OM606 N/A water injection for carbon removal - PeachParts Mercedes-Benz Forum

mwoodland · #1 03-10-2014, 01:20 PM

Not to start a flame war, but I've read here that water injection works well for removing carbon deposits in a diesel engine.
I've also read moderator interventions debunking it as crazy talk, dangerous, and potentially injurious to the engine. (and have watched videos of guys pouring water straight in, running a garden hose up the intake, etc..)
I've also read enough on the horrors of OM606 glow plug removal - seized due to carbon, to ask the question a different way..
OM606.910 N/A (no turbo)
In order to confine the treatment to 1 cylinder at a time, I propose to:
1. Remove intake and cover the intake ports with a section of plastic window screen - this will prevent anything from being dropped or sucked in while running.
2. Raise engine speed to a sustained 2500+ RPM.
3. Spray a fine mist of water into each intake port (or live steam, from a hand held steamer), quantity to be determined.
The intent is to steam-clean the cylinder, hopefully cleaning the glow plug "chamber" in the process, allowing for easier removal.
I wouldn't try this with a turbo, as I wouldn't want to strain any dislodged carbon through the impeller, but as a N/A engine, I think it might have merit.
I would combine this with the "usual removal procedures" for OM606 glow plugs, PB Blaster / Kroil, etc., hopefully without having to resort to the "usual extraction procedures for broken GPs", of which I've read way too many.
Any BTDT experience welcomed, and if not a good idea as-presented, why not?
Flame suit on..

Mxfrank · #2 03-10-2014, 02:21 PM

Water injection has been used as a minor performance booster for many years. In engineered systems, a precise quantity is injected. The water vaporizes to form steam, which expands inside the combustion chamber to produce a bit of a performance boost. It also cools down the combustion process, allowing more fuel to be packed into a turbocharged motor. But the key term is "engineered system".

The idea of spraying an arbitrary amount of water into a diesel motor is idiotic, that's the word. If you manage to get enough steam generated, you can blow the head apart. But that's not likely either, In Mercedes engines, combustion doesn't even occur in the cylinder...it occurs in the prechamber. Nothing you spray into the manifold or air intake will ever reach the inside of a prechamber. Nor will water have any effect whatsoever on the oily deposits in your manifold.

Another question is, why bother? If you're changing injectors and plugs, you can clean out your prechambers as you wish. But you'll never reach a point in ordinary driving where your prechambers become so clogged that you can't run. Don't obsess about something that's not going to be trouble.

mwoodland · #3 03-10-2014, 02:35 PM

My only "obsession" is the 606 glow plugs.
I've never had them out, and want to inspect and anti-sieze the threads before they need to be replaced, rather than wait for them to fail and be too locked in to remove.

GregMN · #4 03-10-2014, 02:43 PM

There is a port in the intake hose from the air cleaner box to the EGR valve body. The port is occupied by a intake air temp sensor. Remove this sensor and unplug the vacuum line from the EGR flapper valve. Plug the open vacuum line.

You can make a water injector out of your windshield washer reservoir and pump. I use a 12v plug that I plug into the lighter outlet to power on the pump. I use an old injector line to make a nozzle. I hammered the end flat, hooked it up to the water to test it. I ground the end open until it sprayed water the way I wanted it to. I don't know what to tell you about volume per minute, it just looked like enough, but not too much.

I drove the car until up to temp. I then plugged in the power to the pump for a few seconds at a time while driving under power. I have also done this sitting in the driveway at 4000 rpm. I watch for white smoke ( steam ) an turn it off when I see that out the exhaust. When it clears, I give it another dose.

It loosens stuck rings. It helps seat new rings. I have had success doing this for those reasons on 3 different engines. '95 606 N/A, '96 606 N/A, 603 turbo (post turbo with a higher pressure pump, 50psi )

I do not know if it will have any effect in the pre-chamber on the glow plugs. Vapor introduced into the intake DOES reach the inside the pre-chamber.

mwoodland · #5 03-10-2014, 05:10 PM

Perfect! Pictures even!
That was exactly the kind of data I was looking for.
Someone that had actually been there / done that.
My only concern with that was wondering what the distribution would be like to cylinders 1 and 6, which is why I was going to pull the manifold and treat each cylinder individually with an atomizing sprayer.. or go with live steam.
About how much water do you think you consumed on the treatment?
A quart / half a washer tank / whole tank?
I was thinking 1/2 qt - 1 qt per cylinder (total), done in stages, like you did.
Did you have occasion to pull any of the GPs / prechambers after the "steam cleaning"? Just curious to know how you verified it got into the prechambers.
I'd also consider this if I were going to pull the head for any reason.. Clean the internals before the teardown.
I've already blocked the EGR, pulled the EGR butterfly, and cleaned the intake manifold and intake ports in the head.
Thank you!

