W140 S320 engine problem

[chefdeville]

My 1997 W140 S320 has now covered 68000 miles from new. In December I took it on a trip to the UK from the SW of France covering over 1000km.
It broke down on the M4. I thought it was the fan belt running p/s and water pump. It turned out that whatever holds the external crankshaft pulley in place had failed leaving the pulley free to eat the crankshaft shank.

It would seem the only permanent repair would be to remove the engine and replace the crank.

My question is: is this a common problem with this engine (which was widely used throughout the range of most M-Bs at that time?) I know I had it in an E Class convertible twenty years ago without issues.

If so, would it be likely to happen at such a (relatively) low mileage and should a service pick it up before it caused mainstream damage?

 

[ray_hennig]

whatever holds the external crankshaft pulley in place

If that is the M104 engine that sounds like the fan bracket bearing has failed. I have an M104 engine and the bearing failed en route from SW France to London. We heard noises when in the Loire valley. The fan was touching the water pump. This at about 250K Kms.

We made it to Wimbledon where Steve Redfearn fitted a new one. It's still in place at 1/2 million Kms but I have another in stock. Maybe I should replace it?

At your mileage that sounds pretty shoddy. It also sounds like a big bill. Sorry to hear that.

Good luck.

RayH

 

[W1ghty]

My 1997 W140 S320 has now covered 68000 miles from new. In December I took it on a trip to the UK from the SW of France covering over 1000km.
It broke down on the M4. I thought it was the fan belt running p/s and water pump. It turned out that whatever holds the external crankshaft pulley in place had failed leaving the pulley free to eat the crankshaft shank.

It would seem the only permanent repair would be to remove the engine and replace the crank.

My question is: is this a common problem with this engine (which was widely used throughout the range of most M-Bs at that time?) I know I had it in an E Class convertible twenty years ago without issues.

If so, would it be likely to happen at such a (relatively) low mileage and should a service pick it up before it caused mainstream damage?

What will that cost to repair ?
Might be cheaper to buy another car .

 

[chefdeville]

What will that cost to repair ?
Might be cheaper to buy another car .

I hate to think. I'm already on my second S320 W140. The last one was written off (and me nearly with it) having been forced off a small country road into a lower field by a kid driving in the middle of the road in the opposite direction fiddling with his telephone. Maybe I'm not destined to enjoy one for long!

 

[chefdeville]

If that is the M104 engine that sounds like the fan bracket bearing has failed. I have an M104 engine and the bearing failed en route from SW France to London. We heard noises when in the Loire valley. The fan was touching the water pump. This at about 250K Kms.

We made it to Wimbledon where Steve Redfearn fitted a new one. It's still in place at 1/2 million Kms but I have another in stock. Maybe I should replace it?

At your mileage that sounds pretty shoddy. It also sounds like a big bill. Sorry to hear that.

Good luck.

RayH

If that is the M104 engine that sounds like the fan bracket bearing has failed. I have an M104 engine and the bearing failed en route from SW France to London. We heard noises when in the Loire valley. The fan was touching the water pump. This at about 250K Kms.

We made it to Wimbledon where Steve Redfearn fitted a new one. It's still in place at 1/2 million Kms but I have another in stock. Maybe I should replace it?

At your mileage that sounds pretty shoddy. It also sounds like a big bill. Sorry to hear that.

Good luck.

RayH

Maybe these cars don't like being in SW France! Seriously, thanks for your advice about the bracket bearing. The strange thing is that when my car broke down it was sudden having done nearly 800km to Caen from the Lot where I live. The following day 90 mins or so out from Portsmouth and with no warning sound whatsoever, I suddenly just had a dashboard full of red lights!! So I assumed it was a fan belt! Nothing so simple!! Ben L

 

[Dodipops]

You get some good chemical metals nowadays, maybe worth a try putting a pulley on with some and see if it holds.

Not ideal granted but if it does work then I’ve just saved you thousands.

 

[carat 3.6]

It turned out that whatever holds the external crankshaft pulley in place had failed leaving the pulley free to eat the crankshaft shank.

It would seem the only permanent repair would be to remove the engine and replace the crank.

I've never seen an m104 crank pulley fall off the end of the crank, the only reason for that would be if it wasn't done up properly during a previous repair. The rubber inside the damper can disintegrate, but that wont damage the crank.

Unless the crank pulley is obviously detached from the engine, I'd seek another opinion. If it's just the keyway that has been damaged it can be repaired in situ without removing the engine.

 

[ray_hennig]

I'd seek another opinion.

Good point. Who is looking at the car now? And where is it?

I would try to get it recoverered to a good specialist recommended on this board.

R

 

[BlackC55]

That is very odd indeed. It might be best to get a S/H engine if you can't repair it.

 

[grober]

The second part of this video shows what you are dealing with----its over simplified !!! you really need a hd torque wrench and a way to lock the crank/ flywheel when removing and installing a new seal or crank key---but gives some visual clues to the parts involved.?

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