Help?????Om642 front main bearing tick after service.

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Magnaman

New Member
Joined
Aug 25, 2017
Messages
9
Location
Oxfordshire
Car
ML320 Cdi
Have had my w163 320cdi serviced and now has a ticking sound coming from engine. MB has confirmed issue.

Anyone here replaced the bearing and can it be done with engine still in place?
Also has anyone had to pay to have this done and how much would it be?

Thanks
 
Main bearings need the engine out and stripped in order to change them, never heard of a main bearing ticking. Mains tend to rumble and big ends knock.
 
Yes sounds like a major mis-diagnosis to me!
Suggest running it for a static test without the accessory belt installed.
Tuercas viejas
 
As what post #3 says (Tuercas viejas). The ticking should stop with the belt removed if it is the main bearing. MB bulletin recommends using their jig to hold the engine in place allowing removal of the gearbox / front cross member to get at the underside of the sump. The bearing can be replaced with an updated version without removing the crankshaft.
You need to be talking to a garage who has done this before as I spoke to a whole bunch of "MB specialists" before finding the right garage for this job - They also had never done it before but were willing to research with the local MB main dealer before committing. My car was stuck on one of their ramps for an entire week whilst waiting on the specific tolerance bearing to arrive from Germany.
 
As what post #3 says (Tuercas viejas). The ticking should stop with the belt removed if it is the main bearing. MB bulletin recommends using their jig to hold the engine in place allowing removal of the gearbox / front cross member to get at the underside of the sump. The bearing can be replaced with an updated version without removing the crankshaft.
You need to be talking to a garage who has done this before as I spoke to a whole bunch of "MB specialists" before finding the right garage for this job - They also had never done it before but were willing to research with the local MB main dealer before committing. My car was stuck on one of their ramps for an entire week whilst waiting on the specific tolerance bearing to arrive from Germany.
Phew ! I bet you were Mr Popular after tying up a ramp for a whole week !
 
Phew ! I bet you were Mr Popular after tying up a ramp for a whole week !

They weren't thrilled but were expecting a wait as they had researched the job and could only identify the correct bearing after starting the job. The bearing shells were not held in UK stock. The bearing shells cost very little but the labour is significant but can be minimised by following the MB repair procedure. Most of the "specialist's" I spoke to wanted to fully rebuild my low mileage, well serviced engine. Some were pretty ignorant and did not want to discuss anything other than a full rebuild. My engine has been perfect since the repair a couple of years ago.
Apparently quite a few of these failures were covered by MBUK under warranty but I would bet there are a bunch of OM642's running about with this issue.
A great idea is to fill the oil filter housing during oil changes before starting the engine.......
 
Hi all, V Belt removed and noise can't be heard. Have had a lot of mechanics including current MB technicians. Only one has said main bearing 1....the rest have said power steering pump and pulley as there's excess play in it.
Any body know the cost of parts and labour for this job?
Original post correction.....engine is an Om642 for a w164 ML320.
 
Hi all, V Belt removed and noise can't be heard. Have had a lot of mechanics including current MB technicians. Only one has said main bearing 1....the rest have said power steering pump and pulley as there's excess play in it.
Any body know the cost of parts and labour for this job?
Original post correction.....engine is an Om642 for a w164 ML320.

That's more like it!
I use a set of mini transmitters applied to various select areas of the engine called "chassis ears"!
These will detect each noise from the components you are testing.
No self respecting shop should be without a set of these.
Chassis Ears
https://www.amazon.com/dp/B00123J79O/
Tuercas Viejas
 
Hi all, V Belt removed and noise can't be heard. Have had a lot of mechanics including current MB technicians. Only one has said main bearing 1....the rest have said power steering pump and pulley as there's excess play in it.
Any body know the cost of parts and labour for this job?
Original post correction.....engine is an Om642 for a w164 ML320.

Parts and labour for a bearing crank shell change out--you will need deep pockets.
Budget about 32 hours labour.
First the engine has to come out because the pan and rear main seal plate are attached to one another behind the flywheel/ flex plate plus a few location fixing screws.
With that out of the way you can pull down the windage tray and oil pump arr! to expose the crank caps and rod big ends.

Some crankcase exterior accessories at that point will need to be removed to extract the main bearing cap flank girdle retention bolts.

