was the case, then surely it would be a head off job as no spray will be able to remove it 100% Just my humble opinion!

[caldy]

I've had neat Redex soaking in the head for 3 days now and apart from it turning black, it has done little if anything to soften the deposits. Agitation with a wooden spatula barely removes the surface contamination and has no effect on the harder, base deposits. I'm going to try a solvent next and hope that works more effectively. The cylinders with the open valves will obviously be dosed with the neat solvent but this cannot be avoided.

[Jezzer]

Andy - Dave your cars I believe have now done 20k+ miles, have you noticed any downturn in performance in the last year. Mine has only done 11k and it seems to be getting better as the miles are put on. Are there any British cars that have been inspected around the inlet valves? There is a seller on here (APM) with over 80k miles on his RS4. I have PM'd him to ask how he has judged the performance of his car in the last year and to post his findings.

[tartan_rob]

My car has 50k on it. I maybe tempted to take the manifold off for a look. I can do most jobs on the car myself, any idea how long it takes and what tools are required?

R

[PetrolDave]

Andy - Dave your cars I believe have now done 20k+ miles, have you noticed any downturn in performance in the last year.

Not that I can tell - still goes quick enough to excite the TC and for the wife to adopt the "brace position"!

I'm thinking of giving the Wynn's stuff a try - if it seems to help on Mitsubishi's GDI engines then there has to be something in it, maybe more as an onging preventative measure than to remove existing deposits though.

[caldy]

All you need are a selection of Torx bits and preferably a 1/4" drive socket set. An angled screwdriver set is advantageous as is a spring clip compressor. You will probably need to break a couple of 'one use only' clips. It's very straightforward to undo but I cannot yet comment on putting it back together - that's for this weekend!
Took us about 2 hours to remove. It is very fiddly with severe access problems at the back of the manifold, especially behind the filter housing, but with the right tools it can be done. It is obvious that the engine is assembled outside the car as all the clips seem to be facing the wrong way for easy access. Be prepared for lots of swearing.............
Good luck.

[sonny]

Im on 24K mileage and I run a 374 bhp on Surry Rolling Road last month! overall, I have not noticed a effect in performance wise!

[caldy]

This is what awaits underneath!

http://i271.photobucket.com/albums/jj12 ... G_2210.jpg

[pippyrips]

Are there any British cars that have been inspected around the inlet valves?

Yes - i know MRC have opened up an engine and found build up around the valves. Not sure of quantity or mileage (engine came from a breakers) but i will be talking to them later so will ask.

I don't think the issue is too related to the type of petrol you use, it’s down to oil vapour in the inlet tract.

I posted this link in another thread but is relevant here:


http://www.bobistheoilguy.com/forums/ub ... er=1171236

For those interested the Wynn's DIP3 is £15 for the two and available at your local MotorFactors.

I also will give it ago once all my valves etc have been cleaned up properly.

[caldy]

As far as spraying direct into the inlet, it's far easier than you think. Just to the right of the throttle body, on the inlet manifold casting, there is a blanking plug that is simply pushed on to a pipe. This leads directly into the manifold opening and is downstream of the MAF.