Decarbonising a diesel engine motor

[Irri_Tant]

Tried the water spray method yesterday. Sprayed water in at the EGR valve. Hope that's 'B' in the picture as that's were I sprayed in the water. Engine was at normal running temp. Got plenty of steam vapour out of the exhaust.
Didn't get the revs up though as on my own Just run at tick over circa 800 rpm. Engine didn't stall.
Put hoses back together and gave it boot on the drive and a load of soot on the floor.

Went for a drive and feels as though I have no boost as the motor doesn't respond as it did. What could be wrong?

2002passatTDI.jpg

[Eshrules]

You've sprayed water into the EGR valve to decarbonise your engine?

I thought this was dismissed as a nonsense method before on here - what was wrong with the car/engine before you did this?

[Irri_Tant]

You've sprayed water into the EGR valve to decarbonise your engine?

Yes

what was wrong with the car/engine before you did this?

Nothing I guess. Just seemed like a good idea at the time. Done 82K and doesn't get run on long distances at the moment or in the near future. Usually 12 mile round trip to work and back

I thought this was dismissed as a nonsense method before on here

Didn't know that

[Hex69]

What's wrong with an Italian tune up?

[zollaf]

when you have taken your boost pipe off, thats the black rubber hose you must have unclipped, you may have dislodged one of the vacuum pipes that controls the turbo. that is unless you have bent a con rod by spraying water in to the engine, it only takes a small amount to do damage . what you have done is actually a really daft idea. i would recommend you don't do it again. if you want to clean the car of carbon, do as hex says.

[Kar Krazy]

A diesel engine works by compressing air into a space over fifteen times smaller than normal. Water doesn't compress, so the moving parts will get damaged trying to compress it. As Zollaf said, it is very likely that you have caused serious damage to your engine by bending the connecting rods.

If you want to clear the EGR valve and intake manifold of the oily carbon that builds up in high-mileage diesels, take them off the engine, get some carb cleaner and good rubber gloves, and spend a fun morning gently scraping the inside of these components. It's a good idea to get a set of new seals and gaskets as well. Oh, and wear clothing that you don't mind throwing away.

Although in the case of your engine, I'm afraid that a rebuild or replacement of the entire unit is possibly going to be needed. It's a real shame you didn't put a post on here saying what you were going to do before you did it, so we had a chance to warn you that it was a really bad idea. I hope that it's only a vacuum pipe come loose that's causing the power loss, like Zollaf said.

[zollaf]

i had to do this yesterday to a customers arl powered golf. removed quite a lot of sludge from the egr and manifold, then fitted blanking plates to the egr to stop it happening again.

[Kar Krazy]

It's a horrible job, Zoll, I take my hat off to you getting stuck in. The results really speak for themselves, don't they? It made my 60k miler 2.2 TDCi Mondeo as good as new: far smoother, and the dyno showed I had increased the power from 142 BHP to its original 155. Then I added Bluetooth, a decat and bigger intercooler...

[zollaf]

oh so well worth it. but after doing one ( i have done many), you soon realise that whatever chemicals you throw at it, only elbow grease really works, physically scraping it off. this leads to me to be able to say that all of these magic cleans, terra clean et al, are snake oil maybe they do make a small difference, but not as much as a proper clean by hand.
lets hope the op doesn't need an engine rebuild after trying the old water trick.
incidentally, its te same as driving through a flood, and cars always run worse when they have been driven through a river.

[Kar Krazy]

Yes, the first thing it reminded me of was the old advice, "Keep your vehicle speed low and your engine speed high through a flood" because of getting water in the air intake and avoiding stalling.

I've heard some good stories about Terra Clean, but probably because the carbon in the combustion chambers is a far cry from the sticky goo in the EGR and manifold!

It's this EGR business combined with the DPF trouble that made me go for a petrol motor now that my daily commute is just over 5 miles. I've tried cycling but some drivers are lethal! Then there was the day I had used the bike and my boss asked me if I would stand in for him collecting a bloke in a wheelchair (plus suitcase) from the airport...