[jhall0711]

Good morning all; first post here as I have been reading and did a lot of lurking here prior to purchasing my car. Last week I picked up a 2015 428XI that I am super excited to have.

I have ordered and am planning to replace my timing chain tensioner. I know there is some debate on if that is something to do as "maintenance" or not, but in my mind they updated the part; so something is obviously different. So I plan to change it.

My question is; I have read at lease one post where when the old tensioner was removed, the engine timing changed (can't recall if this was here or another forum) but it had me wanting to confirm. The actual BMW tech manual says nothing about needing to remove valve cover lock cams ETC, when replacing a tensioner but wanted some real world feed back on if there is a risk.

Plain and simple; can anyone confirm for me that the timing and everything will stay in position if the only thing I do is remove the tension and replace it with a new one?

Thanks so much.

[GreenF30N26]

I replaced my tensioner yesterday by just removing the tensioner and reinstalling the new one. Now, after I did it I read on FCP euro you're not supposed to release the tension on the rail. So now I'm paranoid, but the car runs fine and the chain didn't jump. But I did go to punch it and the car delayed going for a second or so longer than what I deem normal. Only happened once though. Could be the timing is messed up now. Another member put tension on their chain through the filter to ensure the chain didn't move.

FCP Euro says
"Remove the timing chain tensioner tool, but don't release all of the tension from the rail. Having a partner handy will help make this process easier. Also, have the new tensioner within reach once the tool is removed.

Grab a set of channellocks and grip the knurled part of the tensioner. Turn it toward the back of the engine to loosen it enough to spin it with your fingers. As you thread the tool out, watch the chain guide move. When it starts to move, put one hand in the engine to keep the pressure on the rail as you back out the tensioner tool with the other. "

[jhall0711]

So that was actually my thought as well; reaching through the oil fill hole in some manner to hold it in place while it is removed.

Could you share the FCP link you read please?

[GreenF30N26]

https://www.fcpeuro.com/blog/how-to-...t-2-reassembly

[jhall0711]

Thank you.


Appreciate the feedback. Hopefully some others will chime in as well!

[GreenF30N26]

Np. I took a bunch of logs this morning and had PTF review them and they didn't see anything wrong with them so I am likely ok.

Likely best to find a way to ensure the chain and rails move as little as possible during the swap. Either through the oil fill or oil filter hole(likely easier since smaller hole, you can pin the chain) Goodluck

[fe7565]

Replacing the tensioner will not change your timing. Unless your chain was so stretched already that it was overly loose AND you moved the crank shaft at the same time and somehow the chain jumped a gear. Very unlikely.