a few more questions -- 300sd- a bunch of questions
 

car set for three years, I reinstalled injector pump as per book, I dont have a timing tool, so I set as per the scribed line. I also mistakenly removed the output boss ( the item on the IP that is held down with 2 nuts and studs ) for the number one cylinder. the engine was pretty hard to get started, but once finally running, seems to run rough and won't idle. does the setting on the #1 delivery boss ( OK I am sorry I don"t yet know the proper terminology ) cause a great deal of roughness if not set just right?
also the motor seems pretty quiet, almost like a gas engine. Did I mess up on reinstalling the IP ? OK another question, This engine has 265,000 miles and seems to blowby alot, at 1000 rpm if you place finger on the small hole in valve cover in a matter of 5 seconds it about blows your finger off the hole. seems excessive to me. Air cleaner insides are covered in oil, and also a bunch on the air cleaner. I can't find anybody to rent a compression tester from. and yes it seems to smoke a bunch. I am about ready to yank the engine out and investigate the pistons and rings. Can a guy do a cheap overhaul on one of these engines. less than maybe 1000 dollars?? will I most likely need pistons with this mileage??
:confused:

You've done good so far, you have it running. You need to properly time the engine. The drip tube is very inexpensive and allows you to do an adequate job of properly timing the time of delivery.

Don't take the engine apart for exploratory surgery until you have done a compression check. The blowby is definitely a bad sign, but don't condemn the engine until you set the timing properly and do a compression check. I think there is a possibility that if you set the timing properly and drive the car some, it could free up stuck rings. Several hot drain oil changes at about 100 mile intervals might free them up.

Unfortunately there is really no such thing as a cheap overhaul on these engines. Pistons cost about $150 each plus boring of the cylinders, the crank will probably be okay, but you will need new bearings, and don't even think about taking it apart without doing a valve job with new guides for $350 or more. I just can't imagine overhauling this engine for any amount near as low as $1,000. I have a 617 apart and have more than $1,000 or so in the short block alone, and that is with a good crankshaft that doesn't need turning.

Sorry to deliver all this bad news.

Best of luck,

jb - did you do anything with the fuel in the tank? Was it mt? I am hopefully going to get my "new" '83 240D home over the next week and am wondering if I should remove all the fuel from the tank, remove the tank, clean it real good and reinstall it. Anyone?
I plan on installing new fuel filters, glow plugs and adjusting the valves anyway.

Pistons can be reused as long as the new rings fit in the ring grooves with proper clearance. The top ring is in a steel insert, so if the engine hasn't really been abused, they are normally OK.

No cheap rebuilt, alas. Sleeves are on the order of $35 each (all MB diesels are sleeved -- keep the pistons and re-sleeve, bore to size).

Hard start, rolling idle, and low power with smoke at high engine speed indicate late injection timing. You could have screwed up the #1 IP sleeve, too, if you move the bottom plate too much. Will cause #1 IP piston to deliver the wrong amount of fuel and/or change the timing for that cylinder.

The scribed line will not give proper injection timing -- it is a couple degrees off, more if the timing chain is worn. Use the drip tube.

Fresh fuel will help, too. Diesel fuel doesn't really go bad like gasoline does, but it will grow algae if there is any water in the tank. The algae will plug the filters and gunk up the fuel lines.

If you get fuel when you operate the manual pump, I wouldn't bother with cleaning the tank. Just change filters a couple times if they plug. If you have trouble getting fuel to the IP, clean the tank.

reply
 

I actually believe the tank was empty, and thus the beginning of the reason I jumped to the wrong conclusion. Like I said in a different post I was out of the country and came home for a quick vacation. and jumped at the IP. I have worked on a bunch of big diesels ( equiptment, trucks and busses ) so I am not completely ignorant. I probably wound not pull the fuel tank unless I was getting a bunch of trash in the filters on a regular basis. I pressure washed the engine bay and complete bottom side of the car today ( the good part of owning a 12 car carrier, is I use it as a lift ) as I am still leaning toward a little exploratory surgery on the engine. HMMMMMMM ??

hey psfred -- do the liners just knock out or do they need to be pressed into the block

The liners are cut out with a boring bar, then new ones pressed in, then rebored to fit. These are just dry liners like machine shops use in most any engine block to repair bore damage.

I've seen where people have had good luck reusing pistons. I'm personally a little leary of this. I have had a piston ring land failure before. Pistons are very highly stressed in a diesel engine.

If the pistons pass close inspection, I guess it would be acceptable though. Inspect them CLOSELY.

Good luck,

Liners can also be removed by running a wide, sloppy welding bead up one side, with very little penetration (bubblegum welds are perfect). This causes the liner to shrink and they can be tapped out easily with a driver (you will need to make one). Many shops do just this, it's faster.

Sometimes you can also shrink them out with dry ice, but that is tricky.

To install, pack in dry ice for 20 min, then drop in. Make sure bores are CLEAN first, and make absolutely sure to push them completely down, or you will have to remove them (destroying them) and try again.

We take them out ourselves and have the shop install the new ones -- they have more practice and charge $30 each to remove the old ones.

Pistons should be perfect to be reused -- no deformation of ring lands, no cracks, no scratches from cleaning at the base of the ring grooves, and must have factory clearance (between ring and groove) with a new ring all round the piston. Also, no visible wear on skirts and correct diameter at the base. A pain to check, but the ones for my 300DT are $400 each!

Peter