S54 long cold cranking

Ascanio · 10-13-2021, 06:42 AM

No codes. No rough idling. Car runs smooth once started.

But. When cold it takes long to crank.
When I changed the battery it seemed to go away, but now it’s getting worse and worse (I will have to get a battery tender because I’m starting to hear the cranking become slower also, afraid I’m using more energy than I am recharging during commutes).

I am using the Z4M for commuting to work (4 miles), and driving slow.

I know there are threads about long cranking but they appear to be about warm/hot cranking, not cold.

Anybody had this issue?

bwright657 · 10-13-2021, 08:55 AM

My guess is that the combination of cold weather and short trips is putting extra stress on the battery. Since you're not going far, the alternator isn't running long enough to build the battery charge back up. A battery tender would definitely help and going out for longer drives would too. If you continue to see an issue after longer drives, the alternator might be on its way out.

Ascanio · 10-13-2021, 08:56 AM

OK thanks!
Will get a tender now.

BTW I have a “tender to Z4M” hahahah
My UNAGI electric scooter fits perfectly in the boot!

10-13-2021, 06:42 AM	#1
Ascanio Private 13 Rep 69 Posts Drives: Mazda MX-5, BMW Z4 M Roadster Join Date: Dec 2013 Location: Savannah, GA iTrader: (0)	S54 long cold cranking No codes. No rough idling. Car runs smooth once started. But. When cold it takes long to crank. When I changed the battery it seemed to go away, but now it’s getting worse and worse (I will have to get a battery tender because I’m starting to hear the cranking become slower also, afraid I’m using more energy than I am recharging during commutes). I am using the Z4M for commuting to work (4 miles), and driving slow. I know there are threads about long cranking but they appear to be about warm/hot cranking, not cold. Anybody had this issue?
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10-13-2021, 08:55 AM	#2
bwright657 Second Lieutenant 258 Rep 208 Posts Drives: 08 Z4 M Coupe Join Date: Apr 2019 Location: Greenville, SC iTrader: (1) Garage List 2008 BMW Z4M Coupe [9.50] 1999 Mazda Miata [0.00]	My guess is that the combination of cold weather and short trips is putting extra stress on the battery. Since you're not going far, the alternator isn't running long enough to build the battery charge back up. A battery tender would definitely help and going out for longer drives would too. If you continue to see an issue after longer drives, the alternator might be on its way out. __________________ '08 Z4M Coupe \| Space Grey/Imola Red Extended/Carbon Leather \| Eventuri Intake \| Strömung Exhaust \| Strong Strut Front/Rear Braces \| 19" E46 M3 ZCP Wheels
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10-13-2021, 08:56 AM	#3
Ascanio Private 13 Rep 69 Posts Drives: Mazda MX-5, BMW Z4 M Roadster Join Date: Dec 2013 Location: Savannah, GA iTrader: (0)	OK thanks! Will get a tender now. BTW I have a “tender to Z4M” hahahah My UNAGI electric scooter fits perfectly in the boot!
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