Looking for some help

I have a 2009 S40 R Design with Aisin 55 Front Wheel trans.

Im facing a "rattle" alike noise when switching from Automatic driving to Manual using the gear box. As you aware, when switching from automatic to manual, the motor RPM increases while driving uphill, and that switch to manual makes the motor to rattle, the noise is very noticeable like if the engine was not tuned.

This above scenario is the only one way where the engine showcases that issue, cuz while driving automatic there is no noise at all.

The S40 has +180 k kilometers and its regularly well maintained.

Any ideas on why this issue is happening?

Thanks in advance, Gabe

 

is your rattling mechanical or really pinging (aka pinking)? I'd think that pinging would throw a misfire CEL, a mechanical rattle could be related to RPM or engine torque (thinking motor mounts etc) or some resonance or exhaust issue (heat shields?)

 

a mechanical rattle could be related to RPM or engine torque (thinking motor mounts etc) or some resonance or exhaust issue (heat shields?)

 

a mechanical rattle could be related to RPM or engine torque (thinking motor mounts etc) or some resonance or exhaust issue (heat shields?)