my 05 MCS manual has developed an intermittent no start or no PS problem

first few times many of the dash lights would come no while driving and power steering would not be working, could pull over and turn key offf and on and car would restart with power steering and lights working as normal.

also few times when starting would just crank and not start, few cycles with the key on and off would result in it starting and working fine again

today it did the no start again and i noticed the dash lights didn't come on when the key was on, and when cranking. actually stranded me
came cack a few hours late and it cranked and started as normal

have been searching posts here for past week or so and have a few hunches as to the possible problem.

1) alternator issue not triggering the PS PUMP and causing electrical system to malfunction

2) ignition switch causing intermittent running issue

3) intermittent computer communication issue

4) replaced relay related to engine computer

have eliminated few possible issues i think: cleaned grounds, harmonic balancer slipping, battery good, no cack engine codes

wanted to see if anyone here could point me in what direction to go next

thanks!!

 

How old is your battery? Check battery install/purchase date and voltage. (KISS) Keep it simple s...

 

Thanks for the reply, ill check the dates but

mini scanner showed good battery voltage

never had any battery issues, always cranks fast

 

Sounds like a bad battery or bad ground. When you say voltage is good, meaning the alternator is charging?

 

thanks for the repy

alternator charging and battery full voltage plus always cranks well

 

I would have the battery load tested, just because it puts out 12+ volts doesn't mean its in good shape. Alternator should be charging 14+ volts no load. If that all works out, I would look into the ground straps, make sure they are in place, not rusted and have good connections. There are 2 straps I believe, one on the front passenger side of the engine compartment , can;t recall right now where the other one is, you can search in this forum for the location of the other. Hopefully it's as simple as that.

 

+1

Intermittent electrical issue? Sounds like ground

 

+1 on taking battery in for a full test. Also, +1 on checking all major ground connections, here listed in Uncle Bentley page ECL-18 through 21. NOTE: figure 13 shows locaiton of EHPS ground X173, for power steering pump 'underneath engine compartment fuse and relay panel 3':


Bentley Mini Cooper Service Manual page ECL-18 Ground Locations

Bentley Mini Cooper Service Manual page ECL-19 Ground Locations in Engine Bay

Bentley Mini Cooper Service Manual page ECL-20, note Figure 13 shows location of power steering pump ground

 

thanks everybody for such helpful information
i will address the issues brought up and reply

 

problem seems to be fixed, after cleaning all grounds, load testing battery and changing relays with no improvement went ahead and changed the ignition switch. been about 4 days now of running around in the car and had no starting issues

took about 20 min to change, easy job

thanks