Z4M Weak Start

mziggy16 · 12-18-2018, 09:51 AM

Hey All -

I've had the Z napping for the past few weeks while the weather was a little slick. I didn't do any storage prep, other than a full tank with some Sta-bil, just in case it rested for longer than a few weeks.

Anyway, when I turned the key over the start was pretty weak and labored. Once it fired up the clock had been reset.

Is this battery related? Should I have the battery disconnected, trickle charger, etc., or is this indicative of anything else?

Thanks!

-Mike

XMetal · 12-18-2018, 09:56 AM

Sounds like it. I think you already know the answer, but if you don't plan on driving it for a while, then have the battery disconnected. Otherwise, just keep it trickle charge.

The HACK · 12-18-2018, 09:59 AM

If it was on a trickle charger, and clock and a variety of settings reset during the hard crank, it's time (IMO) to replace the battery. It's not supplying enough cold crank power to turn over and the resulting voltage drop reset the clock.

My MZ4 Coupe is 12 years old, on its 2nd battery going on about 7 years now. It gets cranked once every week for some joy rides now, or if my wife's diesel is blocking the Corvette (JFC I've gone FULL redneck now). I leave it on a CTEK overnight once a week, and it cranks over fine, but that first crank in the morning always cranks a little harder.

There's been a few times when I didn't leave it on a trickle charger, and after about 4-5 days the car would have very similar symptoms. Very hard and long first crank, and afterwards the windows (auto up and down), clock, trip, and a variety of stored information reset. I figure 7 years on an AGM is pretty much pushing my luck and will probably replace sometime next year.

Your case seems worse, that the battery has just enough voltage to barely crank over when cold even on a trickle charger.

mziggy16 · 12-18-2018, 10:35 AM

Sorry if it wasn't clear - it was not on a trickle charger.

Thanks for the replies!

KevinC · 12-18-2018, 11:49 AM

Put it on a Battery Tender. I'm surprised it turns over at all after "a few weeks" this time of year.

garz747 · 12-18-2018, 07:37 PM

The Z4m sends out a bluetooth signal if the doors arent locked. Even then shes got to be on a maintenance charger or the battery depletes after a few weeks. It seems to have a higher standby draw than my other bimmer.

KevinC · 12-18-2018, 11:02 PM

Quote:

Originally Posted by garz747

The Z4m sends out a bluetooth signal if the doors arent locked.

No, it doesn't. Non-Premium Package cars don't even have Bluetooth. Where did you get that idea??

StickMon · 12-18-2018, 11:32 PM

^WHS, or at least, it's not supposed to.
My phone disconnects as soon as I turn the car off, long before I lock the doors.
But one day last week after I shut the car off the white lights in the speedo and tach were still on.
Turned it on/off and they went out.
No telling what the car may forget to turn off.

garz747 · 12-19-2018, 07:21 PM

Yes- it was posted on this forum a couple years back that some owners had trouble with radio/bluetooth failure to disconnect which ran the battery down from parasitic drain.

bosstones · 12-20-2018, 09:36 PM

Were the doors locked or unlocked during its slumber. On my original factory battery, I stored it every winter w/o starting it or having it on a trickle charger for the first 5-6 years and it started like a champ in the spring. Some others had similar experiences whereas others did not. The only possible common thread might have been the former folks leaving the doors locked vs the latter not.

That said, I do keep it on a trickle charger now. I have only had an issue starting the car if my phone was plugged in the charger prior to starting the car...which is still weird to me.

mziggy16 · 12-21-2018, 10:50 AM

Quote:

Originally Posted by bosstones

Were the doors locked or unlocked during its slumber. On my original factory battery, I stored it every winter w/o starting it or having it on a trickle charger for the first 5-6 years and it started like a champ in the spring. Some others had similar experiences whereas others did not. The only possible common thread might have been the former folks leaving the doors locked vs the latter not.

That said, I do keep it on a trickle charger now. I have only had an issue starting the car if my phone was plugged in the charger prior to starting the car...which is still weird to me.

Locked. I'm picking up a trickle charger today, so I should be all set now. Thanks for all the replies!

mziggy16 · 01-11-2019, 09:12 AM

If I just disconnect the positive and negative battery terminals in the trunk, do I need to remove the battery or can just leave the battery in place and make sure the terminals can't come in contact with the battery?

Or, should I be removing the battery and placing it on a trickle charger elsewhere?

Just want to make sure I don't have issues with firing it up if it ends up sitting for a few weeks again.

It's in a shared garage at a condo, so running a cord across the floor for the trickle charger isn't as easy as if it was in my own garage.

garz747 · 01-11-2019, 09:47 AM

If u cannot hook up a maintenance charger just remove the negative terminal from the battery.

