Pro and cons of rebuilding the baby.... - PeachParts Mercedes-Benz Forum

mbzr4ever · #1 06-22-2006, 06:30 PM

First, if this is in the wrong section, sorry and mods please move it to vintage or where it needs to be.

OK, need some opinions from the great wise 240 aficionados on what to do with my 79 240D that "blew up". Consider:

1) The engine had about 300K miles on it when I let a "friend" drive it and he "blew up" the engine. That friend is now long gone, needless to say.

2) The auto mechanic says it would take about $2500 to put in a new engine. Sounds like he doesn't even really want to rebuild it, just wants to get a "new" engine and put it in. It was leaking oil big time. Knowledgeble mechanics to work on mercedes are very limited here.

3) I live in Hawaii, making it difficult to find a salvage engine, or to get one sent (maybe about $500 to ship). Mechanic has a lot of 5 cylinders and wants to put one of those in, I said no, want to keep it like the original. The same 4 cylinder engine around here would be rarer than a hen's tooth.

4) The car had the beginnings of rust, would it be worth saving? The rest of the interior was fine, had just replaced the driver's seat and put on brand new tires. For $2500 couldn't I just buy another 240D without rust on the mainland and ship it over (about $900 to ship)?

5) It is the w123, manual transmission, manual everything that my dad picked up in germany in 1979. I have memories of driving this car in Europe, so, it has a lot of sentimental value to me.

6) Am driving the 300e right now, so it is just sitting and its not like I need to have it fixed right away. Can't decide if this project car is going to be more trouble than its worth.

blueranger · #2 06-22-2006, 07:19 PM

keep it since it was your dads..

get out there and get to sanding on the rust... and put undercoat on it..

get the manuals and buy the parts and rebuild it yourself over the winter time.

DIY will cost a lot less and you will learn a lot...
also since you have another car you dont have to be in a hurry...

blueranger · #3 06-22-2006, 07:32 PM

i looked up the parts for a 79 240d... and
the rebuild will be easy for you...most people when they
rebuild they have to worry about measurements... the measurments
of the pistons, and the bore, is it out of shape. Well you could
go with new pistons for $500 dollars so no need to worry about
the measurements and getting the right sized rings. You could also
put in new sleves. So the pistons and new rings will match the new
sleves. The sleves are about 120 bucks and the rings are about 120 bucks.

New bearings on the bottom, a new timing chain, tensionioner, sprocket,
new oil pump....Send the head out to metric motors for rework... and you will
have a brand new engine...Or you could just order new valves and springs and
have someone on the island do the head...

2500 gives you plenty of room for a great DIY rebuild....

and If money is an issue you could probably keep your pistons, and oil pump that will save you 1000 bucks....You could do your own basic rebuild with new rings and sleves and new bearings and valve springs, head gasket and valve guides for about 700 bucks....

I think a metric motors rebuild would be over 5k not 2500...

gatorblue92 · #4 06-22-2006, 09:46 PM

fix it and restore it since it was your dad's car... thats what im gonna do with my 240D that was my grandmothers and also purchased new in germany

#5 06-22-2006, 09:58 PM

OK, hold on. What exactly "blew up" on the engine? Did it throw a rod, blow a headgasket, or what? Does it still start/run?

"most people when they rebuild they have to worry about measurements... the measurments of the pistons, and the bore, is it out of shape. Well you could go with new pistons for $500 dollars so no need to worry about the measurements and getting the right sized rings. You could also put in new sleves. So the pistons and new rings will match the new
sleves."

Yes, you MUST pay very close attention to measurments if you want it to run right when your done. It's not just "throw in the parts and go". The liners must be honed to match the pistons + oil clearance and there are many more measurments, torques, and clearances that must be used. Reading the Factory service manual cover-cover is a MUST before you open up the engine.

But, first and foremost, I'd track down that "friend" for some compensation (Money or otherwise). Sue the bastard if he/she won't cough it up.

blueranger · #6 06-22-2006, 10:34 PM

if you rebuild your engine and reuse your pistons and dont replace
the sleves then measurements and honeing are very important. You will
check these measurements to determine if you need to buy over sized
rings.... but if you replace the sleves, replace the pistons with new pistons
then you will also be able to use the standard rings. You will have brought the engine back to the factory spec of a new engine....

You will have to measure the connecting bearings. Since you will have a new piston and an old crank shaft...i dont know what the price of a new crank is.

becareful rebuilding can be done at any level you desire. You can polish and balance and manga flux, and blue print and X ray, and do all kinds of fancy things. And for a race car these may be good things... But on a basic old diesel you probably just need new rings, a head gasket, and new valve guides. All the rest of this stuff is gravy... So just how much gravy do you want... If the car is special and you want the full gravy boat then go get yourself a metric motor.... they probably do the best work...

