135i Starting Issues

[IamHere]

This is the first real issue I've had with my '13 135i with 110k miles.

A few weeks ago there was a little hesitation when I started it but it started up on the second try and I kind of forgot about it.

It happened again and this time it didn't start. I could hear the starter turn once or twice but not enough to catch. No big deal since I was on a hill, and a quick push start got me home.

I stopped by a garage across from my work to test the battery. They loaded it down and it looked on the edge of ok. They were able to jump it (using the terminal in the engine bay) and I stopped by the auto parts store and grabbed a replacement.

After installing the replacement and leaving it on a charger overnight it still wouldn't start. Another push start...

Since it wasn't the battery I assumed it would be the starter. I had my local garage put in a replacement. It started ~10 times before the hesitation came back and now I'm push starting my car again.

Any ideas on what I should check next???

Could it be the resistance in the wiring between the battery and the starter? This explains why we could jump it from the engine bay and not from the battery directly (at the time we thought it was a bad connection in the trunk).

Any help is greatly appreciated before I start throwing more money at thing that aren't the actual problem.


Update: I just tried to meter it during the starting and both the in the engine bay terminal and directly at the battery the voltage only dipped to 11.6v when I tried to start it.

[TheCaptain]

Check for any fault codes. And don't forget to code in the new battery.

[IamHere]

Originally Posted by TheCaptain

Check for any fault codes. And don't forget to code in the new battery.

I checked it with a generic ODBII scanner and there were no codes.

At this point I feel like it isn't a battery issue so I'll put the original battery back in once I find the root cause so I shouldn't have to recode for the battery.

[IamHere]

The next thing I just checked was the ground strap. Theoretically if that was flaky it could show similar symptoms.

The engine bay strap looks fine.


I attached a jumper cable from the battery ground directly to the ground strap bolt and still nothing.

[HyeWarrior]

I've had a very similar experience lately. Except my mechanic claimed the new starter he initially installed didn't work because I guess it was faulty. They installed a new one and now it starts fine, but I'm not convinced it's fixed. Personally I believe it was the 12v cable going to the starter from the battery terminal. If my car fails again, I know for sure that's the problem. I did come across a thread on here last week where someone went through exactly what I did, except it was in fact the 12v wire. Apparently it corroded underneath the insulation so it was impossible to tell from just looking at it.

In your case and possibly mine, it HAS to either be that or the ground

[jlc45]

This used to be a very common problem on all makes of cars.
A ground strap may look OK but in fact it is corroded or lacking continuity.
There may also be a second or third grounding cable from the transmission to the engine or to the frame. You may have to remove the protective plastic shield under the car to see this. A mechanic friend of mine was telling me about BMWs that would not start having this problem and being misdiagnosed to the tune of many $$$$$$$.
Jim

[mr.fabulous]

My car has always cranked v-e-r-y slowly. There was no change when I replaced the battery 2yrs ago, there is no change after it comes off the charger (I charge the thing once a week, reference threads from a few years ago about taking nothing but short trips and "intelligent alternator control"). It seems to get worse after a few starts (say, if I make a few stops all within a mile or two of each other). It's never not started... but it will turn over once very slowly and then catch. Worries me every time I get into the thing...

[IamHere]

I haven't fixed it yet, but it looks like it is the power cable. I checked it this morning and it flexed a little too easily. The only thing holding it together was the heat shrink.

I'll have an update once the parts store opens up and I can get a new terminal.

Update: This was it. A $2 terminal fixed it. I'm back up and running.

[doublevanosrc]

Any idea what caused it to break? Time and heat? Shoddy quality??

Glad it was an easy cheap fix.

[HyeWarrior]

Originally Posted by doublevanosrc

Any idea what caused it to break? Time and heat? Shoddy quality??

Glad it was an easy cheap fix.

Probably all of the above.

Glad it got sorted out OP, did you swap out the whole cable yourself?

[ejm3]

You have a 2013 with 110k miles???

[IamHere]

Originally Posted by doublevanosrc

Any idea what caused it to break? Time and heat? Shoddy quality??

Glad it was an easy cheap fix.