12-18-2018, 09:51 AM	#1
mziggy16 Private First Class 31 Rep 135 Posts Drives: '07 Z4MC, '01 911 C4 Cabriolet Join Date: Nov 2011 Location: St. Louis, MO iTrader: (1)	Z4M Weak Start Hey All - I've had the Z napping for the past few weeks while the weather was a little slick. I didn't do any storage prep, other than a full tank with some Sta-bil, just in case it rested for longer than a few weeks. Anyway, when I turned the key over the start was pretty weak and labored. Once it fired up the clock had been reset. Is this battery related? Should I have the battery disconnected, trickle charger, etc., or is this indicative of anything else? Thanks! -Mike __________________ CURRENT: '07 Z4 M Coupe /// ‘01 911 C4 Cab SOLD: '06 330i / '07 335i / '07 X5 4.8 / '13 335i
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12-18-2018, 09:56 AM	#2
XMetal Colonel 1125 Rep 2,860 Posts Drives: Anything Join Date: Apr 2010 Location: SoCal iTrader: (0) Garage List 2008 Z4M Coupe [10.00] 2018 Audi S3 [0.00] 2004 X5 [8.50]	Sounds like it. I think you already know the answer, but if you don't plan on driving it for a while, then have the battery disconnected. Otherwise, just keep it trickle charge.
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12-18-2018, 09:59 AM	#3
The HACK Midlife Crises Racing Silent but Deadly Class 1819 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	If it was on a trickle charger, and clock and a variety of settings reset during the hard crank, it's time (IMO) to replace the battery. It's not supplying enough cold crank power to turn over and the resulting voltage drop reset the clock. My MZ4 Coupe is 12 years old, on its 2nd battery going on about 7 years now. It gets cranked once every week for some joy rides now, or if my wife's diesel is blocking the Corvette (JFC I've gone FULL redneck now). I leave it on a CTEK overnight once a week, and it cranks over fine, but that first crank in the morning always cranks a little harder. There's been a few times when I didn't leave it on a trickle charger, and after about 4-5 days the car would have very similar symptoms. Very hard and long first crank, and afterwards the windows (auto up and down), clock, trip, and a variety of stored information reset. I figure 7 years on an AGM is pretty much pushing my luck and will probably replace sometime next year. Your case seems worse, that the battery has just enough voltage to barely crank over when cold even on a trickle charger. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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12-18-2018, 10:35 AM	#4
mziggy16 Private First Class 31 Rep 135 Posts Drives: '07 Z4MC, '01 911 C4 Cabriolet Join Date: Nov 2011 Location: St. Louis, MO iTrader: (1)	Sorry if it wasn't clear - it was not on a trickle charger. Thanks for the replies! __________________ CURRENT: '07 Z4 M Coupe /// ‘01 911 C4 Cab SOLD: '06 330i / '07 335i / '07 X5 4.8 / '13 335i
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12-18-2018, 11:49 AM	#5
KevinC your average JAMF 3085 Rep 4,088 Posts Drives: '21 M2 Comp, '19 Golf R Join Date: Oct 2005 Location: Cochise County, AZ iTrader: (0) Garage List 2019 VW Golf R [0.00] 2021 BMW M2 Competi ... [0.00]	Put it on a Battery Tender. I'm surprised it turns over at all after "a few weeks" this time of year. __________________ '21 M2 Comp '19 Golf R
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12-18-2018, 07:37 PM	#6
garz747 Captain 286 Rep 678 Posts Drives: 07 Z4MC 01 330i 18 X3 M40i Join Date: Jul 2015 Location: Toronto iTrader: (0)	The Z4m sends out a bluetooth signal if the doors arent locked. Even then shes got to be on a maintenance charger or the battery depletes after a few weeks. It seems to have a higher standby draw than my other bimmer.
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12-18-2018, 11:32 PM	#8
StickMon My other car is on Mars 636 Rep 3,124 Posts Drives: 2006 MR Join Date: Feb 2011 Location: Lo-Cal iTrader: (1)	^WHS, or at least, it's not supposed to. My phone disconnects as soon as I turn the car off, long before I lock the doors. But one day last week after I shut the car off the white lights in the speedo and tach were still on. Turned it on/off and they went out. No telling what the car may forget to turn off. __________________ Warning: May contain traces of nuts.
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12-19-2018, 07:21 PM	#9
garz747 Captain 286 Rep 678 Posts Drives: 07 Z4MC 01 330i 18 X3 M40i Join Date: Jul 2015 Location: Toronto iTrader: (0)	Yes- it was posted on this forum a couple years back that some owners had trouble with radio/bluetooth failure to disconnect which ran the battery down from parasitic drain.
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12-20-2018, 09:36 PM	#10
bosstones Lieutenant Colonel 1154 Rep 1,543 Posts Drives: o_0 Join Date: Mar 2008 Location: Suburbia iTrader: (0)	Were the doors locked or unlocked during its slumber. On my original factory battery, I stored it every winter w/o starting it or having it on a trickle charger for the first 5-6 years and it started like a champ in the spring. Some others had similar experiences whereas others did not. The only possible common thread might have been the former folks leaving the doors locked vs the latter not. That said, I do keep it on a trickle charger now. I have only had an issue starting the car if my phone was plugged in the charger prior to starting the car...which is still weird to me. __________________ - Jeff bosstones' flickr
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01-11-2019, 09:12 AM	#12
mziggy16 Private First Class 31 Rep 135 Posts Drives: '07 Z4MC, '01 911 C4 Cabriolet Join Date: Nov 2011 Location: St. Louis, MO iTrader: (1)	If I just disconnect the positive and negative battery terminals in the trunk, do I need to remove the battery or can just leave the battery in place and make sure the terminals can't come in contact with the battery? Or, should I be removing the battery and placing it on a trickle charger elsewhere? Just want to make sure I don't have issues with firing it up if it ends up sitting for a few weeks again. It's in a shared garage at a condo, so running a cord across the floor for the trickle charger isn't as easy as if it was in my own garage. __________________ CURRENT: '07 Z4 M Coupe /// ‘01 911 C4 Cab SOLD: '06 330i / '07 335i / '07 X5 4.8 / '13 335i
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01-11-2019, 09:47 AM	#13
garz747 Captain 286 Rep 678 Posts Drives: 07 Z4MC 01 330i 18 X3 M40i Join Date: Jul 2015 Location: Toronto iTrader: (0)	If u cannot hook up a maintenance charger just remove the negative terminal from the battery.
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