3 cylinder 1.5 definitely has a failed crank / balancer as belt is not turning battery and overheat warnings. But now it is misfiring on all 3 cylinders and a fault code P1339
Crankshaft Pos. / Engine Speed Sensor Cross Connected is also present. Oil cap has lots of vacuum. can the failed balancer damage the crank position sensor or cause the misfires.....or have a blown head gasket?

 

MINIs control modules (the ECU included, but there are at least a dozen on an F5x series MINI) do not like voltage and amperage undersupply. At all.

Serpentine belt not moving as fast as appropriate (and therefore not spinning alternator pulley as fast as appropriate) due to crank pulley failure --> battery charging issues, battery failure, and other electrical snafu all at the same time.

When the computer systems don't have the electrical they need and expect, the car gets "weird." Really no other way to put it. Replace that pulley (recommend: get an ATI Super Damper instead of a genuine BMW/MINI pulley), ensure that your battery still has decent SoH (State of Health = not the same as State of Charge), charge the battery back up (or replace it if its health is poor due to whatever the charging snafu did to it), clear your codes, and try again.

Also: get a scanner that can read (and clear) BMW/MINI-proprietary codes, not just generic OBD-II codes (P-codes are OBD-II codes). Lowest-cost entry point I know of is the combination of the BimmerLink app and a compatible OBD-II adapter. Sub-$100 for the combo. Maybe way sub-$100.

Hope this helps.

 

Yes this helps...I'm just concerned about the misfires in all three cylinders. I'm concerned about putting a pulley on a car that might need an engine.

 

I hear you. But think of it another way. How well do you think your engine is going to run -- with computer-controlled timing -- when the computer doing the control doesn't get enough voltage/amperage and gets weird?

See the problem?

Again, MINIs do ***not*** like undervoltage and/or underamperage. MINIs with dying batteries or other general electrical fail causing things like misfires are almost legendary. You hear about this more with R series MINIs, but that's because they are older and tend to be in worse shape (because older = more time to be poorly maintained under owner history that wasn't up on proper maintenance). F series MINIs are going to be subject to the same, though. Low voltage causes bad sensor readings, bad sensor readings mislead the DME (the ECU, in more general terms), starve out the BDC, blah blah blah... and really really not great if the DME itself is getting weird because *it* is being starved of power.

Net is that you don't really have a way to know until you take the electrical fail out of play. That said, the B series engines in the F series MINIs tend to be very reliable. Misfires because Bad Engine are not impossible, but they aren't even remotely common. All-cylinder misfires out of nowhere for no good reason (while clear electrical starvation is going on, cough cough) are even less common.

Just to make your life more complicated, whether the battery is charging or not is not old-school where so long as the alternator is getting spun, charging is happening. It's under computer control on all the F series MINIs -- that computer being the DME. Double your trouble and double the "fun" when electrical supply is a mess.

 

I believe what you are saying Can I test this theory with a battery charger attached? Again I don't want t to be throwing money at a bad engine I mean it's running absolutely terrible now....the weird you mentioned. It's very ugly

 

Maybe.

Here's the approach I'd take:

(1) Turn the car on (but do not start the engine) and clear all codes.
(2) After clearing codes, scan for codes once more to ensure that nothing else is hanging around. Then turn the car off and leave it off.
(3) Charge the battery as far as you can charge it. Don't rush it, give it as long as you can / as long as the charger wants to (and if you aren't using a charger that is smart about AGM batteries, get one -- you're eventually going to need one anyway, whether for this car or not).
(4) After charging, get your code reader ready.
(5) Start the car and see if there is any improvement. Don't run it long, just let it settle in, maybe let it run for a few minutes tops. You already know your balancer is toast so don't expect or try to get the car to act like it's supposed to behave normally with a shot balancer/crank pulley. And the car will be draining the battery for sure while it's running. Your goal is to see if starting the car with a fully-charged battery made the car behave better in *any* discernible way, even if transient.
(6) Turn the engine off and scan for codes.

There's one problem with this plan. If your battery isn't properly holding a charge any longer, the initial start is going to drain it really badly and the whole exercise won't tell you anything meaningful -- you'll get the same symptoms you already have.

If the test flunks out hard, the next thing to do is have the battery load tested and its SoH determined. Not voltage tested, LOAD tested -- and not "how many volts are at the battery posts," you need to get an SoH number.

Unfortunately for you there is no way, when running a modern vehicle with known-funky electrical, to differentiate engine control problems from electrical problems. And there are very few ways to resolve electrical problems without paying for it (new battery, new balancer, or some pretty magical repair).

That said, "bad engine" is your last conclusion, not your first, unless the car has been taken care of so poorly that there is real other evidence of things other than the known causes you have in front of you (known causes that would make *any* engine of this kind run messily).