I have 267k miles.. and my plan is just a new head gasket and oversized rings, on the first rebuild, at 300k... on the second rebuild about 400k I will replace the sleves... and on the third rebuild about 500k I will spring for new pistons...So to each his own....

mbzr4ever · #7 06-23-2006, 02:16 AM

Quote:

Originally Posted by ForcedInduction

OK, hold on. What exactly "blew up" on the engine? Did it throw a rod, blow a headgasket, or what? Does it still start/run?

the mechanics don't even want to bother with finding out the exact problem and what needs to be replaced. they just want to buy a "new" or put in an engine they have ( a 5 cylinder) and charge me for the installation. verbal quote was $2500. said it would take about a week.

I had it towed back to my property, as it was leaking oil bad, and disconnected the (new) battery. I'm going to dig into it over the holiday weekend to get a better assessment of the damage.

t walgamuth · #8 06-23-2006, 11:09 AM

while i admire the spirit of the folks advocating a do it yourself rebuild, a 240 motor is nothing to do for your first motor, imho. i am an advanced hobbiest with over forty years of car hobbying and i would not do it myself. the sleeves have to be pressed out with an 80 ton press. then new ones have to be pressed in. the block has to be decked after the sleeves are in and the sleeves bored to match the pistons.

this is to say nothing about the fact that if you have a broken rod you probably need a block.

the best thing in your case sounds to me like finding a running driving parts car with serious cosmetic issues. get an experienced diesel mb person to check out the motor for you... then buy the car and swap the motor. this can be done probably for the cost of parts for a re build not to mention the cost of finding a good block.

swapping a motor is well within the abilities of a slightly advanced neophyte hobbiest.

good luck

tom w

coldwar · #9 06-30-2006, 07:45 AM

Quote:

Originally Posted by mbzr4ever

the mechanics don't even want to bother with finding out the exact problem and what needs to be replaced. they just want to buy a "new" or put in an engine they have ( a 5 cylinder) and charge me for the installation. verbal quote was $2500. said it would take about a week.

I understand wanting to stay original, but I wouldn't rule out a 5 cylinder. A lot of guys here (me included) would be grinning like this

to have a 5 banger mated to a manual transmission, especially in a car bought in Germany with all Euro spec - there were no 5 cylinder cars with manual tranny imported to North Amarica (am I right?).

The 5 banger sounds awesome- a very unique drone when accelerating, especially if you strip down your exhaust system a little. To have that sound mated with a free-wheelin' manual would be even better I think.

Dave
1976 300D (Automatic of course)

JimmyL · #10 06-22-2006, 10:37 PM

Quote:

Originally Posted by blueranger

keep it since it was your dads..

100% correct. Not even a discussion here.

Quote:

Originally Posted by blueranger

get the manuals and buy the parts and rebuild it yourself over the winter time.

Uhmm, he's in Hawaii. There is no winter time!!

Palangi · #11 06-22-2006, 10:41 PM

Quote:

Originally Posted by JimmyL

Uhmm, he's in Hawaii. There is no winter time!!

Winter is when the waves get taller.

mbzr4ever · #12 06-23-2006, 01:43 AM

wow, I'm liking what I'm reading....of course, that's the beauty of these cars. I've had no qualms about working on it before, the little stuff anyways. But an engine rebuild? Sure, why not??? And I just might learn a thing or two more about this classic vehicle.

BTW, I'm female (or a sista, as they say here)

PatricdeBoer · #13 06-23-2006, 02:09 AM

Wow, not too many women on this forum. Right on!

mplafleur · #14 06-24-2006, 10:02 AM

Quote:

Originally Posted by mbzr4ever

BTW, I'm female (or a sista, as they say here)

You still got two arms and two legs and a brain, and you're prettier to boot.

See? You have an advantage over us men.

Get the engine out. It's easy for that car. As for the sleeves, take the block to a machine shop and have them replace them and bore/hone them for the new pistons and/or rings.

With a manual and this forum to help with your questions, you should have no problem. The first engine I rebuilt myself was a 300D.

Think of your dad and make him proud. You'll feel better doing it yourself.

#15 06-25-2006, 11:12 AM

Quote:

Originally Posted by mbzr4ever

The auto mechanic says it would take about $2500 to put in a new engine. Sounds like he doesn't even really want to rebuild it, just wants to get a "new" engine and put it in. It was leaking oil big time. Knowledgeble mechanics to work on mercedes are very limited here.

Let's back up a little. Obviously, you're not going to get it back on the road for $200, and it's not clear what your mechanic is planning on giving you for $2500. A good quality rebuilt engine will cost around $5000, plus shipping and labor. A junkyard engine can be found for around $500, plus shipping. You may want to start by finding out what your mechanic is offering for that price. Does he have access to a good engine, or is he just guessing? If you know what you can get for $2500, then you will have a basis to compare your other options.