As a side bar MB does not make U/S shells available for this engine!
There are however selectable O/S shells in 7 sizes 0,001mm up , going by colour codes to fit the shell to the crank tunnel on production. This accounts for machining tolerances during production line machining/line boring of the crank tunnel.
To get accurate seating and shell "nip" in the tunnel I have had to resort to engineer's blue paste to gauge shell seating patterns

Frankly if you get a lower end failure on this engine recovery is doubtful due to the lack of available regular service U/S & O/S parts . In any case finding a crankshaft repair shop willing to resurface a split throw cronk as you find on this engine is rare these days !

In my apprenticeship days of the 1960's this engine would be dubbed a Woolworths diesel by the old sweats I apprenticed under.
A term mostly reserved for Thames Trader and 300 Bedford TK engines with tin pot cylinder liners and of course (must mention) the 5,9 BMC diesel the eternal crank buster and block twister.
All these "wonderful" engines worked very well but once they were done--- they were DONE --New engine required!
Lets hope you haven't spun a bearing
Tuerca viejas
 
notsofast said:
They weren't thrilled but were expecting a wait as they had researched the job and could only identify the correct bearing after starting the job. The bearing shells were not held in UK stock. The bearing shells cost very little but the labour is significant but can be minimised by following the MB repair procedure. Most of the "specialist's" I spoke to wanted to fully rebuild my low mileage, well serviced engine. Some were pretty ignorant and did not want to discuss anything other than a full rebuild. My engine has been perfect since the repair a couple of years ago. Apparently quite a few of these failures were covered by MBUK under warranty but I would bet there are a bunch of OM642's running about with this issue. A great idea is to fill the oil filter housing during oil changes before starting the engine.......
hi not so fast
Who did you use and what was the cost? Thanks.
 
hi not so fast
Who did you use and what was the cost? Thanks.

I am in the NE Scotland. My car was repaired by Moray Firth Motors in Inverness. I am still a few hours away from them but it was worth the effort. I do not recall the exact cost but it was something like £1100 or 1200 including parts but the understanding was that the responsibility / liability on diagnosis remained with me.
The must change parts are the bearing shell and sump as the sump cannot be removed without distorting it. Recommended to change are also the bearing cap bolts and the rear crankshaft seal (I did not have mine changed due to low mileage and being a tight Scotsman). You obviously also need to replace the oil.
The quotes I had at the time from most other "specialists" were £3000 up to £5000 "depending on what else needed done".......
In my case, the ticking noise is fairly distinctive, not constant (misses now and again), engine temperature made no difference and I was pretty confident the fault was exactly as defined in the MB bulletin (link attached in the post above).
 
What vehicle please? Have been told also wrong oil can also cause tapping noises
 
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I am in the NE Scotland. My car was repaired by Moray Firth Motors in Inverness. I am still a few hours away from them but it was worth the effort. I do not recall the exact cost but it was something like £1100 or 1200 including parts but the understanding was that the responsibility / liability on diagnosis remained with me.
The must change parts are the bearing shell and sump as the sump cannot be removed without distorting it. Recommended to change are also the bearing cap bolts and the rear crankshaft seal (I did not have mine changed due to low mileage and being a tight Scotsman). You obviously also need to replace the oil.
The quotes I had at the time from most other "specialists" were £3000 up to £5000 "depending on what else needed done".......
In my case, the ticking noise is fairly distinctive, not constant (misses now and again), engine temperature made no difference and I was pretty confident the fault was exactly as defined in the MB bulletin (link attached in the post above).
Hi, thanks very much for coming back to me. Had listened to your video and I can hear a rumbling knocking noise also. Mine only ticks (same as in your video) but no other noises.
Waiting for MB to come back with price, have also had one Indi not wanting the job.

So your engine and gearbox stayed in the car? But sump was distorted to get the the front bearing yes?
 
Hi, thanks very much for coming back to me. Had listened to your video and I can hear a rumbling knocking noise also. Mine only ticks (same as in your video) but no other noises.
Waiting for MB to come back with price, have also had one Indi not wanting the job.

So your engine and gearbox stayed in the car? But sump was distorted to get the the front bearing yes?

