Defect Poll, Unibody MBP: Fans Make 'Grinding' Noise at Min RPM w/ Base @ 45º Angle

[dcMobile]

Hey Late 2008 MBP Owners...

I tend to use my MBP in bed a lot, propped up on my thighs at about a 45º angle, and I've noticed a grinding noise from the fans when using it this way.

I've just learned that this grinding noise is not a result of case compression, as even if I lift the machine up by the sides and rotate it fore and aft in space, there's a 10º zone (between 40º and 50º approximately) that the fans make a distinct grinding sound.

Note that, for me anyway, this will only happen between minimum fan speed (1990 rpm) and ~2300.

Let me know what you guys find. Be sure to put one ear a few inches away from the hinge area when you test!

 

[MICHAELSD]

It's definitely there for me. I don't really consider it a problem, though, since I never use my MacBook Pro that way.

 

[J the Ninja]

Nope. Just tried rotating mine from flat on my desk to 90 degrees. Aside from almost getting hit in the face by the NEW Easy-To-Operate-Hinge and the NEW Screen-Covered-In-Really-Heavy-Glass conspiring to make the NEW Flops-Over-From-Its-Own-Weight-Like-A-Baby's-Head lid, everything was fine. No noise.

 

[xpovos]

My fans were doing the same. The left fan was especially offensive. Sometimes tilting wasn't even necessary as it would grind/rattle even when flat on a table, but the noise got much louder as the laptop tilted.

I had both cooling fans replaced under warranty and have had no such fan noise ever since.

(Of course, I now have the low-brightness 9400M flicker that probably requires a logic board replacement.)

 

[darrenscerri]

Nope I don't have this problem.

 

[raviliousness]

No no change in noise at 40-50 degrees.

Although the left fan has had a continuous (fairly quiet but noticeable) high-rate ticking sound at 2000rpm ever since playing some games with the fan up high at around 5000rpm.