I finally got the head off my 82 240D & I found a hole in the third piston! It's pretty small, maybe 1/8" dia. & goes down pretty far. There's a bunch of metal pieces fused to the top too. The other cylinders look fine. I couldn't feel any scoring on the cylinder wall & the valves looked OK from what I could see.
Is this engine worth fixing? From what I know, I can pull the oil pan & replace the piston from there. I checked on fastlane & they only have piston sets, are you supposed to replace them all at once when something like this happens? How bad a job would it be?
Thanks for any suggestions/advise!!

Mike

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Michael Roth

1982 300TDT Wagon
1982 240D Euro!, 4spd manual-Parts car now, dead engine
88 Jeep Grand Wagoneer-fixing up for offroading
1989 Ford F150 (rust bucket) For Sale!
1953 Dodge B-4F, 1 1/2 ton Stake Bed (new restoration project)

do you plan to keep the car?
A used engine would be cheap and simple DIY.

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I have a 240D engine and tranny combo (automatic) sitting in my dad's shop
It ran AND we are going to do a compression check soon.

Brandon

Replace the piston!

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

Put some JB weld in the hole...call it good

JB weld has a melting point of 1200*F

Our compression (copression = heat) engines inside the conbustion chamber reach in excess of 4500*F , I dont think that It would work for very long...

I did enjoy the chuckle though, thanks,

Hehe...I am a future chem major so this I know

In all seriousness though...what do you think would make such a hole?

I've been talking to Leathermang & he thinks it was probably caused by a fouled prechamber/injector & I think he's probably right from the looks of it. looks like it was spraying fuel right onto that spot.
Thanks for the suggestions & laugh! I do want to keep the car if I can. I was thinking that if it's going to be too much to fix this engine, what about putting a 5 cylinder in it? Would it fit OK & mate up to my manual tranny?
Brandon, wish you were a little closer!

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Michael Roth

1982 300TDT Wagon
1982 240D Euro!, 4spd manual-Parts car now, dead engine
88 Jeep Grand Wagoneer-fixing up for offroading
1989 Ford F150 (rust bucket) For Sale!
1953 Dodge B-4F, 1 1/2 ton Stake Bed (new restoration project)

Interesting...the only hole I've ever seen through a piston was when I was servicing a buddy's Vespa (I'm his mechanic as I have rebuilt several). My diagnoses led me to remove the head and there it was, a hole through the piston. I was pretty surprised. Easy fix on a Vespa. Now as far as the metal pieces go, make sure they're not part of the valves. My boat's engine suffered a catastrophic failure last year that ended up being part of the #3 intake valve breaking loose, getting sucked back into the manifold, where it was then sucked into the #5 and embedded into the top of the #5 piston (pic below). This happened at ~ 65mph. It was the result of the intake manifold gasket leaking water and thus tempering the valve(s). As you can see from the rust in the pics, it had been going on for awhile and thus required a new marine base engine. Regardless of what you do about the piston, find the source of the metal and discover why it happened.

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1982 Mercedes-Benz 300CD
1982 Mercedes-Benz 240D - stick

AN OM617 will fit in there.
But; can you handle the power. LOL ROFL

I wish I was closer too

Interesting...sounds very possible though on the fuel issue. Its possible that the 240 could make it over there (engine) as the guy that owns it (a friends of dads) works at the same place as him, Evergreen Avaiation. They might be able to have it trucked over there sometime. Who knows...if it comes down to it, let me know hehe...

Any metal down in the pan too?

Is anyone going to Holler about that 4500 degree F statement ?
Anyone checked the melting temperature of aluminum lately ?

I'd still put another piston in and go with it if no other real damage is in evidence. Just because.

They do it regularly on large diesels.

Perhaps his was at 4500F, hence the hole in the piston.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

My guess about the hole was based on his initial description as having ' burned' a hole in the piston... but this could be a mechanical hole due to something like the pintle getting into the combustion chamber... or a piece off the bottom of the precombustion chamber.... all guessing is dependant on good examination of the piston when it is cleaned up.
I have suggested that with a hole that small.. if this is caused by something connected with the head as compared to a broken ring... that he consider drilling and tapping the hole and placing an aluminum plug into it... and put it all back together and drive it as far as it will go... then do all the pistons and bores at the same time...