Hey,

I am new to this forum. I have had my 05 R53 MCS for about 4 years and for awhile I had this problem when it would get hot outside the car would almost go into a safe mode. I have been trying to figure out what it is but it has subsided for awhile and now it is doing it frequently. I have attached a link to a video that is doing the same thing as mine if any of y'all have had the same issue please let me know! It also feels like my power and torque is not as strong as used to be since I replaced the Crank pulley 3 weeks ago.

 

This looks like "limp home mode." I a fault is detected in the car the ECU goes into a safe mode to reduce the chance of permanent damage to the car.

Given the lack of a check engine light I would guess that something is overheating or there's a transmission problem.

Is this car an automatic by chance?

 

When this happens does the AC turn off automatically (stops blowing cold air)?

If so, I would also check to ensure your fans are working properly, but it does point toward a sensor sending information to the ECM telling it it is overheating and it is starting to go into Protected Mode.

Read the codes and see whats going on...

Best of luck.

Motor on!