new rings and sleeves only?
 

1983 240D -Alright, I've lost the rings in my #4 cylinder and have tons of blow by. My oil pressure is greta and I have no complaints with my head.
My question is does it make sense for me to pull the engine myself and send the block to a machine shop for new rings and sleeves and leave the bearings ,which seem fine, alone? I'm trying to do this as quickly and cheaply as possible and get her back on the road. she's only got about 200k miles on her and i can't justify a new engine, full rebuild or the uncertainty that would come with just dropping an unknown used engine in her.
My thought is, that if i just got a weird fluke ring mishap, everything else should be ok on an engine of this mileage.
am i nuts?

Dale

yup, nuts.
you will be replacing the piston too. rings don't just go bad for no reason. and they take the piston with them when they do go bad. that is, if it's the rings, and not just a hole in the piston anyway.

It'll also be cheaper to have the pistons made, rather than buy OEM.


A place like Diamond Pistons (Clinton twp. Michigan) can do it.

I have had five or six benz motors rebuilt and only one had pistons worn too much to reuse. The machinist can measure the ring lands for wear and make a determination if they are within spec or not.

Also probably good idea to check cam chain . Guides for same also are probably due.

The bottom end may well be good to go, but if the head is off I would have the valves ground and checked for wear and replace any springs, valves and guides that are out of service specs.

Tom W

pistons?? really?
 

hmm, i've heard that the pistons on this engine are pretty bullet proof. that was why i was thinking that i might get away with this.
re: the head, nope, that's called mission creep man. of course if something was hugely obvious, i'd take care of it, but i have no indications so far to think to expect that.
the timing chain and guide though is another matter. i can always pull the head easy enough in the future if needed. i just want to do what NEEDS to be done while i have the block out.
I.E i need to keep this job to under 1000 bucks. What do you think my odds are?Is the chain something that should/or usually is replaced about now?
thanks for the feedback gentlemen.

Dale

You can buy a good used 240D engine for well less than $1000.

In fact you can probably buy a whole rustbucket car for well less than $1000.

I'm speaking from personal experience. Just watch EBay and search on poor looking 240Ds from your area.

:)

Ken300D

New rings and sleeves are relatively inexpensive. It's the machining involved that is expensive. A used engine may be the least expensive route.

The chain, again may or may not be worn. The chain guides most likely need changing though.

Tom W

hmmm, ok, so chain guide, rings and sleeves is what i'm "planning for".
Again, guys, i don't want to just plunk in a used engine. If it costs me 500 bucks for one and then i have the same problem...
I just don't like the uncertainty that comes with someone elses used engine. My thought was, spend a little more, like 1000 bucks, and KNOW what i have. Sure, 2 years down the road i might need a head job, but I'll know my rings and cylinder walls are good, and then maybe 3 years down the road i need new bearings and crank work.
The body of this car is in beautiful shape and I'd like to preserve her, but 5 grand for a new engine from metrics is out of the querstion now, and i think a used engine isn't really getting me anywhere, just sort of treading water.
Anyone have any ideas about what i might pay to have new sleeves put in and the honing and planing required?

thanks,

dale

I agree that you are better off fixing a known engine than installing a junk engine if you are planning on keeping the car. Don't know about the cost.