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Mercedes CLS engine noise
There is an intermittent change of engine note on my 2011 Mercedes-Benz CLS 350 CDI. Normally the engine is silent when slowly progressing through the gears but about every two weeks the engine noise will increase dramatically when accelerating or decelerating between 1500-2000rpm. Any idea what's causing this?
Asked on 23 January 2016 by wallywalnut
Answered by
Honest John
Reads to me like the pre-programmed active regeneration of the DPF that takes place around every 250 miles. If the instant fuel economy drops and you smell burning, that's definitely what it is.
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