I purchased 2005 MCSC last week and picked it up this weekend. Since the drive home from the purchase point was 1000 miles I had a lot of quality time behind the wheel. One thing I notice was (most noticeable between 3 and 4 thousand RPM) the engine either has a surge or slight loss of power when holding the throttle steady. Any thoughts?

 

A good place to start would be a search for the infamous YOYO and a BP valve with a tired spring. This condition can be cured by getting a BP valve from Detroit Tuned. A second option would be to take it in to the dealer, you still have warranty, and have them access the condition.

 

Thanks for the reply, I am going to stop and the dealer today and make an appointment for a check up. I wanted to make sure this isn't normal behavior.