E60 No Crank Diagnosis

[93 525 Paul]

So the 07 525 won't crank. How do you diagnose if it's power or the starter?

Tried the "other key". Tried jump starting (even though the battery seems fine, lights all work, all gauges, headlights, high beams, stereo. No indication of a weak battery.)
So, to get power to the starter you have
a) direct power to the solenoid from the battery
b) CAS (car access system)
As I understand it if the brake pedal switch or the neutral start switch or the start button are defective, you will get a no crank condition.
However, if there is power to the solenoid from the CAS connector during the "start" mode, it's the solenoid or starter.
Since the starter is pretty much inaccessible under the intake (remove air box, remove microfilter housings, remove ignition coil cover, remove intake mani...) is there a way to diagnose the issue without tearing the top off the engine?

[93 525 Paul]

From bimmerforums
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Starters do not normally go out on BMW. I may have done 5 in 8 years as a tech. My shop may have done 10 in the last 5 years.

[myles]

I've had 2 out of my 3 BMWs have the starter fail, so it does happen.

[Tiger]

Generically speaking, there should be a remote wire that you can hook up a remote starter to trigger the solenoid. I am not even sure if they do that today. Maybe they do that through their scanner. Do some google about this.

Other thing I can think of is check your fuse and starter relay to see if it is bad.

You really do need a OBD CAN scanner to check modern cars. Since you have many BMW in family... invest in a dedicated BMW OBD CAN scanner... probably laptop version. Make sure you know what features you are getting with the scanner to see if it will help you diagnose the problem. MIL does not have to be on to have errors.

[genphreak]

Its most likely to be a DWA fault due to an open door or some sensor.

Always check, if you get no crank or no fire that the car is not suffering DWA problem- eg locked for example: I've had a faulty microswitch allow me to open the front door but when it wouldn't start I noticed all the other doors were locked... huh?

Just cycled the locks and the engine started... the scanner will tell all- it will even log all the events making it easier to pinpoint the cause (I hope)

[93 525 Paul]

thanks one and all. After much thought, reading and some discussions with the wife, I realized that everything pointed at the starter. I recalled that the car had always "slow cranked" particularly in comparison to the E34 and the 550i. The solenoid did make a noise when the start button was pushed. It really seemed it was the starter.
Even though I hadn't towed it anywhere to have it scanned, I figured my labor is free so I took a shot at it and pulled the intake and yanked the starter. If you think pulling an M50TU intake is a PITA, try the M54. Pure joy.
Bench tested the starter motor and verified it is bad. I'd be pissed if it turned out to be something else.
The brushes on the positive side of the motor were toast. Melted into the brush holders.

[93 525 Paul]

All together now and it cranks much faster than the original starter did over the last 50,000 miles.
Got the Bosch premium "black box" (Bosch-rebuilt) starter and am glad I did.

[Tiger]

Had a similar experience on my 94 540i... original starter turns engine over 'normally' but I think is slower and eats batteries... batteries just cannot last on that car. I swapped it out with a much newer model used starter and was like twice as fast. Now battery last far longer than I would ever think is possible... 8+ years.

Keeping the battery conditioned with a smart battery charger really does extends battery life... cost very little to charge it up... one time expense for smart battery charger around $70 range.

[93 525 Paul]

The original battery in this car only lasted 5 years and I attribute it to the bad original starter. Agree on the smart charger.
On my reassembly of the E60 I thought I was careful but obviously not. It was occasionally idling poorly and the CEL (oddly a "Service Engine Soon' light on the E60) went on. Had visions of injector issues or a vacuum leak at the head. Thought back through my careful cleaning of the injectors with alcohol and clean room wipes, the new injector o-rings, the careful cleaning of the injector bores, the new "profile gaskets" in the intake, etc...
So before going too far I pulled the air filter box, the intake elbow and cleaned the throttle blade and bore (it was a bit gummy) cleaned the intake elbow sealing surfaces, super carefully installed everything and tightened the clamps really tightly.
Woot woot! No CEL (SES?) no odd idle and I'm duck dynasty happy happy happy.

[genphreak]

Nice- I bet you're happy to have it nailed.

Was it oil in the intake of the e60? What was the gum?

[93 525 Paul]

I just assumed it was the typical black build up on higher mileage cars. I don't know the dynamics of how the inside of the intake and the TB get that buildup but I've seen it in every FI car I've torn into. I looked around a bit on the web just now and it's described as carbon build up or in one case, "accumulated carbon build-up, dirt and gasoline gum over many miles of driving can cause a rough idle..."
Mine was probably an incorrectly installed boot but I wondered about the TB since the car acted like sometimes the throttle was closing too far. So I cracked open the throttle blade and stuck my finger in there and the gummy build up seemed thick enough that there was a ridge around the inside bore of the TB right where the blade closed. So I went to my clean room wipes and got that part of the bore super clean. I know shops do a thorough machine based intake soak/cleaning but since the car was getting excellent mileage and running fine except for the occasional idle stumble, I didn't want to go too far down that road.
HTH

[genphreak]

I just assumed it was the typical black build up on higher mileage cars. I don't know the dynamics of how the inside of the intake and the TB get that buildup but I've seen it in every FI car I've torn into...
HTH

Ah I see. I think its more combustion by-products that are re-circulated by the PCV system, but regardless, good to clean the TB every now and then, no doubt. A physical clean is always best, I suspect that chemical cleans are just the lazy way of doing the same thing, though they may help to clear put old pipes- not that anyone would not be replacing shitty old hoses on a performance driving machine like the ol' e34!