tried searches and really have a hard time with the online manuals for basic info. Is it possible to change the rings with the engine in the vehicle? Man, I'm just tired of smoking up my neighborhood and can't afford a full engine rebuild right now.

Dale 240D

I am not the expert that some are around here but I dont see how you could do a ring job without yanking the motor. Making you issues worse, if you were to replace the rings without cross-hatching the cyls there is very little chance the new rings will seal and your smoke will be worse. Are you 100% sure its rings? Seems to me that hard starting due to low compression is more likely from bad rings than tons of smoke. How many miles on the motor?

My understanding is that you CAN do an in-frame ring job. You might have to jack up the motor to remove the big oil pan.

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My Truck.. 2007 DODGE, 5.9 Cummins, 6spd stick, 4X4. My car..1977 240D, OTHER WHEELS...1955 VW Oval window bug, European Delivery (Holland) with a 1700cc, 2 barrel, Porsche drum brakes. 1939 WILLYS Pick-up. 1967 Triumph 200cc Tiger Cub. 1976 Honda 550F 4cyl Motor Cycle.

To do a ring job, you will be 85% of the way to removing the engine. Might as well pull it, get it on a stand and make the job less hassle.

It is my considered opinion based on owning and reading both the 616 and 617 turbo paper MB manuals that you can not do it correctly in the car.
In ADDITION to that.. what has been said about it taking much more work to leave it in the car is very true....
There are some good threads about resleeving your engine in the archives... which is something it will probably be advised to do... your 240 sleeves do not cost near what the turbo guys would have to pay....

i thought the turbo sleeves were about the same price per cyl.

tom w

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[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.

Depending on what he finds he may not even need sleeves, just a glaze buster and a good eye for crosshatching. I agree though that it'd be easier to pull it, the crossmember keeps the long pan from coming off, which is necessary to get the rod bolts off, to pull the pistons.

my machinist and i have pulled down about five 616/617s. we have always needed to resleeve and were usually able to reuse the pistons, but at least once we had to replace the pistons, but i had good used ones that we used.

i would be surprised if rings only will work for very long.

these engines are reall y time consuming to tear down and reassemble. it doesnt make sense to short the rebuild if taking them apart. if money is too tight for a decent rebuild probably you should try to find a good used engine. these cars do rust and the bodies often go before the engines in the rust belt.

tom w

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[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.

Mustangman.... you clearly don't have a MB factory shop manual... so we will take that into consideration ... and are not familiar with the tolerances to which a proper rebuild needs to be kept...

Tom W is correct...

for sure if you need new pistons combined with new sleeves to get it right the non turbo pistons are way cheaper than the annular oil ring turbo pistons...
and often doing that will be cheaper than the machining ( if done correctly ) which would be necessary doing it the other way ... ( machining is necessary on new sleeves anyway because the shop manual expects each bore to be fitting to the particular piston which is going into it... )

Have you adjusted your valves and run a compression check? Serviced your injectors?

If you really do have a bad engine it is probably a lot cheaper and quicker to find a good engine. A parts car will be cheaper than a rebuild. Maybe could even get a wrecked 300D and make a swap.

is a 300d motor an easy swap in for a 240D? if it is ,i guess that would be a great way to go.
my experience in the past has been that with a lot of 'merican gas engines, you could do a reasonable ring job from beneath in a weekend and clean things up for about a year until either getting a new engine or doing a rebuild. sounds here like i might as well pull the engine. i'll do some searches on that. now of course if i do that that i'm going to be tempted to do everything else since "i'm already in there anyway". i guess THAT is what i was trying to avoid by just doing a ring job from underneath. i also wanted it to be just a weekend project. i'll do a search for resleeving as well. thanks guys.

dale

Dale, it is best when first stating your question to be sure and tell people certain things... like if this is a manual or auto... can make a big difference ... manual pretty straight forward... different years matchup with regard to vacuum lines or accelerator linkage ( a missnomer with regards to 240 auto's..LOL ).. check out Larry Bible thread on getting the most from your post at top...
With regards to American engines and possibility of doing it from the bottom.. I have seen this done in emergencies and it lasted a reasonable amount of time.. NO WAY that applies to these MB diesels !

just for the record you can't pull the pistons out from the bottom.

even if you could you would have to take the crank out to do so.

which would be tough from the bottom.

tom w

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[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 am in the process of pulling the engine on a '85 300D with 307k miles. It came in with a bad head gasket and in talking with the owner he wants an engine rebuild (new sleeves, rings, brgs, etc...). Looking at the interior of this car it looks like it just rolled off the showroom floor (that should tell you alot about the owner). Says it is his wifes car and she loves it. Anyway, I am going all out on this one and will probably end up doing alot more than just an engine rebuild - probably a full mechanical restoration. I have never met the owner face to face (he lives in NC) but can tell by talking with him that he is the type that likes things done right. It is a pleasure to work on cars that are owned by people like this.

Oh yea - you can get the pistons out from the bottom but not in one piece.

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Jim

you got me there.

heh heh

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.