M103 Interference or not
 

Hi
I've searched through the forum and didn't get e definitive answer as to whether or not the M103 is an interference engine or not. I'm in the midst of doing a head job and everything went well except at the last moment while pulling the head I snapped the upper portion of the chain rail (right side not the tensioner) and want to know if it is absolutely essential to replace the whole rail. I realize it would be the right thing to do, but with an enigine with 308K miles and planned retirment of the car in a couple of months I didn't want to have to pull the bumper and radiator and everything attached if it wasn't absolutley necessary. Thanks for any insight and info.

My fear would be the chain jumping ( I doubt it will) and slamming my pistons into my valves! Ouch

Thanks in advance

All Benz engines are interference engines.

Whether or not you replace that rail would depend on how much vibration you thing not having it in place will cause -- the chain isn't going to jump a tooth, but excessive vibration will cause it to fail much faster than normal, and I'm betting it's pretty ancient.

Peter

As far as I know
 

It's the original chain. In the world of MB's I think it's not too old, however the service manual supposedly suggests changing it every 100K miles. My head gasket has gone 2x in the life of the car once at 72K and again at 308K. I don't plan on driving it more than 15- 20K miles more (4 months of my driving).

What would you guys do?

thanks again

next mileage badge is 310,500 miles (500,000 Kilometers.....I'm so dang close!

Why are you going to retire it? Has it lost a lot of compression?

Keep it alive if you can... :)

Those single row chains really only last about 100,000 miles before they get too long and the valve timing gets late.

I would replace it, they aren't expensive.

Those 103's live forever (500,000 miles and up) if you keep good oil in them.

Peter

I'd love to
 

Space and money prevent me from keeping it alive. Honestly, if I found an enthusiast that would take it to 1,000,000 km I would sell it cheap as dirt with the clause that i could visit once in a while. best car I've ever owned and probably the best I ever will. I live in a place that doesn't have a driveway, so parking is expensive. Then if it needed to pass inspection I would have to do the following:

brakes $500-900
windscreen $300
and the tranny is original another $1500 soon

so with the idea that close to $3000 to keep it running and I can't easily keep it near by (parked at work when driving the W210)

I earned my 250K km badge and I would love to have my 500K km badge to memorialize the car

Alot more work?
 

To change the chain and rails, I have to pull the bumper and radiator right? Or is this something that can be done without pulling extra stuff off?

thanks