Alright Mini Land, I'm in need of some assistance. I have an '06 S that I haven't had any problems with save for replacing the hydraulic tensioner a couple times and a slight "yo yo" around 3k RPMs that I have been meaning to take care of by replacing the bypass valve. The car was still very drivable, everything worked, it started every time, never threw a code or anything weird.

So, a few days ago I was driving and smoke started pouring out from under my hood, the dash lights light up and the vehicle dies. I pull over, push start it and find that with the A/C on the belt stops spinning, my dash panics and the belt slips. I keep the A/C off and drive home. I find that the A/C still produces cold air for the brief moment it is on before I'm assuming the compressor freezes up and thus stops all other pulleys. Never had an A/C problem before. The vehicle still seemed to build boost just fine and hit around 12 lbs.

I also notice that now my battery dies after maybe a few hours of sitting. My volt gauge shows over 14 volts while running and I drove it for almost an hour the other day and the battery was dead later that evening. So I probably need a new battery but I never had a problem until this whole A/C issue popped up.

I had a DT BPV and a new, shorter belt to go along with my 17% pulley that I installed today thinking that maybe the old, loose belt wasn't helping matters any and I might as well put the new BPV on while I'm in there. I jumped the car and all seems well but now it won't build any boost and I'm throwing codes P1237 and P0500 and the vehicle goes into some sort of limp mode where I can barely reach 10mph. I can turn the car off, restart it and drive a while longer before it throws the code again. Did this about 5 times trying to get back home. There are no vacuum leaks I could find but obviously it sounds like I'm leaking boost somewhere as now I will maybe hit 2 lbs.

So, when it rains, it pours. I have several problems that need to be addressed:

-A/C on causes problems. Still blows cold. Freezes shorter and stock belts. fans kick on like normal.
-Mystery battery drain. Could just be coincidentally I need a new battery. I can take it to be tested but it seems odd to me that with the alternator supposedly producing 14+ volts at idle that it would die so quick when sitting when it never had a single problem until the A/C issue. I even took out my glove box light just in case.
-Loosing boost. Didn't have this problem until the DT BPV install. I must have messed something up. I have the VGS mod as well and have had it for over a year. Those lines are good without leaks. I went from about 12 lbs to about 2 lbs as shown on my boost gauge.
-P1237 code, which I thought would be fixed by the new BPV.
-P0500 code. Perhaps I bumped something in the passenger wheel when I had the liner out?

Any Ideas would be helpful.

 

P0500 Vehicle Speed Sensor "A" - The battery and this code may be related. See this thread here. How old is the battery and when is the last time you replaced it? The battery is perhaps the most important electrical component on the car, and due to its design and nature, is perhaps one of the most troublesome. Here is a DIY on its replacement if needed.

P1237 Secondary Upstream Manifold Air Pressure Sensor Low. Here is a thread on NAM about it. Make sure there is still no vacuum leaks in the BPV. Do a smoke test on the vehicle and make sure there aren't any other vacuum leaks present. Here is another thread for it.

-Luccia

 

I have similar issues with the AC on and the belt not moving. I have narrowed it down to what I believe is either the tensioner or the compressor. Are you getting any noise by the belts? I have a metallic noise somewhere.

 

Sounds like a Crank Pulley rubber failure... when the tension goes onto the belt the pulley spins on the now old rubber (it can cause some smoke and smell of burning rubber).

You can look behind the right front wheel where the belt and pulley are and see if you have what looks a large amount of black powder building up in that area, and on the face of the crank pulley.

...with the Crank Pulley failing, you won't get the boost you should (the SC isn't spinning up) have the sensors read that things are off, the Alternator can not spin fast enough to charge the battery, and you can possibly overheat the car because the water pump isn't spinning fast enough to circulate the coolant.

Best of luck.

Motor on!

 

Check crank pulley as JABowders stated. Pull your fender cover and look for black rubber throw-off. you should see some around the damper area or smell burnt rubber. Buy an ATI damper, they are about 340$ and a new crank bolt 7$ and a little blue locktite.

 

I've been pretty distracted lately since I bought an '07 R56 with its own list of problems and the R53 has been sitting.

Here's what I've done:
-Replaced the battery. I've had the sensor issue once since then but I also haven't really driven the car.
-Drained and filled the supercharger with fresh oil
-New water pump, orings, coolant and such
-Replaced the DT BPV with the stock valve. No change.
-Removed VGS mod. No change
-Removed OCC. No Change.
-I had broke the tab on the supercharger inlet tube so I made another hole, bought a new gasket and even sealed the area with high temp silicone just to be sure there were no leaks. No change.
-reseated the 3 hard plastic vacuum lines (2 in supercharger inlet tube and 1 in supercharger itself). No change.


