Konstan's 1982 300D Engine Out Thread - Page 3 - PeachParts Mercedes-Benz Forum

vwkess · #31 03-12-2010, 08:00 AM

1-2mm of play?? Are you talking vertical or horizontal? If you are getting 1-2mm of vertical, that would definitely be a knockin!

konstan · #32 03-12-2010, 09:25 AM

horizontal...

vstech · #33 03-12-2010, 10:33 AM

yeah, you are going to have to pull the caps off.

vstech · #34 03-12-2010, 10:34 AM

how did the bottom of the pan look? anything in the sludge left in the bottom of the pan?

konstan · #35 03-12-2010, 11:26 AM

No particles in the pan... no sludge, either. The engine's been sitting upside down long enough, the pan was fairly clean on the inside.

So, I would like to write down my next steps and keep reading up on what I will be doing next.

Take the caps off -- is that what holds the connecting rod bearings together?
All of them or just #1?
What then?
I guess I am looking for something of an overview of what I am going to do to it over the next few days, so I have a near term goal in mind...

vstech · #36 03-12-2010, 11:29 AM

you can pull each cap off and inspect for severe scoring, or discoloration of the crank and look at the bearings for material wear, clean each bearing surface off, and put a section of plastigauge on there, and see if the tolerances are within specs. if it checks out, lube that bearing and move on to the next. check the crank bearings as well...

DeliveryValve · #37 03-12-2010, 11:52 AM

Also post pics of your bearing and crank surfaces.
Make sure you keep all debris out of those surfaces and keep it clean. The bearing surfaces are very soft and small debris can cause a deformation/small dents relatively easily in which may lead to issues down the road.

As far as the wrist pin is concern, while you have the cap off, you might be able to to check the vertical play while in the cylinder. While it's better/easier to check if it is out of the cylinder, this of course you would have to pull the head to get the piston out. There should be no detection of any play.

How's the cylinder's look at the bottom? You should see nice cross hatching? If not, then the cylinders are worn.

.

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jt20 · #38 03-12-2010, 01:45 PM

Quote:

Originally Posted by konstan

So, I would like to write down my next steps and keep reading up on what I will be doing next.

Take the caps off -- is that what holds the connecting rod bearings together?

I guess I am looking for something of an overview of what I am going to do to it over the next few days, so I have a near term goal in mind...

With no signs of traumatic wear in the bottom end, we are concerned that you may be chasing a ghost. 'Knocks' can result from many different things.

Currently, your goal should be to find evidence of a mechanical knock.

Before you go tearing the crank apart and mixing everything up, pull the head for further inspection. This will also allow you to free the chain from the lower end so you can work on it easier later.

konstan · #39 03-12-2010, 01:52 PM

Gonna go to HF and pick up a set of these:

konstan · #40 03-12-2010, 01:55 PM

I suppose as deep as I am into this thing, I won't be able to avoid pulling the head, right?

thorsen · #41 03-12-2010, 01:55 PM

Pick up some Plastigage while you are out. You use it to measure the bearing clearance.

http://www.ehow.com/how_2142943_use-plastigage-measure-clearances.html

jt20 · #42 03-12-2010, 02:05 PM

Quote:

Originally Posted by konstan

Gonna go to HF and pick up a set of these:

you mean this:

jt20 · #43 03-12-2010, 02:06 PM

Quote:

Originally Posted by konstan

I suppose as deep as I am into this thing, I won't be able to avoid pulling the head, right?

at this age, if it hasn't been done already, it should be mandatory to replace the head gasket.

I say go for it. it will provide another view of the engine's health.

konstan · #44 03-12-2010, 02:08 PM

For the head, yes, but for the caps won't I need the 'female' sockets?

jt20 · #45 03-12-2010, 02:12 PM

all they need is a 12-point metric socket. Not a specialty socket.