I have a 2011 cooper S which I bought used with 79k miles, Im up to 82k now. Im just curious on how to tell if my valves need a cleaning or not since I have no knowledge of what my car performed when new.

 

Engine running rough, idling poorly? The only way to know for sure is to remove the intake manifold and inspect them with a scope. In any event, the n18 engine isn't prone to this problem like the n14..

 

Scope the intake you are a 2011 which does not have the build up as much ( does happen though ) as the pre 2011 MINIs w/ the N14 engine.

https://www.northamericanmotoring.co...-cleaning.html

 

Really the only way to know for sure is to pop off the intake manifold and have a look.

 

I am hoping that by using my 2011 MCS HARD that carbon buildup will be kept at bay, or at least minimized. These engines love to rev, and were not built to be lugging around at low RPM's. I am also using Seafoam in my tank every 5 fillups or so. I know, that shouldn't help, but it will keep the injectors clean, at least. At 56k, I have no issues that I would consider to be carbon-buildup related. I am just dying to crack the intake off and have a look, though.....maybe in the next few weeks.

 

Seafoam will not clean injectors. And it doesn't really clean the intake ports. There's a bunch of videos that show you how to mechanically clean intake ports/valves. I recommend you remove intake mani and inspect with a flashlight and mirror. Meccanically clean with brush and a solvent. Such as diesel fuel, thinner or the BG intake cleaning kit. Please perform at own risk and ensure valves are closed when doing this. This would be a good time to replace valve cover gasket and intake gaskets. I did did and the car really woke up. I also installed the BSH oil catch can and plugged the passenger side PCV hose on the valve cover to reduce buildup due to oil mist from PCV system going into intake ports. Good luck.

 

^This^, or go to your friendly neighborhood MINI shop and get it walnut shell blasted.