[mountaineer10]

Hey all, I'm experiencing some random hesitation when starting my unmodified 2016 340i with 60k miles. When i press the start button, the car will start to crank very briefly, hesitate for about 1/2 second then start up like normal. I've had it happen during cold starts and after a long highway drives. It starts normally 90-95% of the time but this seems to be getting more frequent.

I'll be getting my battery tested this weekend but i don't think that's the issue. I found some similar, but not the same, issues on this forum where a grounding strap was broken or corroded. Has anyone experienced this? If this is the issue, does anyone know the part number and location for the engine grounding strap?

I'll be doing routine maintenance this weekend and if the grounding strap is a possible issue, I might just order it and go from there.

[B58]

More than likely your injector(s) are leaking. I had a rough hesitation start up when it was cold and warm until my cylinder walls got scored up. I'm not saying this can be the case, but it's well possible and just be careful. Its cheap insurance to drop in 6 injectors with the mileage you're at as a preventative maintenance. It could also be a weak high pressure fuel pump. Lots of things can cause a hesitation start up and it's best to have it checked out by someone that actually knows about bmws and has worked on the B58.

[mountaineer10]

Originally Posted by B58

More than likely your injector(s) are leaking. I had a rough hesitation start up when it was cold and warm until my cylinder walls got scored up. I'm not saying this can be the case, but it's well possible and just be careful. Its cheap insurance to drop in 6 injectors with the mileage you're at as a preventative maintenance. It could also be a weak high pressure fuel pump. Lots of things can cause a hesitation start up and it's best to have it checked out by someone that actually knows about bmws and has worked on the B58.

Thanks. I'll add leaking injectors and HPFP to my list of things to check. Never thought to consider injectors or HPFP since it doesn't sound like a fuel issue. Also never thought they would go out as early as 60k miles. My previous BMWs and Audis never had these fail at even twice the mileage.

[Skyhigh]

Can you make and post a video of the phenomena? Would be interesting and useful to actually see/hear what it is doing. This will allow others who had similar behaviour to recognise it easier.

[mountaineer10]

It turned out that the battery was bad. It was strange to me because i hadn't experienced a battery going bad gradually over several weeks while still working perfectly 95% of the time. Guess I was used to old school technology where batteries seemed to go bad with little notice.

[cfm56d7b]

Originally Posted by mountaineer10

It turned out that the battery was bad. It was strange to me because i hadn't experienced a battery going bad gradually over several weeks while still working perfectly 95% of the time. Guess I was used to old school technology where batteries seemed to go bad with little notice.

Thanks for the update. Replacing the battery costs quite a bit less than replacing HPFP and / or injectors.

[markoz28]

I had the same problem with the same remedy. The Car would take an extra second or 2 to crank over. Got checked out by BMW stealership and about $600 later had a new battery and everything was like clock work again.

[Skyhigh]

But is it a classic slow starter noise or does it sound normal, just takes extra attempts and time to crank?

[WrxToBeamerGuy]

Originally Posted by mountaineer10

It turned out that the battery was bad. It was strange to me because i hadn't experienced a battery going bad gradually over several weeks while still working perfectly 95% of the time. Guess I was used to old school technology where batteries seemed to go bad with little notice.

Everyone should get Bimmerlink with an OBD adapter so you can check things on your phone. That way you can do some preliminary testing yourself. I imagine the battery charge would have showed as pretty low on Bimmerlink.

[G.Newt]

2016 with 60k miles and your battery lasted this long? Mine went out around 45kish or so last year lol. I think replacing it every 4 years/40k as preventative maintenance is a good idea.

[WrxToBeamerGuy]

Originally Posted by G.Newt

2016 with 60k miles and your battery lasted this long? Mine went out around 45kish or so last year lol. I think replacing it every 4 years/40k as preventative maintenance is a good idea.

Replaced mine at 65k miles after it started discharging too fast.

[mountaineer10]

Originally Posted by Skyhigh

But is it a classic slow starter noise or does it sound normal, just takes extra attempts and time to crank?

For me, it started normally most of the time. Maybe 1 out of 20 attempts or so, it would start to crank for a split second. Then, it would stop and go silent like someone put a video on pause for a half second, then continue to crank and start up like normal.

Then it would go back to normal starting like usual until about a week later, it would do the "video on pause" thing again. It would usually do this on the first crank after a 30+ minute highway drive (like after stopping at a convenience store).

This is why it stumped me. I expected the battery would be fully charged after a long highway drive.

[mountaineer10]

Originally Posted by G.Newt

2016 with 60k miles and your battery lasted this long? Mine went out around 45kish or so last year lol. I think replacing it every 4 years/40k as preventative maintenance is a good idea.

Oh man. I guess I got lucky. My car mostly sat around for a year or so during 2020-2021.

[Fizzius]

Interesting... I have a 2016 340i xdrive with 84k on it and I am the 3rd owner. Car was always serviced at the dealership that I purchased from and done all items that were recommended including oil every 10k. However, I do not remember seeing that the battery has ever been replaced. If what you guys are saying is true, I may be looking at replacing before winter hits here in the midwest.