Chain tensioner swap jitters
 

I have done this on every BMW I have owned.
It still makes me cringe when I start the engine.
Sounds like a dying alien in a garbage disposal.
It doesn’t last overly long. Is there any way to speed
the hydraulic action up?

Replace the tensioner with OE tensioner. How long since tensioner replaced? They wear out

X5 just turned 70K. Low miles, but nearly 2 decades .

Which motor? Are you sure it's chain rattle not vanos rattle?

I have the 4.6.is engine.


I don’t know what the rattle I’d from. On a cold stone engine, it’s
about 1 second of rattle. If engine is warmed up to operating temp,
then I get virtual no rattle. It idles incredible smooth. very quiet.
No stumbling, or hesitation what so ever.

Rate a recording. The M62 has only one chain so takes a lot of force to keep tight. I've witnessed a few cases of exactly the symptom you describe where it was the tensioner and replacing made the problem go away.

Tensioner is $60-100

Timing chain guides are $800-1200 in parts and 20-30 hours to install.

Were it my car I'd order an OE tensioner and crush washer today. The vanos rattle I don't think it's common with the M62. The vanos seal does fail and I've reworked the seal on those when doing chain guides.

New INA brand tensioner installed.
About 2 seconds of clatter, then smooth as butter.

I overthought this.
So easy if you lock the tensioner in the collapsed state.
You Tube University helped me.
And my Brother X Men.

I'm not sure what you are saying.

Did you install a new tensioner and it's solved the starting rattle?

If you get rattle should be only first cold start of the day.

If it happens more than once it's likely the check valves are leaking.

New tensioner installed. Runs great.
Old spring about 1/4 inch shorter.
INA brand for the tensioner.