My 05 Cooper S is getting close to 75k miles and it's starting to feel a little sluggish. Maybe I'm just imagining things but I drove an 06 CRV today and that thing didn't feel way far off zippiness wise atleast at lower speeds compared to my car when you floored it-- considering I have a 15% reduction pulley I don't think that's supposed to happen :D

At 75k miles is my bypass valve pretty worn by now? When did you guys change yours out? I'm assuming that's what's causing any lack of power since the car is throwing no CEL or having any issues. I'm considering upgrading to a Detroit tuned bypass valve anyways.

 

I keep mine zip tied shut and had the code tuned out...its makes boost SOOOO much better . Try ziptying the bpv shut and see if your performance improves. And IT ONLY THREW a code once I added more mods so maybe you could get away with it tied shut and no cel..ONLY downside is the iat run like 10degrees warmer because its making more boost more often, big deal
clean your map sensors also. That always helps if its never been done.

 

Sluggishness can have multiple causes, but a faulty/old BPV might be one of them indeed.

I changed mine with 100k and modified it by adding 2 washers to add pretension to the spring.



Other culprits
-plugs
-coilpack
-ht leads
-o2 sensors
-injectors
-fuel pump
-vacuum line to Fuel Pressure Regulator

 

Fuel filter too.

 

Good one, forgot about that! I replaced mine as well at 100k

 

Thanks for the suggestions guys!

 

Just for reference.......

I installed a Detroit BPV back in 2011 when I bought my MINI, at 88K miles on it. It's now got 188K miles on it 9 year later.....and I'm running the same BPV, with no issues at all.

 

Was your original bypass valve badly worn when you replaced it? Did it make a big difference?

 

Yes, the spring was broke and it wasn't closing all the way. Yes, it made a big difference putting one in there that worked properly.