Question for anyone familiar with the OM612 sprinter 2.7 engine. 2004

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ChipChop

MB Enthusiast
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Newcastle
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S210 320cdi w201 190d 2.5
Went to view a prospective purchase today 2004 Sprinter 416 cdi and it ran fine (took a few seconds cranking to start though) but when i opened the oil filler cap, when the engine was off, the duplex timing chain had some slack in it. Is this normal?
 
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how much slack are we talking I'm sure if there was too much you would have heard it on start up,i used to work on these vehicles many moons ago when I was on the spanners and I have never heard of the chain being a problem unlike the end of the T1 about 94/95 era when they would stretch the chain, i would think there will be a little movement as the tensioner relies on oil pressure plus the chain is a series of linkages which all have movement in them
 
how much slack are we talking I'm sure if there was too much you would have heard it on start up,i used to work on these vehicles many moons ago when I was on the spanners and I have never heard of the chain being a problem unlike the end of the T1 about 94/95 era when they would stretch the chain, i would think there will be a little movement as the tensioner relies on oil pressure plus the chain is a series of linkages which all have movement in them
Sounds like i am worrying unduly then, just wanted to check if the timing chain should be tight when the engine is off. The engine has under 130,000 miles on it and ran perfectly with a rock solid idle, no funny noises and plenty of power on the test drive. Thanks for the info @jasons much appreciated.
 
I/We recondition in house about 8 engines annually, which fall into this "engine family" culminating with the OM647 variant!
Plus installing around 5 off "buy ins" totally recon units for faster customer turn around & shop times.

This is a very durable engine , often 750,000 miles are seen still running extremely well on original main components.
Just two things will kill it!
Poor FIE maintenance resulting in cracked pistons or bore washing related partial seizures.
I/We recommend injector removal & test @ 175,000 to 250,000 miles "tops" at a Bosch test centre for the 5 test parameters.

The other is bad or infrequent cooling system maintenance resulting in head gasket failures and cracked heads.

Now carbon/sludge is an Achilles heal to all chain drive engines , & the MB range is no exception. Since the engine doesn't have the need for low ash oils,. the unit thrives on Rotella T6 5w/40 full synthetic oil.
Change out is 10,000 miles
I have seen engines torn down at 500,000 miles and be totally "clean" inside run on that oil, & adhering to those MB service schedules

Chain wear at 130,000 miles would be minimal in most circumstances, & what you probably "felt " was side chain movement on the exhaust sprocket.
When I do a teardown, I always check the valve timing (if the engine will rotate--many don't, & that includes other brands we repair) in any case its important to a certain wear as a rebuild remedy procedure.
Certainly installing a new chain almost bottoms out the hydraulic tensioner, but I have reinstalled chains with similar mileages and had no timing issues nor conformity run outI
Checking the valve timing
This is easy to do on either an engine stand or in the frame.
In the frame with vacuum pump removed, you can roll the engine until the two half time pinions on each camshaft are meshed and the timing marks are adjacent @ 3 & 9 o'clock. positions . Then glance down to the crank timing mark and observe the OIE mark at the pointer.

This engine family is one of my favorite MB products, and as engines go being one of the BEST in its class
Tuercas Viejas
s





.
 
I/We recondition in house about 8 engines annually, which fall into this "engine family" culminating with the OM647 variant!
Plus installing around 5 off "buy ins" totally recon units for faster customer turn around & shop times.

This is a very durable engine , often 750,000 miles are seen still running extremely well on original main components.
Just two things will kill it!
Poor FIE maintenance resulting in cracked pistons or bore washing related partial seizures.
I/We recommend injector removal & test @ 175,000 to 250,000 miles "tops" at a Bosch test centre for the 5 test parameters.

The other is bad or infrequent cooling system maintenance resulting in head gasket failures and cracked heads.

