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Discussion Starter #1
Hi There Again
Newbee question. Does the subject line engine have a belt or chain and how often should it be changed and with what associated parts? Bearings, seals etc. Again this is my first Mercedes Diesel. I beleive it has a belt. Do not have the auto or manual yet. What approx is the cost for the items and time required for install.

ThankYou
Calvin
 

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The Engine has a Timing Chain.
As far as the Chain itself goes I have not read of a specific milage interval to change it or the associated parts.
You can get some idea of how much the Timing Chain has Stretched by removing the Valve Cover and lining up the Camshaft Sprocket Timing Mark with the Timing mark on the Bearing Cap. You need to do this as exactly as possible.
After that you look at your Crankshaft Damper to see what degree marks the Pointer is pointed at.
When the Engine was built it lined up at Zero Degrees (this is Top Dead Center on the #1 Cylinder).
You will have to consult a manual to see if there is a more accurate method to check the Timing Chain Stretch. On the Older Models there is such a method.
However, how much is too much Stretch? On the Older Models Mercedes recommends on specific interval for changing the Timing Chain. I would call a couple of different Dealers and get their opinion.
For myself if I had a Chain that was showing more than 6 Degrees or more with the accurate method in the Service Manual I would change mine.
Clean Oil has a best effect on Timing Chain life.
Change seals when they leak bad enough.
I have read of no preventative maint. concerning when to change Bearings.

If you Vacuum Pump gets noisy stop driving the Car until it is replaced. The reason is that the parts can break off and fall into the Timing Chain/Gears and after that there is a good chance of severe Engine Damage.
 

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I forgot to mention. Not on your model but on my model the parts alone to replace the Timing Chain are about $250; That is the Chain at $150 + some of the Tensioner Rails (this is not replacing any of the Sprockets).
Labor depending on where you are could easily be in the $300-$500 or ?
 

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Discussion Starter #4
I have changed Timing belts in by Alfa Romeo 164 before and it was a hell of a job due to working through the wheel well. Since this is a Diesel I imagine the compression to line up timing marks would be hard to manage since there are no spark plugs to remove to release the compression.
 

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Actually rotating the Engine against the comopression is not as big of an issue as you might think.
On my model it can be done by using a wrench on the Power Steering Pump and using the belt tensioner to tighten up the V-belt.

The other way is to use a Socket on the large Crankshaft Damper Retaining Bolt. (On mine you have to rotate the Engine to adjust the Valves so I know it can be done without too much problem.)

The last way is to use a Remote Starter Button and use the Battery to bump the Engine until you get close to where you want and turn the Engine by hand the rest of the way. On my model there is an easy to get at Wire Terminal Block where you can hook the Remote Starter Up.

At least one of the above methods can be used on your car.
You need to read the Factory Service Manual for what the way Mercedes recommends turning the Engine.
Always turn the Engine in the direction of normal rotation. If you go past were you wanted to be you have to continue to turn in the direction of rotation until that point comes up again.

On Diesel Engines the Injectors can be removed and that will relieve the Compression and your Engine also has Glow Plugs that can be removed and removing them will also relieve Compression.
However, if your model of Engine has an Aluminum Cylinder head it is not uncommon for the Hex Head on the Glow Plugs to break off when attempting to remove a Glow Plug.

There are some metnods of decreasing the chance of them breaking off. However, too much detail for me to go into right now.

I also forgot to mention that the Tool to put the proper Crimp on the Timing Chain is around $250 (sold on eBay). You get the Chain and a Master Link. Ounce the Master Link is on you need to use the tool to crimp (mush) over the ends of the master link so it is rivited together.
Due to the expense of the parts and the tools involved it is best to check the Timing Chain Stretch and not Change the Timing Chain unless it is worn.
 
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