Hello all. I'm new in the forum and new mini cooper s r53 manual gear box owner ,and already have some questions.
So when i get the car i make complete service. Filters belts pulleys oil spark plugs etc. The car runs fine no check engine light and no other problems.
The biggest problem i have is that the car is missing power after 4000 4500 rpm. Before 4000 4500 rpm it pulls really nice ,but after that is really bad.
Already checked the bypass valve it seems fine me, also make a good look on the vacuum lines they also seem fine.
I don't have a boost gauge so i don't know how much boost is the car making.
So i really need your help how to diagnose what is making the car to lose power after 4000/4500 rpm. Lets hope its not the supercharger.

 

Did you replace the crank pulley? Maybe the clutch is slipping?

 

Hello Mini Chan.
Crank pulley you mean this one

 

Update:
This morning i was for a quick drive 50km and find some open road to press the pedal to the metal :D
In 1 gear around 5500 rpm 6000 rpm the car send a check engine light and EML warning light ,and it lose all power and running like crap on 3 cylinders.
Then i thin the ignition off and remove the key. Restart the engine and EML was gone but check engine light is on at the moment. So maybe that engine light will give me some information about my problem for the missing power?

 

The code may give a clue. Also agree to replace the crank pulley if you haven’t already.

 

Hello all. The code is the famous P1688 .
So what to do now?
Already checked the bypass valve it seems fine ,the spring is not broken and the diaphragm is not damaged ,but i don't know how hard the spring must be? The valve is the original one!
A need info. The bypass valve must be open when the engine is idling or closed???
No vacuum air leaks i really look around but cant find any.
Now the big question the crank pulley ,i think it's not changed. But if the crank pulley is bad the alternator must be not working right ? But i have no problems whit charging system for the moment ,or the AC. So maybe the pulley is fine but i will definitely check it when i have time.
So what is the best thing to do now? The error code p1688 is cleared at the moment. Make a couple of hard pulls but no code for the moment (but still missing power). I'm thinking to zip tie the bypass valve in fully closed and make a run to check is there any difference?

Is there any other sensor that may make the p1688 ?

I'm open to any suggestion

 

Most the time a 1688 code is caused by the crank pulley slipping as the rubber inside fails over time. So I would go for a new ATI crank pulley as the stock ones fail ALL the time. If you drive it hard enough times you will usually smell burning rubber or get it to just fall apart. The ATI is a much better part and will actually dampen better and not fall apart later.
https://www.waymotorworks.com/super-...ulley-r53.html

 

Hello. I will definitely check the crank pulley.
But i'm confused. My bypass valve is fully closed when the engine runs at idle sped.
So i'm guessing massive vacuum leak ? The rubber hose on the bypass valve is brand new....

 

My bypass valve is fully closed when the engine runs at idle sped. It must be open right at idle sped (800-1000 rpm)?
How to troubleshoot that?

 

Today i check the crank pulley (remove the belt and the inner arch) grab the pulley whit hands but i cant make it slip ,so the pulley is fine for the moment.
But the car is still missing power at the top end.

Any suggestions ?