Starting trouble

KRS M3 · 01-24-2022, 07:07 AM

Car won't start but jumps starts from another car or portable lithium battery pack with no issue. Runs fine and everything works. Car ran for almost 30 minutes. turned off and won't restart. No battery light, no increased discharge warning. Battery was replaced 1.5yr ago. had the battery cable recall done less than a month ago. Car started multiple times with no issues on Saturday and then Sunday no go. lights, dash, idrive all come on like normal but call doesn't turn over until you jump it. where should I look for possible issue?

Helmsman · 01-24-2022, 07:19 AM

Measured voltage?

With junp you mean pushed to start or cabled from other car? If the former I guess startmotor is worth checking.

happydude · 01-24-2022, 07:50 AM

Perhaps the alternator? When mine failed I had a code on my foxwell that was “missing alternator” or something but also was working intermittently before failing.

dpaul · 01-28-2022, 09:27 AM

The simplest explanation is a bad ground strap.

I'll assume that when you placed the jumper cables, the negative was clamped to the engine block somewhere. If so, try jumping again but putting the negative somewhere on the chassis. If it fails to crank that way, your ground strap is the problem.

Rino924 · 01-28-2022, 09:35 AM

Check my thread, kind of have the same thing going on.

You're in PA, so I assume the weather is pretty cold as well?

01-24-2022, 07:07 AM	#1
KRS M3 Registered 0 Rep 2 Posts Drives: BMW M3 Join Date: Nov 2021 Location: PA iTrader: (0)	Starting trouble Car won't start but jumps starts from another car or portable lithium battery pack with no issue. Runs fine and everything works. Car ran for almost 30 minutes. turned off and won't restart. No battery light, no increased discharge warning. Battery was replaced 1.5yr ago. had the battery cable recall done less than a month ago. Car started multiple times with no issues on Saturday and then Sunday no go. lights, dash, idrive all come on like normal but call doesn't turn over until you jump it. where should I look for possible issue? Last edited by KRS M3; 01-24-2022 at 07:25 AM..
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01-24-2022, 07:19 AM	#2
Helmsman Major General 4440 Rep 7,100 Posts Drives: 2011 AW E90 M3 ZCP Join Date: Mar 2014 Location: Stockholm, Sweden iTrader: (0)	Measured voltage? With junp you mean pushed to start or cabled from other car? If the former I guess startmotor is worth checking.
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01-24-2022, 07:50 AM	#3
happydude Second Lieutenant 135 Rep 234 Posts Drives: E92 M3 / F15 X5 35d Join Date: Oct 2018 Location: TX iTrader: (0)	Perhaps the alternator? When mine failed I had a code on my foxwell that was “missing alternator” or something but also was working intermittently before failing.
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01-28-2022, 09:27 AM	#4
dpaul Lieutenant Colonel 654 Rep 1,893 Posts Drives: 2009 E90 335xi, 2011 E93 M3 Join Date: Dec 2012 Location: Boston iTrader: (3)	The simplest explanation is a bad ground strap. I'll assume that when you placed the jumper cables, the negative was clamped to the engine block somewhere. If so, try jumping again but putting the negative somewhere on the chassis. If it fails to crank that way, your ground strap is the problem.
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01-28-2022, 09:35 AM	#5
Rino924 Second Lieutenant 410 Rep 276 Posts Drives: 2009 E90 M3 Join Date: May 2012 Location: Indiana iTrader: (0)	Check my thread, kind of have the same thing going on. You're in PA, so I assume the weather is pretty cold as well?
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