Wastegate Rattle - 2012 BMW X3 Long-Term Road Test
ADVERTISEMENT

2012 BMW X3 Long Term Road Test

2012 BMW X3: Wastegate Rattle

April 26, 2012

x3_eng_rattle.jpg

At least, that's what I think is causing our longterm 2012 BMW X3's cold start rattle. There's a muted buzzy rattling sound in the background that gradually fades away within fifteen seconds or so after a cold start.

To my ears this is textbook wastegate rattle. Cars that have vacuum-actuated or electronic wastegate actuators hold the 'gates open during a cold start in order to rapidly put some fire in the catalyst bricks, thereby reducing emissions. The open valve then dangles freely and makes the jingling noise until it expands and takes up the clearance. Our longterm Kia Optima Turbo did the same thing.

In general this issue is benign and falls into the 'annoyance' category, rather than the harbinger of an actual serious problem, but not always. We'll have it looked into at the next service.

Jason Kavanagh, Engineering Editor


Leave a Comment
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT

Past Long-Term Road Tests

ADVERTISEMENT
Have a question? We're here to help!
Chat*
Chat online with us
Email
Email us at help@edmunds.com
*Available daily 8AM-5PM Pacific
Phone*
Call us at 855-782-4711
SMS*
Text us at ED411