2005 156k mile R53 has a sputter


I've been rallying my new to me mini around and made a discovery the other day.


Starting it up in the morning the exhaust makes a "Puff" at idle out the tail pipes. Runs fine and idles fine so I didn't give it much attention as it goes away once its warmed up.


Coming down a hill the other day I grabbed a gear and rode some engine braking down the hill and the little puff became a very noticeable pop, pop, pop every time I'd give it some gas then backed off.


I'm planning on some upgrades and was just curious what you think I might be? I've confirmed that Pole #3 on my coil looks like a rusty nail so I'm sure that's not helping. Anything else that might cause that?


Also I read the thread lately about the guy with 380k+ mile mini rebuild and how his cat was plugged up. At 156k miles I'm starting to wonder if a new cat is something I should do too?


Anyway, look forward to the feedback.
Thanks!


Eric

 

The "pop" when you get off the gas, as it returns to idle is normal...it was added to the ecu to make the car more fun...many change the exaust to make it louder...
The little mini backfire sound...was very mild in pre2005 cars, but was made louder in 2005+...

 

Valve guides? The "puff" at startup when cold may be due to small amounts of oil leaking by the guides after it was driven last. It then goes away as the small amount of oil burns off, the car warms up and the seals warm up. DEFENATELY take care of the coil post issue. You likely already know this, but inspect (replace if necessary) the plug wire(s) as well for corrosion and re-install with dielectric grease. I had a bad one (#2 oddly enough, as #3 is FAR more common as I understand it.) that caused a pretty bad misfire. Also, check out your plugs. IF you are burning any oil due to valve guides, depending on the extent of the issue, they may get a bit cruddy too. Good luck and when you do find the issue, please post it here so we can all benefit from your experience.

 

As was stated, the puff of smoke is probably due to valve guide seals.

The burbles are a part of the tune.

Don't replace a catalyst unless you have fault with the current unit. We don't see many cats fail, usually we're replacing headers due to non repairable cracks.

If the coil is too far gone and won't clean up nicely replace it with an OEM unit, don't buy into the "performance coil" gambit.

 

Thanks for the info guys.


To be clear it's not a puff of smoke and it hasn't been burning any oil its just a little puff of exhaust gas out the tail pipes at idle. Like a purrrrrrrrrr, poof, purrrrrr, poof, purr poof, prrrrrrrrrrrr. then goes away once its warm.


I ride dirt bikes and used to race sport bikes and love the deceleration pop. That's excellent to know that its built in. Cant wait to make it louder soon!


So for spark plugs. I was going to do the MSD coil and wires but I'm not sure if I should do the colder plugs without having any other mods yet. I didn't want to buy a new set of stock plugs then swap them out for colder ones in a couple months... Would running colder plugs on a car with only the MSD coils/wires and CAI be okay?


Eric

 

IMO you're going to waste money on the MSD coil and wires, the stock coil supports 400+ HP, the only benefit of the MSD coil is the points aren't steel and therefore don't rust.

If you do end up spending the money on MSD components USE THE STOCK COIL PACK BOLTS AND ISOLATORS, if you don't you'll end up breaking your valve cover.

Running colder plugs won't hurt the car, you'll be fine. We recommend NGK plugs, the Brisk plugs have fallen apart on multiple cars I've personally worked on, and the cheap auto store plugs are known for coming loose and ripping threads out of the head.

 

mostly just plugs are ONLY needed if you get a pulley on the sc...
Tol coil a plug CAN cause issues...mostly just fowling...but likly OK
pack...you pick...
I used a MSD cause it was cheaper than OEM and had brass terminals, no issues for 7 years...know a few tuners who say OEM is best...but imo, just get a OEM level/$$ replacement....no need to pay extra...you don't need it..it won't gain you diddly squat at even the max boost levels before the motor blows on highly modified cars....

 

+1 NGK...they work well on a MINI...
Either the multi electrode OEM style, or the iridium.

 

Sounds like I'll just buy the colder NGK iridium's then. As money allows I'm going to do some performance upgrades. My plan is to do the CAI and coil/wires/plugs the same time I do my first oil change on it.


Next step will be a big expensive one and I'll pull the whole SC and service it before I put pulleys on. But I'll likely do a header and bigger injectors among other things and then haul it to a shop for a tune.


Eric