removing carbon buildup

[dqdave1]

How can you remove carbon buildup short of teardown. Glow plugs have carbon buildup and cannot not be removed. Are there any additives or sprays for diesels that can be used to remove carbon. I thought there may be something to spray into intake with air cleaner removed while engine is running to remove carbon.

 

[jjmarotz]

Short of a teardown I have never heard of any sprays or addatives that accomplish this. Excessive carbon buildup is a byproduct of un-burnt fuels. Everytime you see a diesel pickup or big rig belching out black smoke, guess what===that's unburnt fuel. If you think you have too much buildup this could be caused by a faulty or out of whack injector pump or carburator. I commonly, (on my old carbed pickups) will mash the throttle for a short burst with high rpm's to create a higher temp in the combustion chamber and valve train, than normal. The higher heat will burn out most of the excessive "CRAP" out of it, thus making it run better. Newer fuel injected and computer controlled engines don't normally see this problem.

 

[RoyJackson]

Boy, you've either got a lot of hours on that tractor...or a lot of idling time!
I've read that misting water in a gas engine can break up carbon deposits, but never heard of using this method on a diesel.
Have you talked to a diesel mechanic yet? The proper solution will probably be pulling the haed, but you never know until you ask.

BTW, I had to have my Ford Explorer's heads decarbonized a few years back...ain't cheap.

 

[RichNJKubota]

Be careful with that water mist. The water must be in vapor form. Water droplets have been known to crack hot piston rings.

 

[RalphVa]

I've seen my Dad pour water down the carb inlet to decarbonize a gas engine. Not recommended for a diesel.

I'd try using something called Chevron Techron red line. I've used it twice in my 1983 Benz to stop pinging at constant, medium speed. (That's all, just twice in 25 years and 205k miles) Worked both times. The pinging was likely caused by carbon buildup causing hot spots. You put the Techron into the diesel fuel. I'll work in one tankful if it's going to.

Ralph

 

[drtydeed]

We used to use brake fluid in the garages that I worked at (for gas engines). Simply poured into carbs at approx half-3/4 throttle. Worked great. Not sure if this method can be used on diesel.

 

[Farmerford]

Like Ralph, I used Chevron Techron in Mercedes diesels and it worked well, although you will probably need more than one treatment for heavy carbon. I recall that Chevron recommended only one treatment between oil changes, but I could be wrong.

The Mercedes dealer recommended the Red Line brand and it seemed to work a little better than Techron. And I don't think Red Line had a limit on how often you could use it.

If you can make it through the winter without changing the glow plugs, I would use Techron or Red Line in every tank (if allowed) and work the engine hard

 

[okie350]

Sea Foam works very well.

 

[montanaman]

How can you remove carbon buildup short of teardown. Glow plugs have carbon buildup and cannot not be removed. Are there any additives or sprays for diesels that can be used to remove carbon. I thought there may be something to spray into intake with air cleaner removed while engine is running to remove carbon.

Can you get them out enough to get anything to run down the glow plugs?? GM used to have a top engine cleaner that worked wonders. Had an engine on a stand to re-do the top end and we set it up so one bank of cylinders was level and poured just enough on each piston to cover the top. The next day, the carbon from the pistons was floating on top of the top engine cleaner and when we wiped it out, the pistons looked brand new.

Ken

 

[skipmarcy]

Can you get them out enough to get anything to run down the glow plugs?? GM used to have a top engine cleaner that worked wonders. Had an engine on a stand to re-do the top end and we set it up so one bank of cylinders was level and poured just enough on each piston to cover the top. The next day, the carbon from the pistons was floating on top of the top engine cleaner and when we wiped it out, the pistons looked brand new.

Ken

He's right, GM top engine lube was great for removing carbon, we used it back in the 1960's & 70's on Cadillacs & Oldsmobiles. Auto trans fluid works almost as well as the GM stuff, but I have never done a diesel engine with either one so I can't say for sure on that note. I have used water many times as well on gas engines but it would seem obvious that it would be incompatible with a diesel - not supposed to get any water in a diesel.

 

[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