[davinreader]

Hi everyone,

In the last several months my E91 LCI has had an intermittent rattle coming from the exhaust/rear at idle. It comes on randomly (maybe more when it's cold) but only when stationary, I can hear it audible go away as I leave the light.

I've taken a look at methods such as disconnecting the actuator in the trunk or the "golf tee method" - except that in the E91 there is no actuator accessible in the trunk and no vacuum line by the exhaust under the car!

Even the $129 exhaust rattle kit I've seen online doesn't work since there is no visible butterfly valve.

Am I missing something or am I in need of a whole new exhaust system if it starts to bother me too much? TIA

[bimmermech123]

Remove the exhaust tips and clean them out, rocks and debris tend to accumulate between them and the actual muffler tips.

[eljay]

I would lift the car and check all the shields around the exhaust. They tend to corrode around their attachment points and then the shield drops slightly and would vibrate when the car is moving or exhaust is vibrating at certain engine speeds.

[Serf27]

Start the car and while in park/idle, put downward pressure on the exhaust tips to see if the rattling goes away.

Or slide under then and shake the exhaust around.
A lot of the times it is the covers on the muffler tip that rattle, as mentioned above.

[StradaRedlands]

Check your hanger as well... could be degraded and split/non-existent.
Probably not it, but can't hurt to check.
https://www.fcpeuro.com/products/bmw...bi-18207590154

[davinreader]

Originally Posted by bimmermech123

Remove the exhaust tips and clean them out, rocks and debris tend to accumulate between them and the actual muffler tips.

Update: this seems to have solved the issue! I cleaned the exhaust tips two nights ago and I haven't heard any rattle come back yet. Thank you for the suggestion!