My cls 55 ran real fast today for about 15 minutes then I feel it got slower about 40 horse slower.it's cold out now . Any amg owners feel the same? Intercooler bosh pump new . I feel. I need upgrade just to keep horse I have.cold weather 1st 10 min the car seems alot faster then later after a few hard runs. It's not in my head. I turn heat on to help cool engine and the heat could burn u it's so hot.

 

Not sure your going to get any responses in the classified section

 

OOOOpps you are right

 

Sounds like a bad pump.. even if new, this is a classic sign. I never feel heat soak.. If it feels slower after 10 minutes, something is wrong.

Pump may be running, but low volume / low pressure