Rattling Noise Only at low rpm when transmission is in gear

[Bladecutter]

Originally Posted by dennis

OK. It seems unanimous- engine mount, leading to exhaust noise. Just a few questions: will this cause damage to drivetrain and how difficult is it to replace the mount? Should I replace all? Assuming I should.

I don't think its unanimous.

You should check one more thing, however, before you start spending money.

The muffler has a bracket that mounts to the rear of the transmission.
On my car, the three bolts that support the bracket and muffler are all broken.
When the engine is at the right rpms, these bolts start to rattle, and make one heck of a racket. This rpm point is usually a fast idle speed, so right around 1k rpms.

Take a look.

BC.

[dennis]

do you hear the rattle in gear only? Mine is only in gear, which makes me think its due to the engine torquing

[Matt Fredrikson]

Mines also rattles in gear on the gas only, 2800 rpm in gears 12&3 everytime o the number?? Gonna beat on the heat shield this weekend.

[dennis]

Yep same problem. I ordered a new mount- the 987 mount. I am going to replace it. It has 34k miles and its a 2001 so im thinking due to low use mount rubber dry rotted??

[tuanle16]

holy crap. i thought i was reading my own post. 02 non s boxster having same exact issue. about to buy a muffler, but now that i see your post, wondering if i need to buy mount instead. how did you do?

[Autobot152]

Did you guys figure out the rattle? Exhaust leak, heat shield, motor mount?
Just got my 2000 boxster and have same annoying rattle at low Rpms in gear. Thx!

[madmods]

As far as my knowledge goes, boxster’s cats are well known for failing. The result is quite funny... the cell unit in the cat frees itself and bounce & roll in the housing and eventually break apart. That create the same rattling sound as described in this thread.