OM606 (95 E300D) Plastic retainer piece fell into the combustion chamber - Page 2 - PeachParts Mercedes-Benz Forum

GregMN · #16 12-21-2017, 01:41 PM

Quote:

Originally Posted by torsionbar

The risk is in the foreign part preventing a valve from closing, and then piston collides with valve.

That would be a risk I would be willing to take. The piston would collide with the valve and crush the plastic piece. I do not think that any damage would be done to the piston or the valve.

That said, I would not make that decision on a customer's car or a friends car. I would leave that up to them.

Bengoshi2000 · #17 12-22-2017, 07:02 AM

"I would start it and run it."

I've never had any experience with foreign objects in the combustion chamber, removed a head, done a valve job... etc. So take my opinion with a grain of salt...

At the speeds the piston moves, I think that plastic piece could damage the piston head or the valves, valve seats... etc. I.E. I can throw a paint ball at you from ten feet w/ no ill effects... shoot it at you from ten feet... it's going to bruise and break the skin (not to mention the fact that you'll likely lay an arse-whippin' on me shortly thereafter).

I'd exhaust (pun intended) every possible vacuum or other removal options before cranking 'er up.

t walgamuth · #18 12-22-2017, 07:23 AM

The top of a piston is surprisingly thin and its aluminum so I'd want it out of there. It might be as thin as 1/8".

GregMN · #19 12-22-2017, 10:30 AM

I have experience with things in the chamber. The tip of 2 pre-chambers broke off and were banging around in there for a while ( in my mind "a while " in a running engine could be 5 seconds, it happened for the previous owner, so I don't know ) . The engine still ran. I drove it 70 miles home. It did not run well because of the broken off pre-chambers, but the pistons and valves were fine. The top of the pistons looked like someone took a hammer to it, with little divots marks in the top, but no material seemed to be missing. Based on that experience, I would run it with a piece of plastic in it.

Again, I would, doesn't mean you should.

thinfilmboy · #20 01-11-2018, 02:41 PM

Thank you Everyone for your inputs. I finally got the plastic piece out and thought I'd write a quick follow-up...

While rotating the engine manually I noticed that near top dead center of the cylinder with the plastic piece, the engine was momentarily harder to turn, which meant that fallen plastic piece was actually interfering with piston motion. So I rotated crank until intake valves were opening, but piston was still near the top. Then I cranked up the compressor to 150 psi and started squirting bursts of air into one intake while popping the vacuum suction on the other intake.

It took about an hour of bursting air and popping the vacuum hose until I finally felt the plastic piece getting sucked through.

pimpernell · #21 01-11-2018, 02:45 PM

Quote:

Originally Posted by thinfilmboy

Thank you Everyone for your inputs. I finally got the plastic piece out and thought I'd write a quick follow-up...

While rotating the engine manually I noticed that near top dead center of the cylinder with the plastic piece, the engine was momentarily harder to turn, which meant that fallen plastic piece was actually interfering with piston motion. So I rotated crank until intake valves were opening, but piston was still near the top. Then I cranked up the compressor to 150 psi and started squirting bursts of air into one intake while popping the vacuum suction on the other intake.

It took about an hour of bursting air and popping the vacuum hose until I finally felt the plastic piece getting sucked through.

Fantastic piece of work, and great news!!!!!!!

Maxbumpo · #22 01-11-2018, 04:10 PM

Yes, that is great news!

I wonder if applying the vacuum to the intake valve runner while rotating the engine so that the valve opening inside the cylinder got larger and larger would work. I'm thinking that the narrow initial opening of the valve would have higher air flow and the plastic piece would be closer to the top (on the piston) and so would get sucked and held at the opening, until the valve opening was large enough for the plastic piece to pass through.

thinfilmboy · #23 01-11-2018, 05:12 PM

Quote:

Originally Posted by Maxbumpo

Yes, that is great news!

I wonder if applying the vacuum to the intake valve runner while rotating the engine so that the valve opening inside the cylinder got larger and larger would work. I'm thinking that the narrow initial opening of the valve would have higher air flow and the plastic piece would be closer to the top (on the piston) and so would get sucked and held at the opening, until the valve opening was large enough for the plastic piece to pass through.

Maxbumpo, that is exactly what I ended up doing. With the intake valves just starting to open, and bursting air into the cylinder, you could see the little piece fly in and out of sight.

vstech · #24 01-11-2018, 09:45 PM

Sweet indeed! Glad you got it out safely.

torsionbar · #25 01-11-2018, 10:28 PM

x2, glad to see you got it out. Something thin and flat like that surely would have got in a valve and caused some nasty metal on metal action. Well done!

Texasgeezer · #26 01-17-2018, 01:52 PM

After reading this thread today, it makes me doubt if I was careful enough during the removal of my intake manifold.

I'm pretty sure after I removed the black plastic oil vapor plumbing pieces that I blew off the area above the intake manifold, but can't definitely remember doing so.

Next time I'll make sure to remove the fuel line metal brackets and clips before removing the head. All of my plastic clips were broken and pieces found behind all but one metal mounting bracket. And, will also make sure to thoroughly check and clean the area above the intake manifold.

There is a 'pad' shim part # A6010780386 for my car that attaches to the metal bracket and sits beneath the injector lines. This is used to provide a cushion/protector for the back of the injector line. After reading this thread I'll buy new ones and maybe prevent a future problem with the injector lines by holding the lines a little tighter.