I did something incredibly stupid tonight.

I was pulling the pre-chambers from my wifes 300D. To make a long story short, I was rushing to get them pulled before the sun went down.

I neglected to the glow plugs before removing the prechamber. Well I got one out and realized what I had done when I saw a clean swath down the face of the prechamber. I shined a light down into the cylinder and I can see shards of metal, likely from both the prechamber and the glowplug.

I am really not all that interested in pulling the head to clean this. Is it possible to just use a magnet to pull the bits of metal out?

The car has been having some odd power problems and I was hoping clean injectors and pre-chambers might help a little.

Any hope?

__________________
'84 300CD Turbo 132k (Anthracite Grey) - WVO - My daily driver - Recently named coo-coo-coupe by my daughter.
'84 300D Turbo 240k (Anthracite Grey) - Garage Queen
'83 300D Turbo 220k (Orient Red) - WVO - Wifes daily driver

I'm not a certified mechanic, but I did stay at a HolidayInn Express last night.

I wonder if you couldn't rig a small hose to a vacuum and vac any carbon or whatever out that a magnet wouldn't get? Or blow some air in there from an air compressor?

Do not use compressed air to blow in there...
Find a way to vacuum what you can....
then use oil to cause any chips which may be beside the piston but above the top ring to stick to the side of the bore... move the piston down by hand rotating the engine... and wipe with clean rag....

when finished, if you can find a boroscope, try that to see if you got it all out.

__________________


1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

Why not use compressed air? That was my first thought. Make sure the valves are closed, insert a thin tube connected to the compressed air line and blow out the debris. Are you concerned about swarf getting trapped between the cylinder and piston?

Exactly..you stand a very good chance of driving the debriss down alongside the piston...

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
---------------------
Section 609 MVAC Certified
---------------------
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

Just any type of oil? Or should it be thick?

What kills me is I was doing the swap in order to make a final decision on wether to let the insurance company total the car or not. The car has had a power problem that has plagued it since the day I bought it.

I'd let them total it and buy it back, but they are under the impression that they can get $1,600 in salvage for the car.

__________________
'84 300CD Turbo 132k (Anthracite Grey) - WVO - My daily driver - Recently named coo-coo-coupe by my daughter.
'84 300D Turbo 240k (Anthracite Grey) - Garage Queen
'83 300D Turbo 220k (Orient Red) - WVO - Wifes daily driver

I'm not a certified mechanic, but I did stay at a HolidayInn Express last night.

Leather: How do you get the clean rag into the cylinder, thru the prechamber hole in the head? Good luck.

James: First use a magnet. to get out as much as U can. Then I would have the exhaust valve open for any debris to go out of the cylinder into the exhaust system when using compressed air to clean out the cylinder. There will be very few particles <0.001" that would fit between the piston and the cylinder wall. Don't put oil in the cylinder, it will just make the particles stick in the cylinder.

P E H

at least on gas-burners with spark plug holes, a grease-coated tampon securely fastened to a piece of coat hanger often makes a great super-sized Q-tip in such situations. Give due credit to my wife for suggesting this solution in a similar crisis years and years ago.

Diesels do depend on extremely high compression pressures to run. And a scored cylinder can cut your pressure drastically, resulting in a cylinder that is "worn out". So I do agree that it is necessary to remove all the metal particles. I'm saying that a high pressure air blast directed into the cylinder, and then directly at the crack between the cylinder and piston should remove all the particles.

I also agree with the idea of cleaning the cylinder then turning the engine to lower the piston and see if there is anything else stuck to the cylinder.

" I'm saying that a high pressure air blast directed into the cylinder, and then directly at the crack between the cylinder and piston should remove all the particles."

We are talking about matter between the piston and the bore above the top ring...

Have you seen the demonstrations of air pressure which people like ' Mr.Wizard' put on ... like wetting two pieces of glass and trying to pull them apart ? The problem with pulling them apart is that ONE side has NO air pressure against it... and the other side and edges have approximately 15 POUNDS PER SQUARE INCH...

When you direct that air blast into the cylinder HOW DO YOU GET THE PRESSURE BEHIND THE PARTICLE... SO THAT IT IS EXPELLED FROM THAT NARROW SPACE BETWEEN THE PISTON AND BORE ? Otherwise you have the same pressure all around it keeping it from coming out of the narrow confine...and no pressure behind it... thus holding it into place...

Most top rings on pistons are not flat.... they slope so that pressure from above presses them outwards to help in maintaining contact with the cylinder wall... so most likely any junk will be forced to behind the ring.... then only taking out the piston and taking the ring off would afford a way to clean it...

James, the tip is probably something like Tungston... like light bulb filiments...
the powder is probably ceramic... which provides heat conduction away for cooling while providing electrical insulating properties at the same time... and which would powder when crushed...

"In fact the laws of physics state that an abject/particle in motion will stay in motion unless acted upon by another force."--Danny

First, those pistons travel fastest at mid stroke... and slow down to almost no movement for several degrees of the crank at both top and bottom of the stroke... which is why determining the TDC using the piston travel is a matter of measuring and marking several degrees before the top and finding the same distance the other side... then just taking half way between those spots to call TDC..

But concerning the above quote.... you have left out air pressure. That is the OTHER force.... and it rules the day down in that bore... even more so on a turbocharged engine...

Some of you guys think and worry too much. Wax on wax off. Grasshoppers go through life without undue burden.

Peter

__________________
Auto Zentral Ltd.

A similar thing happened to me and my C230k this weekend. I went to do a standard replacement of cyclinder 4 ignition coil and saw that the electrode tip was not on the spark plug. Could hear it rattling around when I turned the engine. Any suggestions on how to get it out?