First time poster and BMW noob. Moderately extensive MB and VW background (mostly diesel) but didn’t know what I was getting myself into with this BMW and now need some help and advice. I was a diesel tech (heavy truck) in a previous life many moons ago.

2008 X5 3.0si 150,000 miles. Have owned the car for about 5000 miles and everything was going smooth until a few days ago. Driving home from chipotle, the triple warning light came on (ABS, 4x4, Brake). I attempted to limp it home but very quickly things went down hill. Lost power, idrive flickering on and off, windshield wipers randomly turning on; I knew something bad was happening. Finally got to a safe spot to pull over and there it’s been sitting ever since. I had a friend come pick me up and first tried to add some jumper cables in case something was going on with the battery. No change so bailed for the night as I had work in the morning.

The next day I went back with my scanner hoping that I could clear the codes, diagnose, and get it up and running. I checked the battery voltage before starting which was at 11.8 (seemed normal to me) and with it running (14.4) also seemed good to me. Cleared the codes. The only codes that would not clear (using an autel with BMW program) was the AWD codes (53FC and 53FD.) Seemed fine at idle and in park but as soon as I put it in drive the Christmas tree would come back and everything go nuts. After some online searching, I came to the conclusion that the gear in the transfer case actuator was the culprit. I had work the following day so left it for next time.

I pick up the gear replacement kit from the dealer and go to work on the car. Can’t open the door; Battery is dead. Take battery out and take it to the part store to get it charged. Go back to car and replace gear in actuator. *curse, curse, and more cursing* Boy was that a bitch. Finally get it all back together but can’t do anything else without a battery. Call it for the night.

Go back to auto store after they charged the battery all night and they check it with their battery scanner. Says 400CCA out of 800 and needs to be charged –after being charged all night. We determine a new battery is a good place to start. I buy a new battery (foolishly purchasing a lead-acid). Back to car, get it plugged in, car starts right up. Christmas tree still there. Check voltage and its 18.2! Oh shit, I start to smell something burning so immediately shut off and disconnect battery. I’m talking to a friend who works at a BMW dealership and they recommend changing out the relays in the back. Trip to the dealership, back to the car, new relays, clear codes (awd codes still will not clear) start up and same thing – 18.2 volts and start to smell something burning. Turn off and disconnect battery.

-Feel defeated-

I am now writing this. I just can’t spend much more time or money throwing parts at it not really knowing how to diagnose it properly. The worst part about this is we are $10k into the car and we were planning on selling it next month. We could really use the money from the car sale (I know we ain’t getting our 10k back) but hoping for something!

I am thinking of having it towed to the local BMW indie shop that quoted me $140 diagnostic.

So my questions for you lovely internet land people:
-Any ideas what might be wrong and what I should be looking for?
-What would you do in this situation? – pay to have it diagnosed and try to get it back on the road before selling OR sell it for parts now and tuck my tail between my legs never coming back to BMW?
-What is it worth in current condition VS drivable?
-Anyone in Denver want to buy this thing? Make an offer!

A little back ground information: We bought it at 145k for $6700 last fall (not knowing anything about BMW or their common problems) and I immediately sank $2500 into valve cover gasket, all related sensors, plugs and coils, oil filter seal, thermostat, and all fluid change and flushes. Currently I am just about $10k into it. We were hoping to sell it next month for $6-8k. Everything was working as it should and running smooth until now.

Other random thoughts:

Found this article about K Can failure and suggests:
-E70 BMW X5 damaged wiring behind the CCC/MASK. Incorrect routing of the loom.
-E70 BMW X5 water ingress into trunk.
-E70 BMW X5 wiring damages against seat rails.
-E70 BMW X5 damaged wiring on the 3rd row seats.
-E70 BMW X5 rear view camera not working. Damaged wiring around the rear fuse box.
-E70 BMW X5 corrosion in right rear of the trunk. Splice X15005 / X15006

I checked the wires under the seat and found nothing and checked the wires in the trunk and found nothing but also don’t really know where specifically to look. Our back up camera intermittently works.

Parts guy at the dealer suggested a module (specifically the footwell module) may have gone bad. I couldn’t figure out how to troubleshoot without the proper computer.

Thank you for making it this far and any input you may have. I’ll be cross posting this to the other X5 forums in hopes to reach the largest audience so my apologies if you follow multiple forums.