E60: Engine Rebuild 1

This was complicated, but a totally realistic DIY job if you have the time. It is a lot easier than it has to be by 3 factors:

1. No need to remove the front-bumper, radiator, aux. belt and pulleys as chain is not replaced.
2. No need to fully retime as lower tensioner keeps chain on lower cog even though upper-cog is removed, pump chain is separate.
3. Obtaining a 17mm allen-key type socket to undo a front-plug and access the chain-tensioner. This is actually the only 'special tool' you need.

Hand-ground pistons and block get a final clean before new gasket is put on.

Recon head from a twin-turbo X6 diesel mates up with new Febi head-bolts and crazy torquing sequence.

Once the front plug (where the allen-key is sticking out under the belt) is removed with a 17mm male-hex (allen-key type) socket, the tensioner can be accessed. A 10mm nut below the tensioner is released to free oil-pressure, then the plunger can be pushed all the way back and a pin inserted to hold it in place - the 3mm allen-key in the picture worked for me. The oil-pressure nut is retightened after the chain is back on and the tensioner released.

Unable to turn the engine, camshafts had to be positioned by eye based on photos of before the chain was removed.

Nice dollop of fresh oil on the rockers / guides / bearings and caps.

Rocker-cover is the most involved part of the job as all the injectors / fuel pipes plumb into it.