Ultimate OM642 build (2009 R320L CDI, 7G-Tronic)

[LostKiwi]

This series will help give you an idea. You will need to know specific measurements and specs for your engine. Use this as a guide only!

 

[M80]

A final cost will be interesting.
Keep up the good photo's

 

[Ge2tis]

A final cost will be interesting.
Keep up the good photo's

When it's all done, I will post everything that went into rebuild...
Trying my best..

 

[LostKiwi]

When it's all done, I will post everything that went into rebuild...
Trying my best..

All credit for giving it a go.
If you don't understand then ask. I and others will try to help as much as we can.

 

[Ge2tis]

Right, update time...
Not much has happened recently, but I thought I will give you the heads up..
So, I got the heads back...all look as new...should perform as well..
The crankshaft turned out to be in as good nick as I was hoping..no cracks and no warping...also the surface of the journals is pretty much spotless...both CNC machinists and my engineer confirmed that...so happy days...
Engine block has also been taken to an engineer who gave it a good check up and honed the bores...nothing to worry about as well...
I've started cleaning everything with some white spirit and WD40 and a lot of elbow grease...not finished yet though...
So that's about it...
On the other hand I have a few questions, maybe someone could enlighten me please:
1. As MB has a few sets of different thickness main and big end bearings even for STD sizes, what's the best way to determine which ones to choose for the correct clearance? I was thinking as follows: measure the main bearing bore size with the cap screwed on (does it require to be torqued to spec?) minus the measured crankshaft main bearing journal size then minus the clearance required (should I go min, Max or average?), and then divide it in half which technically should give the required thickness of the bearing cap required...I hope I make sense..
2. Where about on the piston it's best to take the measurements to check for piston to bore clearance? Could not find it anywhere on WIS.

Also, how on earth does this engine survive on 0.3 Bar of pressure at idle it's still a mystery to me...

A few pages from WIS attached...

 

[LostKiwi]

Looking at that you need to measure the crank journal diameters and compare to the table values. That will then tell you the colour of shell required. Always measure the journals in line with the throw of the crank and at 90 degrees to the throw of the crank. You don't want any ovality of the journal.
To check the clearance of the crank to shell use plastigage.

To measure piston clearance use a set of feeler gauges between the skirt and bore.

 

[Ge2tis]

Hello again everyone....it's been a long pause here on this thread and meanwhile a few things happened:
First of....the engine is complete!!!!! Yaaaayyyyy!!!!! However it took me much much much more than anticipated and what must have been done before Christmas ended up being before Easter..
I took a few photos of the build and will be putting all of them to this thread later on, however now I have a question...when started the engine makes a ticking/knocking noise that I know shouldn't be there, any ideas what that might be...???
Video links:
Warm engine...

Cold engine...

 

[Wighty]

Welcome back , I've been waiting for the update . Some fantastic work there . Is that a catch tank you have installed with the 2 zip tied pipes crossing the engine ?

 

[EXMERCTECH]

Bit late but the journal diameter is stamped on the block and crank nose.
With a series of digits numbers.
Block denotes main journal crank will be crank journal size.
These then need to be matched with the Mercedes EPC to determine which shells you need.
Note
You may find they are not all the same size.

Question.
Is the Cylinder bores plated on these engines.
( Haven't got my 642 Training manuals to hand)
New Chain and tensioner fitted and timed correctly?.
Injectors tested?.
Have you replaced the injectors back in there original places or recoded to new cylinders.
Hydraulic Tappets new old?.


What's the two black hoses on the engine.
Guessing oil catch tank?.

 

[Ge2tis]

Welcome back , I've been waiting for the update . Some fantastic work there . Is that a catch tank you have installed with the 2 zip tied pipes crossing the engine ?

Yes, it's the oil catch can, Provent 200...it's fitted under front N/S headlight as that's the only place where I could fit it...

 

[Ge2tis]

Bit late but the journal diameter is stamped on the block and crank nose.
With a series of digits numbers.
Block denotes main journal crank will be crank journal size.
These then need to be matched with the Mercedes EPC to determine which shells you need.
Note
You may find they are not all the same size.