Now carbon/sludge is an Achilles heal to all chain drive engines , & the MB range is no exception. Since the engine doesn't have the need for low ash oils,. the unit thrives on Rotella T6 5w/40 full synthetic oil.
Change out is 10,000 miles
I have seen engines torn down at 500,000 miles and be totally "clean" inside run on that oil, & adhering to those MB service schedules

Chain wear at 130,000 miles would be minimal in most circumstances, & what you probably "felt " was side chain movement on the exhaust sprocket.
When I do a teardown, I always check the valve timing (if the engine will rotate--many don't, & that includes other brands we repair) in any case its important to a certain wear as a rebuild remedy procedure.
Certainly installing a new chain almost bottoms out the hydraulic tensioner, but I have reinstalled chains with similar mileages and had no timing issues nor conformity run outI
Checking the valve timing
This is easy to do on either an engine stand or in the frame.
In the frame with vacuum pump removed, you can roll the engine until the two half time pinions on each camshaft are meshed and the timing marks are adjacent @ 3 & 9 o'clock. positions . Then glance down to the crank timing mark and observe the OIE mark at the pointer.

This engine family is one of my favorite MB products, and as engines go being one of the BEST in its class
Tuercas Viejas
s





.
Thanks @Tuercas viejas, your knowledge is much appreciated. Seemed like a lovely engine on the test drive, mated to the proper torque converter auto, which is rare in the UK, it was a pleasant test drive.
 
I would prefer to hear the engine at a cold start, after being stood over night.
While there is some extra noise on most and especially these as they 'settle' in there shouldn't be any chain rattle.
While I haven't experience on replacing the chain on these I don't imagine it's the same problem as with the 651 for example.

The slower start is usually down to air ingress, that's at any one of 6 or 7 cheap to buy 'o' rings. A common and easy fix. The fuel filter connection is often the culprit.

A greater concern will be vibrations. Being a Sprinter it's expected to haul a lot of weight. TC, auto box, engine mounts, gear box mount, prop shaft (I'm assuming rear wheel drive) can all become an issue. It's narrowing it down for remedy that's the pain.
Get it well warmed and look for vibes / hunting under load at around 1.8k - 2k revs, could be an early sign of auto box issues ahead.

Then there's rust.
 
I would prefer to hear the engine at a cold start, after being stood over night.
While there is some extra noise on most and especially these as they 'settle' in there shouldn't be any chain rattle.
While I haven't experience on replacing the chain on these I don't imagine it's the same problem as with the 651 for example.

The slower start is usually down to air ingress, that's at any one of 6 or 7 cheap to buy 'o' rings. A common and easy fix. The fuel filter connection is often the culprit.

A greater concern will be vibrations. Being a Sprinter it's expected to haul a lot of weight. TC, auto box, engine mounts, gear box mount, prop shaft (I'm assuming rear wheel drive) can all become an issue. It's narrowing it down for remedy that's the pain.
Get it well warmed and look for vibes / hunting under load at around 1.8k - 2k revs, could be an early sign of auto box issues ahead.

Then there's rust.
The current owner had recently changed the fuel filter so that may explain the slower starting. Thanks for your advice. Much appreciated.
 
Well now you are posting things of a wider picture.
So yes the fuel delivery system is akin the older big truck systems, and memories for me of repairing such Leylands, AEC's & Fodens up on the A40 in the Cotswolds with a DiamondT wrecker, before there was a motorway to London!
So maintenance is paramount to avoid drivability issues!
Of note, the plastic fuel delivery pipes go brittle with age and break/snap over time . Average life 175,.000 miles

The engine wiring harness is obsolete for all model derivatives , we are making new and mending in house.
Pistons are "tight" from Mahle & KolbenShmit as well , so are engine bearings, currently I have enough to rebuild three complete in house units, including new cylinder heads.

Basically the last of the infinitely repairable "old school" engines, and to cite examples , very high mileage units tend to fret away #2 main bearing cap.
Remedy! Simply select any old cap from a blown engine that fits snugly on the block register, then re-machine the crank tunnel to MB specs.
Bloody marvelous !

All later MB engines are not so, and join many other brand trends in having only limited re-work capabilities. These days its throw it away and buy new !
It would have prompted mechanics of my parent's generation (born 1920 to 1930's ) to label such newer renditions as Woolworth's diesels !
I back in the 60's that label was reserved for Ford/ Thames Traders & Bedford TK's. :D Times have changed.
Enjoy the van.
Tuercas viejas
 

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