rscurtis · #6 03-10-2014, 05:43 PM

Unless there's something wrong with your engine, like extreme oil consumption, there shouldn't be any removable carbon deposits.

mwoodland · #7 03-10-2014, 07:52 PM

No problems, and I want to keep it that way.
I want to do a PM on the GPs, pull them, clean, ream the carbon out of the GP holes and anti-seize the threads.
One of the issues on the OM606 engine seems to be that the GPs get locked into their bores from carbon, then snap off on removal.
At that point, extrication methods run from gutting, drilling and tapping the GP body and using a puller, to having the stealership do it, to pulling the head and having a machine shop do it, to having to replace the head if the drill bit wanders off center too far..
An ounce of prevention..
I prefer to head off potential problems before they become real problems.

GregMN · #8 03-10-2014, 10:07 PM

I ran about 4 gallons through to seat the new rings in the 603.
I ran about 1 to 2 gallons through to free up stuck rings in the 606.

If you do not know you have a problem, I would not do it.
You can access 1 or 2 glow plugs by just removing the crossover pipe.
With the engine hot, try to remove one of those to see if you even have a problem.

dieseldiehard · #9 03-11-2014, 01:21 AM

If you want to reduce the potential for stuck glow plugs just replace them periodically, say every 75K miles or when one goes open and you see a fault light plan on replacing them all. Every other change interval remove the injectors and see if the pre-combustion chambers are getting plugged up. They do get plugged, as I found after about 50K miles of hard driving after rebuilding my 87 OM603. I think city driving is also a factor as I did some of that but no Italian tune up will reduce the carbon after its built up on the glow plugs and in the PC's, its like lava rock in hardness

I've seen a PC from a 603 with the ball burned off completely, it must have vaporized. I am certain they had not been removed from day one on that engine, based on a zero maintenance appearance on that car. The engine was sent to Metric Motors for a complete rebuild.

Sadly I have come to accept that these diesels are not completely free of some maintenance issues, including the PC carbon build up and in the later engines especially stuck glow plugs. The longer you let those plugs stay in the head the more carbon builds up on the shaft and that makes removal very difficult, the threads are not the issue here, especially if one puts anti-sieze on them when installing them, its that nasty build up that causes problems. Removing a stuck GP in the OM606 and similar engine requires patience, lots of solvent and possibly luck in screwing them out, actually you should screw a stuck GP in and out many times until the carbon gets worn down and it comes free. Give that job to a mechanic that is under pressure to finish before lunch or within a time allocation and if some GPs are really carboned up its almost a guarantee the head will have to come off and be sent to a machine shop to remove the broken shank.

I seriously doubt the water steam treatment will do anything except endanger the head gasket. If you do set out to do it please promise to let us know the outcome and to be scientific one should remove a PC and examine it after the procedure to see if it was effective.
DDH

sokoloff · #10 03-11-2014, 10:04 AM

Don't create more work and problems for yourself. Just change the plugs on a hot engine and you should not have any major problems.

Maxbumpo · #11 03-12-2014, 12:54 PM

+1

Quote:

Originally Posted by sokoloff

Don't create more work and problems for yourself. Just change the plugs on a hot engine and you should not have any major problems.

Len speaks from experience, the real "secret" is to get the engine nice and hot, and then carefully remove the plugs while the engine is still hot. They seem to break at torque above 35 ft-lbs, so set a torque wrench at a lower value when it is time to do this job (when you need to replace a plug due to failure).

Water/steam into the head will only clean the valve/cylinder/piston/rings, it will NOT get into the pre-chamber where the glow plugs live.

Getting to the carbon on the glow plug tip could be achieved going through the injector hole.

Practicing good engine hygiene may help reduce carbon build-up:

1) Don't allow the engine to sit and idle, especially after a cold start. Once oil pressure is normal and engine is running smoothly, drive off gently and try to keep RPM low until full operating temperature of the oil is reached.

2) WOT acceleration from zero to high-way speed (i.e. Italian tune-up) should be done periodically when the engine is fully warmed up, and if any black exhaust smoke results, repeat until the smoke clears up. Climbing a long steep grade in high gear is the best, especially if this causes engine temperatures to rise (but not overheat). The idea is to put a high load on the engine at high speed, and BURN out that carbon. An engine with severe carbon build-up may expel flaming chunks of carbon when done right...