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It's about £65 plus vat. It didn't make much difference on my 92 M5T with 60 000 miles, but then it was no more noisy at start than when warm. The swap is not difficult, you need a deep, thin walled 32 mm socket for the swap. If you ever do remove the old tensioner is MUCH easier to install the new tensioner than putting the old design one back in.

Regards

Alex
 

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Frank,

I have replaced my tensioner with the item from the S50B32 myselfe.

Note that the S38B36 chain tensioner is different then the iem for the S38B38, which is the same as the one used on the S50B30 engine. On the S38B36, an oil-accumulator (diaphragm) is bolted onto the tensioner itself. This helps the tensioner being effictive directky after at cold-start-up when all the oil still is in sump. However, this 'complexity' adds two additional seals and thus two more sources for leaking. Also the diaphragm itselfe could come loose over time making matters worse. When I removed the diaphragm on my car, it was already loose and rather contaminated with oil as can be seen on dsc02963.jpg (attached)

Picture dcs03008.jpg shows the internal parts of the S38B36 and the S50B32 chain tensioner. Picture dsc03013.jpg shows the S50B32 tenioner installed on my S38B36.

Removing the old tensioner is rather easy, but you can't reach it without removing some parts. From underneath, the A/C pmp and the O2 pum sits in teh way and from above, one needs to remove the 'windscreen-flui reservoir'.
One needs a 17mm hex socket to remove the bolt that holds the diaphragm (3.6 only) and the tensioner-socket (both 3.6 and 3.8). The spring comes loose after which you can remove the tensioner-plug. Then, remove the tensioner-socket with a 32mm socket.

Reinstalling the S50B32 tensioner is a bit more tricky as you have to make sure that the pug is properly alligned and stays alligned. This is a bit difficult as the plug slides back when the 32mm socket (with seal!!!!) is installed. I solved this by adding a bit of Castrol TWS 10W60 in the socket to prevent the plug from falling back. Finally, Torque the socket with 55nm and you are ready to go.

One important note: With the tensioner out, it is not impossible that the chain skips a tooth or two. Two tooths is a big 'no-no'. If your chain is OK, the replacement of the tesnioner should not cause any other problems, but when the chain lenth has increased, be very wary to do this. Then I'd rather replace the chain, guides ect. Checking the chain-length is a different story though

With the S50B32 tensioner, I noticed my car is much more silent after cold start. It also 'spins' much more so it was well worth the effort.
 

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Raymond, the tensioner in my S38B38 looked exactly like your old one. I think the S38B36 and S38B38 share the same original tensioner. Anyhow I think the S52 tensioner is a good upgrade for both engines.


Regards
Alex



"Note that the S38B36 chain tensioner is different then the iem for the S38B38, which is the same as the one used on the S50B30 engine. On the S38B36, an oil-accumulator (diaphragm) is bolted onto the tensioner itself. This helps the tensioner being effictive directky after at cold-start-up when all the oil still is in sump. However, this 'complexity' adds two additional seals and thus two more sources for leaking. Also the diaphragm itselfe could come loose over time making matters worse. When I removed the diaphragm on my car, it was already loose and rather contaminated with oil as can be seen on dsc02963.jpg (attached)"
 

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I haven't had any noise on the M5 but the same upgrade applies to the S14 in the M3. I had this done during a routine service and it made a big difference. I have found that quite a number of parts are "shared" between the two engines.
 

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Guys, thanks for the feedback - especially Raymond a veritable M5 Meister.

Will get a quote from the Bexley boys as I'm due a service anyway - if it doesnt cost me an arm and a leg its a goer.

Frank
 

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Frank,

I have replaced my tensioner with the item from the S50B32 myselfe.

Note that the S38B36 chain tensioner is different then the iem for the S38B38, which is the same as the one used on the S50B30 engine. On the S38B36, an oil-accumulator (diaphragm) is bolted onto the tensioner itself. This helps the tensioner being effictive directky after at cold-start-up when all the oil still is in sump. However, this 'complexity' adds two additional seals and thus two more sources for leaking. Also the diaphragm itselfe could come loose over time making matters worse. When I removed the diaphragm on my car, it was already loose and rather contaminated with oil as can be seen on dsc02963.jpg (attached)

Picture dcs03008.jpg shows the internal parts of the S38B36 and the S50B32 chain tensioner. Picture dsc03013.jpg shows the S50B32 tenioner installed on my S38B36.

Removing the old tensioner is rather easy, but you can't reach it without removing some parts. From underneath, the A/C pmp and the O2 pum sits in teh way and from above, one needs to remove the 'windscreen-flui reservoir'.
One needs a 17mm hex socket to remove the bolt that holds the diaphragm (3.6 only) and the tensioner-socket (both 3.6 and 3.8). The spring comes loose after which you can remove the tensioner-plug. Then, remove the tensioner-socket with a 32mm socket.

Reinstalling the S50B32 tensioner is a bit more tricky as you have to make sure that the pug is properly alligned and stays alligned. This is a bit difficult as the plug slides back when the 32mm socket (with seal!!!!) is installed. I solved this by adding a bit of Castrol TWS 10W60 in the socket to prevent the plug from falling back. Finally, Torque the socket with 55nm and you are ready to go.

One important note: With the tensioner out, it is not impossible that the chain skips a tooth or two. Two tooths is a big 'no-no'. If your chain is OK, the replacement of the tesnioner should not cause any other problems, but when the chain lenth has increased, be very wary to do this. Then I'd rather replace the chain, guides ect. Checking the chain-length is a different story though

With the S50B32 tensioner, I noticed my car is much more silent after cold start. It also 'spins' much more so it was well worth the effort.
I'd like to get some opinions as to what is the risk of the chain skipping a tooth or two. My car has 178k miles and I don't see that the chain has been replaced in the PO's receipts. He had owned the car from 1996 until last year.
 

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Skipping any teeth is a big no no. Bad things happen.

I know A LOT of people do this, on S14's also, but I have one problem with the S50/S52 tensioner...it applies TOO much tension and causes increased wear on the soft (or hard and brittle if they are old) & expensive timing rails these engines have. If your trying to do preventive maintenance then this would be going in the wrong direction as its just going to increase wear. Ever look at a chain rail...they are always grooved. Think adding more tension to that is better?

I would suggest the E32 V12 tensioner as it applies slightly more tension then the stock one does but not as much as the S50/S52 variant, and I would only use it on new timing rails.
 
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