I tried to do a smoke test with a fog machine but gave up quick as getting it all setup sucked. I did recently order new intercooler boots even though I have examined mine throughly and have concluded that while stretching them in the dark with a flashlight to check for leaks they have none. I could be mistaken so it's worth a shot.

Besides this I've also used carb cleaner all around the vacuum connections to check for leaks and have found nothing.

Currently the car will build boost to a few pounds and then it tapers off quick, just as it was doing before.

I plan to throw the boots on and see what happens. If that doesn't resolve it I'll revisit the smoke test and go from there.

*I'll look into my crank pulley. If the two parts had separated though, wouldn't the pulley not spin at all? My cooper drives fine so long as I don't try to push it. I can take it on the freeway even.

 

The crank pulley is designed in several pieces and the rubber isolates and dampens vibration. The pulley is most likely slipping. Do you smell any rubber smell and you will get a ticking to what sounds almost like a thrown rod. The noise will depending on how bad the pulley is. The car will go into limp mode when it slips bad. Water pump/blower will be running at a lower rpm. The smoke might have been from the coolant coming out of the expansion tank and burning from the exhaust manifold since it is turning at a slower rpm since the crank pulley is slipping.

Usually, if the AC compressor freezes, the belt will squeal and the other pulleys will be running fine. Look around the timing cover. You might see rubber throw off.

 

If you can get to your crank pulley try scribe a mar from the center all the way out to the edge. Drive it and take a look to see if the marks line up. If they don't there's your issue. If they do it might be your a/c compressor.

 

After doing some research and these responses I'm starting to believe it may be the crank pulley. I went outside to check for dust and there was some but not much. I figure it could easily have come from the belt that was almost 6 months old. I had cleaned the area up when I replaced the supercharger oil so there isn't much evidence left and honestly I can't remember if there was a significant amount of rubber junk. Looking at the pulley it looks fine but this idea of drawing a line is brillant, I'll give that a shot.

I know pulley discussions have been beat to death but my quick question is whether anyone knows if the vibrations from a nondampened pulley are terrible compared to stock? This Cooper will be sold as soon as I address this issue so I want to keep my expense low but not push away potential buyers with cabin vibrations.

 

It's the crank pulley...yank off the passenger side tire...
Remove the liner...and look...
About a 15 minute job to inspect it...
IMO should have been the first thing to check once you noticed the belt stopped underload...
IMO get the ati or prw damper.... The "lightweight" ones are junk and can DAMMAGE a motor long-term.

 

The belt only stops when the A/C is turned on. Is it not reasonable to assume that the A/C is having an issue? After reading up on this issue I understand why turning on the A/C and it stopping the belts is a symptom of a bad pulley but my assumption was fairly reasonable, which is why I pursued the vacuum leak.

I'll let the new owner know that there are better pulleys out there for long term motor health. My job is to get this ready for sale and I'm not doing a disservice to the new owner by replacing the [potentially] damaged pulley with a new one that will work fine in the short term.

 

ATI is another good damper to buy. Numerous threads on this and I have one in my sons car. Smooth and it is a daily driven car. The scribe mark is an excellent Idea. The crank pulley we had fell apart. The metal sheared off near the center bolt. I repeat, do not buy a cheap damper/balancer/pulley. Be prepared to pay about 350-400$

 

I marked the pulley and after letting it run with the A/C on the belts stopping spinning, I turned the car off and located my marks, which were no longer lined up. I'm ordering a new crank pulley now. Thanks for the suggestions fellas. Now I just need to wait for it to come in, install it and hope it does the trick.

 

Now I'm a bit stuck on what to do. While trying to remove the stock crank pulley with my pulley puller, one of the 3 M6 bolts that is screwed into the pulley to extract it broke flush with the face of the pulley. Any ideas? I may try getting in there and slotting it so I can remove it since damaging the stock pulley doesn't matter anyway.

This broken extraction bolt is a good example of how hard this pulley has been to remove. The crank bolt zipped right out with my air gun but the crank just won't budge. it has flattened completely the tip of my puller and is not treating the threads well on the center bolt tightened to remove the pulley. I tried heating the pulley as well as lubing everything up well. Any ideas?

 

Big hammer?

 

I ended up getting the broken bolt out and bought a new one to replace it. After a little wrestling I got the pulley off. I found that the rear belt part had been grinding into the block but only cosmetic. The new pulley slid on after being heated and after wrestling with the pulley again to tighten it to 85 ft/lbs by myself I finally got the car back together and took it for a drive. It built boost just fine on the host drive. I didn't want to push it but after the storm that just kicked in I'll go over finishing touches and then take it out again. So far so good. Thanks for your help everyone.