Question.
Is the Cylinder bores plated on these engines.
( Haven't got my 642 Training manuals to hand)
New Chain and tensioner fitted and timed correctly?.
Injectors tested?.
Have you replaced the injectors back in there original places or recoded to new cylinders.
Hydraulic Tappets new old?.


What's the two black hoses on the engine.
Guessing oil catch tank?.

I measured the journals with bore gauge and then double checked with plastigauge to confirm the clearances and yes, not all are the same...

Chain and tensioners all new, timed by the WIS instructions...
Injectors tested and put back to their own placed, not mixed. The workshop who tested them said they are not great but far from being faulty...they have 180k so I didn't expect them to be like new...
Tappets though are old...I kept them soaked in engine oil all the time when removed...
Hoses are oil catch can...

 

[snoman]

This ticking sound has often been heard on Chrysler CRDs with the same engine. I even noticed it on a brand new demonstrator, back in 2006. The sales guy was also aware, but he said the workshop couldn't find anything wrong. Thankfully, the new car I purchased was noise free and has been ever since. However, Chrysler were aware of the problem and issued a TSB to correct the problem. More details in this post from a Jeep forum: http://www.jeepforum.com/forum/f67/ticking-noise-tsb-wk-crd-2984081/

 

[Ge2tis]

This ticking sound has often been heard on Chrysler CRDs with the same engine. I even noticed it on a brand new demonstrator, back in 2006. The sales guy was also aware, but he said the workshop couldn't find anything wrong. Thankfully, the new car I purchased was noise free and has been ever since. However, Chrysler were aware of the problem and issued a TSB to correct the problem. More details in this post from a Jeep forum: http://www.jeepforum.com/forum/f67/ticking-noise-tsb-wk-crd-2984081/

That's an interesting read...and sort of gets my mind at ease a bit...I shall keep an eye on it and hope for the best..
From my understanding when oil is changed it drains too much if that's even possible and before the oil pump can supply the pressurised oil to all galleries the tappets or cams run dryer than they should and here comes the noise...correct me if I don't make sense..

 

[snoman]

I'm not convinced about your theory of oil draining too much. I haven't noticed any ticking noise following an oil change. I assume you are using the MB specified oil? Also, oil should still be clinging to the moving parts, even after draining. Perhaps following the major (and impressive) re-con you have undertaken, you need to allow a bit more time for things to settle. In any event, a little ticking doesn't seem to be serious, although it can be annoying.

I've just realised, having listened to your engine recordings, that I may not be comparing like with like. The Chrysler 300C CRD engine is exceptionally quiet with engine covers in place and bonnet closed. From inside the well insulated cabin you could be forgiven for thinking that the engine was a petrol - unless the aforementioned ticking was present.

 

[notsofast]

I had the main bearing go out on my OM642. The bearing was replaced and the engine has been quiet since. I always make sure the oil filter housing is filled with oil when changing out the filter now......
Previous post - http://forums.mercedesclub.org.uk/index.php?threads/experienced-ear-needed-for-om642-tapping.144326/

 

[snoman]

I always make sure the oil filter housing is filled with oil when changing out the filter now......

Is this "official" MB procedure? Is this what dealerships do? I've never done this on my 300C, or for that matter, any other car I have owned. In fact, on the 300C, I always completely remove any old oil from the filter bowl using my Pela pump. Some car engines have the filter bowls installed horizontally, which would make pre-filling difficult.

 

[Ge2tis]

Thanks guys for all the input. Well, I shall see how it all goes for a while..I don't mind the ticking noise as long as it's not damaging the engine..if it changes in any way then I will have to deal with that..I've replaced the oil first time already (initial brake-in of around 20 miles) and didn't see any kind of debris in the filter or oil for that matter...next oil change in 1000 miles...

 

[bembo449]

do these have the oil filled buckets on the rocker / tappet set up ?

 

[Ge2tis]

do these have the oil filled buckets on the rocker / tappet set up ?

No, they don't. It has hydraulic tappets and rocker arms that you see in pic. No buckets.

 

[bembo449]

ok , on engines ive rebuilt in the past , ive had to squeeze the old oil out of them so they refill with fresh , it prevents them from ticking