Timing Chain Tensioner (4.4)

[740ilDuke]

Just a note to help prolong your engine.

BMW redesigned the Timing Chain Tensioner from the original that dates
back pre X5 days. The new tensioner is much stronger and has a firmer spring and better overall design. The part is around $50 and simply threads in to the front of your 4.4 on the passenger side. I replaced the one in my 740il (4.4) this year and it was not doing anything helpful. The spring was shot and it was basically just in there doing nothing.

If you replace it, you will hear an ugly sound - which is normal - upon the first start up after replacement. The sound is the new tensioner aligning itself. The tensioner should reduce or eliminate rattle when you start the engine and reduce wear to the chain and guides by keeping it tight. If you've never replaced it, I would consider it. It's a small investment that could be the difference in how long your engine lasts. It's always the small things that make big impacts. I just bought one for the X5 today from this forum, and just wanted to share.