Last weekend I installed the Way Motor Works pulley kit (15% pulley, belt and plugs). Everything went in just fine, but now I am getting some troubling "popping" sounds when the car is coming down to idle from higher RPMs (when decelerating or coming to a stop). I reset the ECU after the change. The popping sounds is noticeable, and sounds a bit like backfiring. It doesn't do it every time the car drops to idle, but it does it enough to raise some concern. Any ideas what might be causing this or what I can do to make it stop?

 

...You sure that isn't just pop and burble? Plenty of R56 owners would love to have that sound

 

It could be, it's just a sound that wasn't there before. What's the distinction?

 

Well, being an R56 owner I'm not sure how qualified I am to answer the question as to why the sound suddenly showed up after installing the pulley.

I can tell you that the pop and burble is supposed to be there for R53s, but it is especially prevalent for MINIs built between 2005 and 2006. People complained so much about it, a service bulletin was put out. This resulted in MINI taking the sound away for Cooper S MINIs built between 2007 and 2010, only to put it back for 2011+.

My best guess would be the 15% pulley just made the sound much more noticable in your 2005, but maybe some R53 people can chime in and give you a better answer.

 

Yeah, the all the R53's normally do this. Check some youtube videos to make sure that the sound matches your description, but I think it is a sound you will fall in love with. Not sure why the pulley would make a different either.

 

That is the signature burble of the R53, it is normal. Enjoy it!

 

D'oh!

 

with my catless header and borla exhaust it's pop lot louder too and love it.

this might help - http://www.motoringfile.com/2005/06/28/exhaust_popping/

 

Thanks for the info everyone. I haven't had the car that long and I guess I just hadn't noticed the sound. Good know know that all is well with the car.

 

 

My 10/2006 build snaps, pops and burbles.

 

Like everyone else said, it's completely normal. Maybe the pulley is making it more noticeable because you're building more boost, thus creating more back pressure? That would be my only guess. Enjoy it.

 

My car is too early to do it all the time, but occasionally it does.

 

The software on 2005+ cars had the burble added or made better to improve the experance...i love mine...more noticable after the pulley...many folks initally complained, but it became a much loved feature.

 

Close... More boost = more heat thus the cat gets hotter. MINI's are programmed to have the burble by pushing excess fuel into the exhaust.

 

So is the pop and burble possible with an automatic transmission on an '06 MCS? I hope so as I plan on doing the pulley conversion... Right now, the MR2 Spyder I drive has a hi-flow cat and a stainless steel dual muffler and has a heavenly sound of pop and burble when decelerating! To the original poster, if this is the accepted "safe" sound, enjoy it, good stuff!