There was no visible damage on the outside of the heat shrink. The only theory I can come up with is that there were a few broken strands in the cable originally causing this to be the highest resistance part in the chain. After 110k miles worth of starts it heated up and melted the rest of the strands. The ends were coated in black char when I first opened it up.

[IamHere]

Originally Posted by HyeWarrior

Probably all of the above.

Glad it got sorted out OP, did you swap out the whole cable yourself?

There was just enough slack in the cable to crimp on a new terminal and get it to reach the original mount. It is kind of a pain to get down to the starter to replace the whole cable. I'm going to keep an eye on it, and if I see any damage starting I'll go through the effort to replace the whole cable.

[IamHere]

Originally Posted by ejm3

You have a 2013 with 110k miles???

Yes, I got it in late 2012 and drive 25-30k/year. That doesn't seem too outrageous since I use to drive more like 40k/year.

[mr.fabulous]

Reference my newer thread "Damn battery is dead". Seems I have a similar problem with the same cable. I do not know where (in the cable) the break is, and as this is my only car I don't want to leave myself stranded trying to find out (it failed altogether on me yesterday in my garage, brought it back to life by jiggling the cable).

The car has always cranked slowly, and so it seems this has been decaying since I started driving it (2yrs ago).

And so the cable will get replaced. I'm tired of working on cars and so this might be my very first (in my life) visit to an Indi for a problem I can fix myself. UGH.

I hope it starts this afternoon (gym visit)

[HyeWarrior]

^ how many miles do you have?

[jlc45]

Slightly off topic, but related:
I used to fix cars as a transmission mechanic, in a former life.
We saw many auto transmission cars with floor shifters where the shifter handle was very stiff or impossible to move. Car was in some cases undriveable.
Problem was missing or corroded ground strap from engine to frame.
The car would then use the shifter cable as a ground strap which would fry the cable in a short time. Mostly Camaros and Firebirds back in the day...
But same principle holds today and is apparently a similar issue with modern bmws.
There are lots of cases where starters, batteries, spark plugs, coils etc. have been changed when the problem was really a faulty cable, usually the ground strap.
Jim

[mr.fabulous]

Seems more than one guy here has had this fail, 12427584691. Cost me $580 to replace a $77 cable (dealer, incl four day three night loaner, first time I have ever paid somebody to fix something I could have done myself, but it sure was convenient).

[yaroshti]

Im trying to locate the ground wire reference in the 1st picture, where is it located?

[Dackelone]

Originally Posted by jlc45

Slightly off topic, but related:
I used to fix cars as a transmission mechanic, in a former life.
We saw many auto transmission cars with floor shifters where the shifter handle was very stiff or impossible to move. Car was in some cases undriveable.
Problem was missing or corroded ground strap from engine to frame.
The car would then use the shifter cable as a ground strap which would fry the cable in a short time. Mostly Camaros and Firebirds back in the day...
But same principle holds today and is apparently a similar issue with modern bmws.
There are lots of cases where starters, batteries, spark plugs, coils etc. have been changed when the problem was really a faulty cable, usually the ground strap.
Jim

I've seen the same thing on VW Golf's and Jetta's... the little ground strap on the steering rack would snap off or be left off... then the engine grounds would go thru the CV joints/front drive axles. Those VC balls would become all pitted in no time. Not a cheap repair for such a minor small ground wire being left off or cut off from running over some debris.

Dack

[chris_flies]

Originally Posted by yaroshti

Im trying to locate the ground wire reference in the 1st picture, where is it located?

If I remember correctly, it's between the steering column and the motor mount on the driver's side.

[Gangplank]

Originally Posted by chris_flies

If I remember correctly, it's between the steering column and the motor mount on the driver's side.

That's where it is alright. I've been having a bit of a slow crank for a while now. Instead of push button = vroom, it's push button = whir, whir, whir-whir vroom.

Had the battery checked and it came out 12.34v and 65% charge. The car is my DD & it's only about 20min/11 miles to work, so I'm not sure if that's enough to keep it charging all the way.

I'm planning to put it on the charger over night & take it back and have it checked again next week.

So i don't think it's the grounding strap strap based on these pics. My battery is from 2015.