removing carbon buildup

[DieselPower]

Probably the easiest way would be to use a diesel fuel additive that states that it removes injector/cylinder deposits. It will have a detergent/solvent in it that will soften up carbonous deposits. Put some in a chemical resistant spray bottle and with the engine at the lowest possible idle spray the fuel additive directly into the intake manifold. Give it a good soaking and then shut it off, let set for a while and give the solvent in the fuel additive to do it's job.

You might try calling your local Ford auto dealership. Back when I worked for ford in the late 90's they still had a foaming upper cylinder solvent. It was sprayed into the intake system until the engine stalled and left to set for a half hour or so and then started. It worked great on gas carbon deposits and don't see why it wouldn't work in a diesel. The major benefit of this product is that the foam expands to completly fill the cylinder and back side of exhaust valves which means it stands a better chance of completly coating the deposits. If they still sell it it would be worth a shot.

 

[ultrarunner]

I guess no one uses walnut shells anymore?

 

[RoyJackson]

I guess no one uses walnut shells anymore?

Never heard of using walnut shells on an assembled engine. I've used them on heads and other parts (especially non-ferrous parts).

 

[ultrarunner]

Never heard of using walnut shells on an assembled engine. I've used them on heads and other parts (especially non-ferrous parts).

I have an original edition of Dyke's Automotive Encyclopedia with an entire section devoted to farm equipment. Somewhere in there it mentions using walnut shells blasting for carbon removal as an alternative to removing the head and using a carbon scraper.

I think my copy was published in the 1930's,

 

[RoyJackson]

I have an original edition of Dyke's Automotive Encyclopedia with an entire section devoted to farm equipment. Somewhere in there it mentions using walnut shells blasting for carbon removal as an alternative to removing the head and using a carbon scraper.

I think my copy was published in the 1930's,

Walnut shells (crushed) are used as a blasting media...so are crushed corn husks. I have personally used walnut shells while in the Navy (aircraft wheels and other components) and after the Navy. They do a great job in removing paint without any damage to the base material. I could definitely see the usage to removing a carbon build up on a head and have used that media for aluminum heads.
I'm just not sure how they could be used inside an operating engine without causing valve problems.

 

[DieselPower]

Ford had a factory walnut shell cylinder blasting set up back in the late 80's to early 90's. The one they had was for use in gas engines. You removed the spark plug, inserted the turnable blast nozzle, rotated the engine over until the exhaust valve for that cylinder was open and blasted it. The couple of times I used it, it appeared to work rather well on removing the deposits off the back of the exhaust valve (as observed with a bore scope). Problem with using it on a diesel engine is how would you get the blast nozzle in the small glow plug hole. I guess it wouldn't be to hard to fabricate a nozzle that would work in place of a glow plug.

 

[ultrarunner]

Thanks again DieselPower... you are always a wealth of information!

 

[dqdave1]

Dieselpower; I called a local Ford dealer; they do not carry the foaming cleaner any more. Do you know who made it for Ford? I looked at the seafoam website and they say to fill fuel filter with their additive and run it full strength to get good results.

 

[john_bud]

3M has a two part decarboning system. Only sold to professionals or so I'm told.

jb

 

[diyDave]

I would hesitate to use any oil based substance such as atf in a diesel engine, as it could cause an overspeed problem, from the oil becoming fuel in the cylinders. I take it the reason you want to de-carbon is that you can't get the glow plugs out due to carbon buildup on them that prevents their removal. I don't know what motor you are working on, but it seems to me that pulling the head is the safest option. Just my $.02