Since it seems like my motor is really on the way out after running on a burnt valve for an extended period of time, I'm thinking about picking up a used engine and rebuilding it. Its been running really rough in the morning lately, pretty much on 4 cylinders for the first 5 minutes or so.

Based on what I've read, for a decent rebuild I'd need:

New Pistons and Rods
Replace Cylinder Liners
Crankshaft Tested
New bearings
Replace valves, seats and seals
timing chain, guides, sprockets, etc
Gaskets...

Is there anything I've missed? I'm planning on getting a used engine from the part yard for a long term project over whatever life my current engine has left in it. I'm just going to drive it into the ground since I'm petty sure the misfiring has bent a rod.

I can probably budget around $3k over the next 9 months or so, and the old motor should make it for at least that long, I only have one car and need it daily...


This does not mean the turbo project is on hold. Still working on it, and will test on current engine if I have it set up before the new one is ready...

$3k isn't quite enough.

$1,250 alone for 5 piston and ring sets.
$250 valves
$175 liners
$120 bearings
$105 chain tensioner
$75 chain rails
$50 headgasket
$50 valve guides
$45 Timing chain
$35 oil pump chain
=$2,155 for just the hard parts. That doesn't include any shipping, machining, liner pressing, an injection pump rebuild (Around $1000 on its own), turbo rebuild, minor gaskets/seals or special tools.

Rods are a non-wear item. They don't need to be replaced unless bent or damaged.

I think I may go through with this anyway, maybe over a longer term. A head rebuild looks totally possable over summer break though, and I may be wrong about the oil consumption being a bent rod. What do you guys think about rebuilding a head and potentially putting it on a damaged block? Compression in cyl 1 is down to 200psi hot now, and combustion is leaking into the intake based on the crazy vibration my boost gauge has been doing for a while...

There are plenty of good used motors out there that are much cheaper then the routes your are suggesting. Plus the time of your car being out of commission would be shortened.

Unless you are talking about custom performance pieces, a regular rebuild just doesn't make economical sense to me. So my opinion is get a good low mileage motor with excellent compression and drop it in.

I agree. ~$600 vs $3000 for basically the same result in a fraction of the time and headache.

Most any good used engine will last as long as an owner can stand driving the same vehicle.

I think you can find the piston ring set for $900 But if I ever rebuild one I'm going to do liners & rings! unless the pistons are damaged I would reuse them the two engines I have taken apart the pistons looked like new no scoring or any thing else wrong just clean them check them and reuse them!!!

$900 very fesable from Mercedes and that was for 6 rings.

Check with rusty @ buymbparts.biz, chat him up online about the pricing. Also check with MB Classic Parts center in Irvine.

I vote for a good used engine with verifiable compression numbers.

http://atlanta.craigslist.org/eat/pts/1618066377.html

(03-01-2010 09:55 AM)winmutt Wrote:  http://atlanta.craigslist.org/eat/pts/1618066377.html

Thanks! I just emailed the guy, might be interested in some of the other parts too if its a SD...

http://www.autopartsworld.com/mercedes-benz_parts.html

This site is loaded with parts for pretty fair prices. choose your car.

What kind of machine work would be needed? Press out - Pressing in of the cylinder liners, messing with the valve train lifters/tappets/springs/retainers/guides/valves, and headwork. Plastigauge the crank/rod bearings and see what size replacements you need. Do the liners need to be honed?

(03-01-2010 11:13 AM)300SD81 Wrote:  

(03-01-2010 09:55 AM)winmutt Wrote:  http://atlanta.craigslist.org/eat/pts/1618066377.html

Thanks! I just emailed the guy, might be interested in some of the other parts too if its a SD...

LMK if you want to borrow my compression tester.

Take a look at Germanimportedparts as they seem to have good pricing on a lot of items..not sure if they have pistons...I know i have seen several engine parts listed.

(03-08-2010 08:23 AM)winmutt Wrote:  

(03-01-2010 11:13 AM)300SD81 Wrote:  

(03-01-2010 09:55 AM)winmutt Wrote:  http://atlanta.craigslist.org/eat/pts/1618066377.html

Thanks! I just emailed the guy, might be interested in some of the other parts too if its a SD...

LMK if you want to borrow my compression tester.

I have one, but thanks anyway. Do you happen to have an engine lift/stand?

Stand yes. I had a hoist at my house forever but the owner took it back.