XSeries-forum

I decided to order the timing chain bottom tensioner just as a precautionary thing, anyway, it came without the washer/gasket so I'll be ordering via bmw.
I've read that these should come compressed and not to release them as you'll have a hard job fitting them, the one I've got is just in a plastic bag and is very easy to push in and out, am I missing something.

Morning
If you can push it in and out even though it is in it's bag it sounds as though it has been released, particularly as it has no sealing ring is the bag sealed?
The sealing/compression washers are easy to get I brought a box of assorted ones from Halfords years ago still got most in the garage.

Take out your old tensioner and check the length against your new one you will soon see if its triggered. If it has been it just makes the job more of a fiddle than it needs to be. Once changed I used to turn the engine over and turnoff before it fire's a few times to get some oil pressure before starting.
I don't have to do that anymore having fitted a pre-oiling system after my engine rebuild.

It came in a sealed bag in a box, it's a febi version.
What actually stops them from being released, it just looks like a piston that is triggered by oil pressure.

That is exactly what it is the piston is spring assisted, when new the spring is supposed to supply enough pressure to the chain guides in the nano seconds prior to oil pressure building up.
Unfortunately with a number of heat cycles the spring anneals and softens allowing a little slap at start up which in turn accelerates wear on the plastic guides. The guides also subject to the heat cycles harden and become brittle, they then start to disintegrate. Been there suffered that, so after engine rebuild and to help I fitted a pre-oiling system that gives instant oil pressure as soon as the key is turned.
The piston is held by a small ridge that holds on the seal seems to only work once when they assemble it? Febi I believe were one of the OEM suppliers.

Finally fitted this today, not a bad job really, even with my shovel hands, but boy was it tight.

Yay Fiddly job more than difficult