Just bought a 1982 300D, has engine knock. - Page 3 - PeachParts Mercedes-Benz Forum

MrGiggles · #31 03-13-2009, 09:07 PM

Quote:

Originally Posted by Diesel911

I cannot answer "how often" because if the Engine is functioning normal like my car since 1984 with no problems.
Bearing failures are caused by lack of lubrication (not enough oil getting to the bearings due to low oil pressure on not enough oil), the oil getting too hot and breaking down (often due to a Engine cooling system failure), and the mechanical failure of some part (Bent Connecting rod, a bolt or nut holding a Rod or Main Bearing Cap comes loose and so on).

This happen to me in a gasser: I was driving a Car that had a leak at the seam of the Radiator. While I was on the Freeway the Seam split open. By the time I drove off of the Freeway (took 1-2 minutes) I had severly over heated the Engine and it was knocking.
When I took it apart I had ruined all the bearings an bearing Journals.
The over heated Oil had broken down and could not lubricate the Bearings.

I think I may have sourced another problem. My dad says he has never seen an oil pump without a screen on the bottom. He thinks the screen may have dislodged and plugged the oil pump starving the engine. Possible?

Quote:

Originally Posted by t walgamuth

With the bearings shot from running without oil I would not be surprised if the pistons are oK. The engine will have to come completely apart though as the metal pieces will have been pushed to every part of the oiling system. cam bearings could be damaged too.

The rods are an interference fit. Push them out with a press but you just heat the rod and insert a cold pin, IIRC.

I will be removing pieces to pull the motor tomorrow. I am also trying to locate an engine hoist. Once that is done I will update the thread.

vstech · #32 03-13-2009, 10:15 PM

My 617 had a screen on the oil pump. it's only about 1.5" around, you may have one and not realize it. it's nothing like a chevy/ford oil pump screen. mine was plugged with bearing pieces like you have shown.

MrGiggles · #33 03-14-2009, 09:44 PM

I worked today from 4 to dark and got the alternator, radiator, and some other small pieces off.

MrGiggles · #34 03-16-2009, 02:28 PM

I have hit a road block in the process. The motor is ready to pull except one thing. The last crossmember right before the U-joint on the transmission needs to come off to remove the shaft and tranny. The 4 bolts that hold it to the body are giving me trouble. The nuts on the other side were welded to the body but the welds broke and now the nuts just spin. I can't get a wrench on the other side to hold them either. What do you guys suggest before I torch them?

t walgamuth · #35 03-16-2009, 07:10 PM

I have always been able to grab it with something. vise grips often will do the trick.

If all else fails the hot wrench is quick and dirty!

MrGiggles · #36 03-16-2009, 09:47 PM

Im just going to leave the bolts there, the tranny will come out of them by removing a different bolt.

Does anybody know how the shifter linkage works? Is there an actual linkage or what? I need to get that unooked, the speedometer cable, and the motor mounts removed tomorrow. I have plans to get a hoist on Wednesday.

winmutt · #37 03-16-2009, 09:58 PM

It's an auto right? One piece of linkage no big deal. You get the oil cooler lines and speedo? Are you pulling trans with engine? Make sure your rear end is real high up.

MrGiggles · #38 03-17-2009, 09:49 AM

Quote:

Originally Posted by winmutt

It's an auto right? One piece of linkage no big deal. You get the oil cooler lines and speedo? Are you pulling trans with engine? Make sure your rear end is real high up.

It's an Auto. What is a one-piece linkage? I got the oil cooler lines of the oil cooler, the speedo cable I am doing today. Yeah, I'm pulling the trans with the engine.

You think I should jack up the rear end high?

rs899 · #39 03-17-2009, 10:14 AM

There's a rod that come down from the shifter on the tunnel to the selector switch on the right side of the tranny. Disconnect that by removing a small sheet metal clip. Yes, back end needs to be high and it will be nearly vertical when it comes out to clear the radiator support.

MrGiggles · #40 03-17-2009, 12:44 PM

Quote:

Originally Posted by rs899

There's a rod that come down from the shifter on the tunnel to the selector switch on the right side of the tranny. Disconnect that by removing a small sheet metal clip. Yes, back end needs to be high and it will be nearly vertical when it comes out to clear the radiator support.

The car or engine will be nearly vertical lol? I'm about to go work on it here in a while, I am planning on removing it tomorrow.

rs899 · #41 03-17-2009, 02:51 PM

I was talking about the engine. But if you can make the car vertical then the engine would come out horizontally....

MrGiggles · #42 03-18-2009, 12:18 PM

Well I got her ready to pull, waiting on my lift though. Gonna try for tomorrow after school.

How can I tell if the journals and crank are bad when I do get it out and apart?

bgkast · #43 03-18-2009, 02:12 PM

Quote:

Originally Posted by rs899

I was talking about the engine. But if you can make the car vertical then the engine would come out horizontally....

More like a 45* angle at most, maybe 30 if you put the back end on ramps.

rs899 · #44 03-18-2009, 04:02 PM

Just look for major scoring of the surfaces of the crank journals. They should be very smooth and polished if everything is normal.

mobetta · #45 03-18-2009, 09:28 PM

an engine balancer is a very nice tool to have on your hoist for these cars. the Tranny xmember nuts are clip on nuts-if you cant get them w/ a needle nosed Visegrip, cut the heads off the bolts- you will be able to get the rest out and replace them from a dealer.
I do think dropping the X member will make life easier.

dont forget the engine ground strap. you can lift the entire front of the car if that is still attached..........