As Jim said, it is a straight forward job. There are, however, a few things to be aware of if you have not done one, or one like it before:

The chain tensioner is a ratcheting tensioner. You will have to reset it when you go back together. With the tensioner removed, push the plunger all the way through toward the engine and out, then START it back through before putting the tensioner in place. When you start the engine oil pressure will adjust it in position.

If you take out the camshaft, when you put it back in place get all your rocker arm assembly bolts started, but tighten them all a little bit at a time. If you tighten one pair of cam journal bolts all the way, you can break the camshaft. A little at a time all across, then a little more....

Make sure you measure the headbolt length and compare to the maximum length specified in the manual. If they are too long, get new ones.

When you torque the headbolts you will feel like you're going to twist them in half. Either mark each one after the initial torquing so that you know which ones you've turned 90 degrees or work the pattern for the 90 degree angle torque WITHOUT STOPPING. This is so that you don't get out of order or add 90 degrees to one that has already had 90.

For the M103 I find it easier to leave the intake manifold in place. On the M104 I think it's easier to leave it on the head and remove the whole thing. On the 103 you can get to some of the manifold bolts from underneath with a very long extension.

Be careful when installing the top timing cover. Use your fingernail to make sure the shaft seal does not fold as it goes over the end of the cam while you slide the cover STRAIGHT rearward. Use a slippery sealant on the U gasket below that cover.

Hope this helps.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

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