MKB Engine Noises: Rumble & Knock at 2900 RPM (Solution)

Author: Michael II.

Cause:
In some cases, the exhaust system may resonate due to its natural vibration characteristics at speeds between 2,800 and 3,000 RPM.

Solution:
Make sure the noises are not caused by other factors (for example, the heat shield mounting, the exhaust system, the resonator...).

If the noises occur within a very narrow tolerance range of +/- 50/min and between 2,800/min and 3,000/min, a silencer with the part number 1J0 253 651 must be installed on the exhaust pipe.

The silencer is screwed directly behind the crimp sleeve, between the catalyst and the pre-silencer. The vibration damper (red rubber element) should be oriented upwards in the area of the tunnel.

It is important to ensure that the exhaust system is properly adjusted on the tunnel bridge.

When adjusting the exhaust system, it is essential to ensure that the mounting bracket on the rear silencer is in the correct position. In the cold state, it is slightly tilted in the direction of travel, so that when the system heats up and expands, a neutral position is achieved at the mounting point.
Please provide the German text you would like me to translate.
Bye.

Michael.