How does one tighten the belt tensioner pulley bolt to 28 ft/lbs?

[Epsilon]

In my pursuit to find that cold start squeaking noise, I replaced the belt tensioner pulley again in 3K miles. As I used a torque wrench from the top of the car to tighten the bolt to 28 lb/ft, the pulley arm just wants to swing down and I can never reach the torque spec. Any advice would be appreciated.

On a side note, I have replaced all the pulleys driven by that belt, the belt itself, alternator, and the AC pulley and belt. After this pulley change, I found the cold start cricket noise to be even louder and coming what sounds mostly like between the radiator and engine. weird huh?

Here's my old thread with the problem:

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/111344-replaced-alternator-and-pulleys-twice-and-still-hearing-crickets-on-cold-starts

[Slideways]

You should be able to reach the max range of the tensioner in the tighten position and the torque wrench will eventually click at the end of its range. That is for the hydraulic tensioner for the main belt, btw, not the mechanical one for the A/C belt.

[Epsilon]

Thanks! I was afraid I might overextend the tensioner spring.

[eacmen]

Thanks! I was afraid I might overextend the tensioner spring.

The main belt tensioner is hydraulic not spring.

The bigger risk is stripping that allen head bolt if you still have the original tensioner design.

[sapote]

1. Thanks! I was afraid I might overextend the tensioner spring.
2. On a side note, I have replaced all the pulleys driven by that belt, the belt itself, alternator, and the AC pulley and belt. After this pulley change, I found the cold start cricket noise to be even louder

1. Wait, do you have the mechanical tensioner or the hydraulic unit? I believe all M3 came with hydraulic. On the mechanical tension, there are the "locking' holes on the left side and inserting a small screwdriver into the holes will lock it from swinging down.
2. To kill the cricket, I used a steel straight edge and check the alighnment from the crank pulley to WP and to tensioner -- all should be on the same plane. If not the belt will try to climb up the pulley edge and then fall down causing the cricket to chirp.