Diesel, Engine Noise

[rsggo]

Hi my problem if anyone can help, when I start my diesel anytime during the day/night for the first 30 mins on idle the engine sound so rough, when I rev to about 1500 its ok, below this it sounds like a tractor.

Is this normal for a diesel or is there something I can do/change to reduce this noise.

Can anyone help?? or advise me??

C220 cdi, 2002, 49450.

 

[jberks]

You could try a different oil, though not sure which, something a bit thinner perhaps. I find my diesel a little bit tractor like until she warms up a bit too. But its 2-3 mins, not 30 and my reference point is a V6 so the bar is a bit high.

 

[Wezzel]

Sounds like diesel knock. I used to get this until I started adding infector cleaner to every fill up.

The cleaner also has a cetane booster and the increase in the cetane number of the fuel can decrease the amount of knock by shortening the ignition delay.

Less fuel has been injected by the time combustion begins and it has had less time to mix with air. As a result, the rapid pressure rise, along with the resulting sound wave, is smaller.

Mine has been fine for over a year.

 

[rsggo]

Many thanks.