Photo below of spark plug out of M103 engine. Something has hit the end of the plug don't know what. Must have been a valve or piston, but how?

I just put head back on after doing heat gasket. Apparently I screwed something up. Before removing head engine was set at TDC for Cylinder one and cam grear sprocket was put back on exactly as taken off. Chain was put on at same place on cam gear as it was removed

What could have caused my problem and what can I do to fix it?


Edited: The spark plugs are all less than one year old but could it be that that one plug just goes to far in the hole that it threads into? I don't think I can shim it out since the plugs seat into hole, ie no washer.

Attached Thumbnails

 

I don't see how the piston can hit the spark plug unless the plug is too lorng or you had an object in the cylinder that does not belong.

Tom W

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I checked cylinder before I put head on and blew them out with air to make sure they were clean. That said it seems I did something wrong or knocked something in there when I fitted head to block. Is there anyway to check without taking head off.

I put cylinder 3 in TDC and could not see anything in there with pen lite and also put a magnet in to see if I could get anything out, but no luck. I don't have a borescope.

Is there any way a valve could have hit the plug?

OK, let's see if we can figure this out.

First, when did you know something was wrong? Does the engine turn over? Did you realize something was wrong when you first cranked the engine over? Did the engine run at all after re-installing the cylinder head? Did you leave the spark plugs in the head for the duration of the job? Give us some details and we will figure out what happened!

First, when did you know something was wrong?
When I started the engine and I heard what thought was valve lifter noise.

Does the engine turn over?
Yes

Did you realize something was wrong when you first cranked the engine over?
Yes

Did the engine run at all after re-installing the cylinder head?
Yes, I was thinking maybe the valve lifters need to pressurize.

Did you leave the spark plugs in the head for the duration of the job?
Yes

The other plugs look fine?

I would work on the premise that there is an object in the cylinder. My favorite machinist has a little periscope he can put in places like that to look around, maybe you can borrow one.

Oh and in case you are feeling like a knuckle head I once dropped a 3" stud into a cylinder and forgot it was there and so when i cranked the engine over it fell in there and then pushed a hole in my piston. Ouch! That cost me about 2k to fix. I had to buy a piston and all new bearings plus have the block stripped and cleaned IIRC.

Just don't run it this way and you wont spread debris into your bearings. (like I did).

Tom W

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Since pistons and valves are hooked together, even if incorrectly, and spark plugs can't move, I'd say that all the plugs would exhibit this damage if it was caused by a piston or valve. I think the damage was done while the head was off or there was something foreign in that cylinder.

A valve head could hit the proper-length plug, if it separated from the stem. But in that case, the engine is unlikely to turn over with the starter.

exactly, If you're planning on doing this in your driveway, i.e. on your back, pull the engine and trans as one unit. Use a load leveler so you can tilt it to clear the core support! As I started reading the thread I was going to guess one of the guide pins got into the cylinder but I guess those hose clamps can be just as nasty!

__________________


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

ron... are you really going to attempt this yourself?

__________________
1989 300ce 129k
( facelifted front,updated tail lights, lowered suspension,bilstein sports, lorinser front spoiler, MOMO steering wheel, remus exhaust,stainless steel brake lines). (Gone)

1997 s320 154k (what a ride). Sold with 179k miles. Replaced with Hyundai Equus

1994 e320 Cabriolet 108k



1972 280se 4.5 153k Owned for 12 yrs, sorry I sold it


[/SIGPIC]

Yes, that's the plan. Of course it's subject to change. My new detached garage is not completely done and lift is not in so I may have to have my friend who owns MB shop lift motor out of donor vehicle and place it into wagon. I can for sure remove motor from wagon and transmission if necessary. I can do all the other stuff.

I don't have a lot of time to work on car because I'm doing finishing type work on the house addition and then I'd like to get back on garage (photo below) to do painting and other work to finish it up. Basically the engine change project is not the highest of priorities.

Attached Thumbnails