Don't install your timing chain tensioner backwards....

[Olly84]

So I installed a new TC tensioner and did an oil change on my new to me 540it. the new tensioner came apart in the bag and I accidentally put it back together with the flat part towards the spring and the end with the nipple into the engine =X

Started her up and immediately there was timing chain rattle all throughout the rev range. For some reason my dumbass thought that the tensioner needed to be broken in or something so i drive it for about 2 miles to see if it'd go away. It didn't and it sounded like the failed timing chain guide noise (not the usual rattle at start up, but a constant rattling).

I'm thinking...did the new tensioner somehow accelerate failure since the old chain was used to the slack of the worn out tensioner?? I thought it was suppose to delay failure haha.

Decided to take a good look at the old tensioner I pulled out and realized that the flat part is what goes into the engine and nipple goes into the spring!!

Let the engine cool down, took out the new tensioner, disassembled it and reinstalled correctly and the noise went away completely. Engine runs a bit smoother and rattle on start doesn't occur as often.

So yeah, don't install the tensioner backwards.

[MIKYZZ4]

This reinforces my policy of,
slow and precise-beats quick and sloppy, everytime!!

[ruprectgern]

I think we've all had blank moments like that. I especially need to ensure that I get stuff done correctly, so I end up taking pictures every step of the way of all the parts and how they go together. I've been thinking about buying a garage camera so I don't have to keep cleaning my phone.
Also I tend to over-research the project and steps.

[MIKYZZ4]

Slowly and precisely just about guaranties a 100% success rate on a project,
that's my motto!

[Olly84]

agreed! Thought the tensioner was an easy mod and tried to rush through it before work! Started at 6am, had work at 8:30am. Thank god my appointment had to postpone so i had a few more hours to remedy the problem.

Slow and steady and blocking out the whole day works best for us diyers!

[RuskiE39]

This is why I triple check my triple checked work.