Precombustion Chamber cleaning?. - PeachParts Mercedes-Benz Forum

Olivier · #1 12-14-2009, 05:53 AM

Thank you to Diesel 911 and the great explaination on the precombustion chamber.
I am now wondering how it look for above?
The pin ball must be attached to the chamber to go in the middle but the fuel must flow/ pass thorough it to get to the piston. How is it attached?
I am wondering this as would some water injection pass the ball the other way around to clean the deposit in the precombustion chamber or the water injection would only clean the top of the piston and the valves?
How can we clean the precombustion chamber other wise?
Oven cleaner? Or that's too strong?
Or a water injection that would be in place instead of the injectors ( perhaps one at the time)and blowing a fine mist in the precombustion chamber would clean it properly?
Thank you.
Olivier

MS Fowler · #2 12-14-2009, 06:54 AM

My understanding is that the inside of a diesel engine immediately gets a coating of soot when first started. That soot generally does not accumulate further. The black exhaust is the excess soot being blown out the tailpipe. So if you were to clean it scupulously, as soon as you started it back up, it would look the same as before you cleaned it.

Olivier · #3 12-14-2009, 07:06 AM

Cheers Ms Fowler,
I am talking about hard build up carbon deposit here that might/ could over time form a solid crust in the precombustion chamber.
Olivier

Olivier · #4 12-14-2009, 07:11 AM

Quote:

Originally Posted by leathermang

UH.... I have not seen any mention of the TINY and RADIALLY drilled holes in the precombustion chamber...

I think those two adjectives completely negate the pressure of the spray coming out of the injector as a cleaning or power driving force.

I think the precombustion chambers need to be pulled and cleaned and the bore vacuumed. Even if that is not the cause of the present non start condition carbon should not be left in that location. The cleanliness of those holes is important... as is the existence/condition of the pintle ball which disperses the fuel towards them.

Leatherman, how do you pull out a prechamber on a E300TD 1997?
Thank you.

leathermang · #5 12-14-2009, 07:50 AM

If you have a precombustion chamber that information would be in the Factory Service Manual for your car..
I only own manuals for 617, 616, 615 and in the 123 chassis.

Olivier · #6 12-14-2009, 08:04 AM

Cheers.
Its a 606.
Someone must have it somewhere.
Olivier

layback40 · #7 12-14-2009, 09:55 AM

You don't need to remove the pre-chamber.
If it was blocked with coke from some one using some inappropriate fuel blend, you could remove the head, injectors & glow plugs, then block up the injector & glow plug holes in the head & use paint stripper (not the caustic type) the type with methylene chloride to soften & clean the coke out. High pressure water could be used to clean out the gunk when softened by the stripper. Several 1,000 miles on proper diesel would be an easier way to clean them out.
If you try and remove the pre-chambers you may cause damage to the head.

Diesel911 · #8 12-14-2009, 11:40 AM

This site only goes up to 1995 buy they way the Precombustion Chambers are removed is the same. However, I am not recommending you do so I am just answering the question.

http://www.ps2cho.net/downloads/MB%20CD/W124/Main.html

Alastair · #9 12-14-2009, 11:42 AM

Just use water-injection to Manifold/air-intake taking care of turbo if it has one....

It'll get to pre-chambers as it enters cylinder, it'll turn to steam in Hot engine and compress into pre-chamber with the air....

Just take care and dont allow more than say 10 Litres Per HOUR in fine spray form to enter whole engine, and only use at medium to high revs

....

Olivier · #10 12-14-2009, 11:52 AM

Hi Alastair,
I did it already like FBM, twice, but I was wondering if the mist would go into the prechamber or just stay above the piston, as if the fuel start to burn in the pre chamber, the pressure into it would be great and might prevent the mist to goes up before the piston goes down?
Cheers.
Olivier
Waiting on Nighty's spray bits then I'll do a proper WI drilled into the manifold above the EGR.

compress ignite · #11 12-14-2009, 11:52 AM

With a Mixture of: 1/4 (Straight) Techron, 1/4 Redline Diesel Fuel Catalyst and
1/2 (Lubro Moly) "Diesel Purge".

'Follow all your usual "machinations" for a FF replacement.

'Drive off down the Driveway...And "Drive it like you stole It" for about 1 hour.

(OR duct tape a very small plastic tube to your shop vac and use it to try and
pull out any debris from the GP opening)

Pulling the Pre-Chambers on a OM606 is an EXPERT level DIY and is fraught with
UnHoly RISKS!

Olivier · #12 12-14-2009, 12:00 PM

Diesel 911,
A big thank you again. I can see now what to do.
I would leave the prechamber in as I need to have the serrated tool and impact wrench to get it out, but what I might do next year would be to take the injector out and see from there how bad or not is the coking in there.
Great info there Diesel 911.
Cheers.
Olivier

Alastair · #13 12-14-2009, 12:09 PM

Quote:

Originally Posted by Olivier

Diesel 911,
A big thank you again. I can see now what to do.
I would leave the prechamber in as I need to have the serrated tool and impact wrench to get it out, but what I might do next year would be to take the injector out and see from there how bad or not is the coking in there.
Great info there Diesel 911.
Cheers.
Olivier

You dont get muck of significant amounts in pre-chambers believe it or not--no matter What fuel.

They run VERY hot that has the effect of burning off any crud anyway!

If the air will enter so will the steam from WI. There are a load of holes in the bottom end of pre-chamber to allow for air entry on compression and burning fuel to exit on power-stroke....

The pre-chamber is say around 25-30cc capacity and the main chamber around what, 20cc with piston at TDC....
--There will be more air in pre-chamber at TDC than in main chamber above piston....

Olivier · #14 12-14-2009, 12:13 PM

Thank you Alastair

I'll look at number 6 injector next year, just for my curiosity and see what is happening in this pre chamber. Removing the injectors is easy and only requiere a new heat shield washer

All the best.
Olivier

'83 240D · #15 12-14-2009, 12:52 PM

I've cleaned several of my diesel engines that were seriously hampered by carbon by using a makeshift propane injection for a while. While this has worked for me extremely well it's a bit dangerous if you are not sure about what you are doing so I cannot recommend it for everybody. The last rig I did this on was my 1987 Kubota tractor with a three cylinder diesel, my neighbor borrowed it and filled the fuel tank with hydraulic fluid instead of diesel, which caused the tractor to smoke like a coal fired train and when I got it back it was so full of carbon it wouldn't drive in road gear due to lack of power. I emptied the fuel, added one gallon of diesel with a can of sea foam in it, then I warmed up the engine to operating temperature and using a weed burner torch I fed it propane right into the air intake. It's critical to listen carefully because you will hear when you are giving it the proper amount, it runs smooth and quiet, much better than normal, a little bit too much and it will start knocking and you do not want this! I set the valve to deliver the proper amount of propane for about 1500 RPM and then proceeded to run the engine from about 1300 RPM to 2200 RPM in rapid bursts for about 20 minutes, every burst would give off a cloud of smoke and soot and after about 20 minutes it was running clean again, had great power and actually ran just as well as it did when I got it new. I've used this propane treatment on lots of rigs from small single cylinder generators to semi trucks, it's always done a good job. As a side note, my 240D went from a 0-60 top speed in about 5 minutes car to a rather fun car that has plenty of get up and go and will cruise all day at 85 mph no problem after the propane and sea foam treatment.