It is the regular ticking you are listening for. The engine is supported in place on a jig. The gearbox needs to come out to give access to the rear crankshaft seal housing which needs to be removed in turn to allow the sump to be removed. The sump is very thin and well sealed with RTV hence twists when removed. Not particularly expensive from memory but more than the bearing shells. The front suspension crossmember is also dropped from the car complete with suspension and wheels as it prevents access to the sump. The crossmember also has the engine mounts hence the need for the engine support jig.
I guess the time taken to remove the crossmember is less than disconnecting all the engine connections and ancillaries' (Exhausts, A/C, fuel lines, coolant hoses and a myriad wiring etc). Also much less likelihood of further induced problems after the rebuild also as the access to remove the crossmember is good where as access to the engine is not so great.
Once the sump is off, the oil pump blocks access to the crankshaft bearing cap so is removed also.
The MB procedure linked in my earlier post details the sequence of strip down.
 
I would get another check on it first .
The cam followers are critical to what oil is used. . If oil of the wrong type is used then the cam gear and followers wont get enough lubrication thus the tick tick .Its hard to say without looking at the engine .Some say a tick others say its a knock . Ticking will come from the valve cover .Knocking will come from the engine block .Remove oil filler cap and see if noise changes ,if so then its top end problem and not crankshaft bigends
 
^^^^^^^as above...

I have dealt with motors all my driving life 53yrs for my hobby stripping engines getting rebored etc.etc. and i have never ever heard of anything so stupid as this cracklin` tick?

Why wait all these years of development in efficient modern engines and a high class manufacturer such as MB to make such a blunder also in an engine that did the worlds endurance record of 100,000mls?

I do believe the ways of making money have really gone too far!....even if MB do have a bulletin!

Nobody can be trusted these days in whatever we purchase.

Just think about how heavy the reciprocating parts are and together with oil pressure how can one hear a tick from the main or big ends?....you hear a heavy knock on idle for big ends and a rumble only when driving for mains worn.
 
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I am in the NE Scotland. My car was repaired by Moray Firth Motors in Inverness. I am still a few hours away from them but it was worth the effort. I do not recall the exact cost but it was something like £1100 or 1200 including parts but the understanding was that the responsibility / liability on diagnosis remained with me.
The must change parts are the bearing shell and sump as the sump cannot be removed without distorting it. Recommended to change are also the bearing cap bolts and the rear crankshaft seal (I did not have mine changed due to low mileage and being a tight Scotsman). You obviously also need to replace the oil.
The quotes I had at the time from most other "specialists" were £3000 up to £5000 "depending on what else needed done".......
In my case, the ticking noise is fairly distinctive, not constant (misses now and again), engine temperature made no difference and I was pretty confident the fault was exactly as defined in the MB bulletin (link attached in the post above).

For about 1200 quid you got a steal!
The labor charge alone would be at least three times that so someone subsidized something somewhere!
Or someone worked for nowt !
Remember the mantra Pay peanut and you often get monkeys!

Even doing in frame method (fraught with possible expensive mistakes) leaves the shop open to possible repeat failures down the road.

Take into account that at the end of the main oil gallery is an oiler tube with a series of fine #15 holes drilled into it like a flute. This creates a fixed oil pressure loss over the tube and is used for chain oiling spray.
Prone to being torn off by timing chain "let go" or, even whacked/rubbed through by a slack chain it renders the block as scrap!

Why you might ask?
Well the oiler tube has a snap ring groove machined around it where it locates into the block! That round section snap ring expands and locates into a parent grove in the block boss when hammered in on production . Now being locked into position it cannot be removed without damage! In fact if it gets whacked by the chain it often breaks the boss casting causing excessive oil pressure loss and front bearing/journal failure.
In many cases from my experiences the shells weld themselves to the crank crank journal and spin in the tunnel tearing up the parent seating the block being rendered scrap.....
For all these very reasons simply going in and replacing a shell "willy nilly" without cautionary activities can be-asking for big expensive latter repairs.
In any case why struggle with the frame method" when with a "engine pull" in a far better approach? (gotta think smart)
The unit can be fully examined and remedial action taken where necessary (again think smart) other wise its another possible Dunkirk screw up and we all know how that turned out! Know the risks and exculpatory remedies
Tuercas viejas l
 
Yup - you pay your money and make a choice. I hope it works out for the OP.
 

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