06 BMW Z4 3.0si Slow/Rough Start

bimmertt · 01-25-2014, 07:38 PM

The starter has been acting up lately. Not sure if it is the cold weather we are experiencing, the battery, or the starter. Usually the crank is very fast, but now there is a hesitation. Any ideas?

jeebus87 · 01-25-2014, 10:00 PM

Sounds like mine. It always take a split second longer when it's really cold.

thelinux · 01-27-2014, 03:22 AM

I am pretty sure it's the battery going bad. How old is your battery?

gas-can · 01-27-2014, 07:25 AM

Agree on the battery. Mine had the original battery and everything was perfect until the cold came in this time, then it was slow, just like yours. Replaced it and all is well again.

Also difficult to say with the video, but that screeching noise after the start may indicate that your starter bendix may need to be regreased. What may be happening is the original grease is gone/damaged and the bendix is slow to retract the gear from the flywheel after the start, so it hangs around a bit longer than necessary, causing the loud screech. Recommend regreasing that when you can or you may need to do a starter replacement before soon.

-gc

bimmertt · 02-10-2014, 07:46 PM

Just to update this thread, it turned out to be the battery. It officially died this morning.

There were some differing opinions on what battery to use. I purchased a group 48/H6 as that is the size that I pulled out of the car. It fit perfectly.

bimmertt · 10-18-2015, 08:54 PM

Bumping my old thread

Weather is getting cooler and the annoying grinding noise is back when starting the car. You can hear it in the video above. I read that something in the starter needs to be lubricated. Is there a DIY for this anywhere?

Daemonblitz · 10-19-2015, 06:51 AM

Quote:

Originally Posted by bimmertt

Bumping my old thread

Weather is getting cooler and the annoying grinding noise is back when starting the car. You can hear it in the video above. I read that something in the starter needs to be lubricated. Is there a DIY for this anywhere?

I don't know how often you drive your car but if it sits for long periods of time and/or only driven short distances, it may just be the battery going low again. If that's the case I'd recommend a trickle charger.

Clearancediver · 10-19-2015, 01:48 PM

If you are removing starter to lubricate/repair starter solenoid... I would just replace the starter with a new one instead...

On my '04 3.0i two bolts secure starter. I removed the air ducting/sound generator plenums/ducting from that area to access and provide working space to remove/replace starter from engine compartment... Pretty straight forward after that to get my hands in to access the bolts and starter power wiring.

Diesel_d66 · 10-22-2015, 08:57 AM

related question: sometimes (varies on time of day) my car wont start at all when i insert the key and quickly turn it to ignition, trying it again the second time always cranks the car and turns it on. Should I be turning to key to 'on', waiting, then turning to ignition?

I do hear a faint pumping sound when I turn the key to on in the mornings prior to the ignition. Any idea what that is?

chickdr · 10-22-2015, 09:05 AM

Quote:

Originally Posted by Diesel_d66

related question: sometimes (varies on time of day) my car wont start at all when i insert the key and quickly turn it to ignition, trying it again the second time always cranks the car and turns it on. Should I be turning to key to 'on', waiting, then turning to ignition?

I do hear a faint pumping sound when I turn the key to on in the mornings prior to the ignition. Any idea what that is?

I believe the sound is the fuel pump. Ideally you should wait until this stops(go to the first click and wait for the sound to stop) then turn and start. You could also have an issue with your starter(a fairly common failure point in the Z4).

gas-can · 10-22-2015, 08:15 PM

My starter started screeching at startup when it was cold so I took it apart today.

Problem: The bell housing collects clutch dust from the clutch/flywheel. This is the same housing that the starter sits in. What happens in the long term is that the clutch dust gets attracted to the starter pinion gear/shaft. It starts to impede the free movement and the gear stays attached to the flywheel for too long. Result is a screech at startup.

In this case, I retract my earlier statement about regreasing - I highly recommend against regreasing this shaft/gear since it will just cause the clutch dust to cake on even stronger/faster. Instead, I recommend stripping the starter and solenoid housing and cleaning everything up.

Here are some pics to help you see what it looks like inside

01-25-2014, 07:38 PM	#1
bimmertt Lieutenant Colonel 93 Rep 1,794 Posts Drives: 2007 e92 335i Join Date: Nov 2008 Location: Earth iTrader: (7)	06 BMW Z4 3.0si Slow/Rough Start The starter has been acting up lately. Not sure if it is the cold weather we are experiencing, the battery, or the starter. Usually the crank is very fast, but now there is a hesitation. Any ideas?
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01-25-2014, 10:00 PM	#2
jeebus87 Second Lieutenant 32 Rep 292 Posts Drives: '11 atacama yellow Z4 35i Join Date: Oct 2012 Location: USA iTrader: (4)	Sounds like mine. It always take a split second longer when it's really cold.
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01-27-2014, 03:22 AM	#3
thelinux Private First Class 14 Rep 155 Posts Drives: 2008 Z4 3si Join Date: Feb 2013 Location: Irvine, CA iTrader: (0)	I am pretty sure it's the battery going bad. How old is your battery?
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01-27-2014, 07:25 AM	#4
gas-can Second Lieutenant 25 Rep 204 Posts Drives: 2006 3.0i Roadster Join Date: Oct 2012 Location: USA iTrader: (0)	Agree on the battery. Mine had the original battery and everything was perfect until the cold came in this time, then it was slow, just like yours. Replaced it and all is well again. Also difficult to say with the video, but that screeching noise after the start may indicate that your starter bendix may need to be regreased. What may be happening is the original grease is gone/damaged and the bendix is slow to retract the gear from the flywheel after the start, so it hangs around a bit longer than necessary, causing the loud screech. Recommend regreasing that when you can or you may need to do a starter replacement before soon. -gc
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02-10-2014, 07:46 PM	#5
bimmertt Lieutenant Colonel 93 Rep 1,794 Posts Drives: 2007 e92 335i Join Date: Nov 2008 Location: Earth iTrader: (7)	Just to update this thread, it turned out to be the battery. It officially died this morning. There were some differing opinions on what battery to use. I purchased a group 48/H6 as that is the size that I pulled out of the car. It fit perfectly.
	Appreciate 0 Quote

10-18-2015, 08:54 PM	#6
bimmertt Lieutenant Colonel 93 Rep 1,794 Posts Drives: 2007 e92 335i Join Date: Nov 2008 Location: Earth iTrader: (7)	Bumping my old thread Weather is getting cooler and the annoying grinding noise is back when starting the car. You can hear it in the video above. I read that something in the starter needs to be lubricated. Is there a DIY for this anywhere?
	Appreciate 0 Quote

10-19-2015, 01:48 PM	#8
Clearancediver Lieutenant 90 Rep 406 Posts Drives: 2004 Z4 Join Date: Oct 2012 Location: Victoria, BC Canada iTrader: (0)	If you are removing starter to lubricate/repair starter solenoid... I would just replace the starter with a new one instead... On my '04 3.0i two bolts secure starter. I removed the air ducting/sound generator plenums/ducting from that area to access and provide working space to remove/replace starter from engine compartment... Pretty straight forward after that to get my hands in to access the bolts and starter power wiring. __________________ Sent from my smart phone...
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10-22-2015, 08:57 AM	#9
Diesel_d66 Private 8 Rep 71 Posts Drives: '07 MR Join Date: Oct 2013 Location: Baltimore iTrader: (0)	related question: sometimes (varies on time of day) my car wont start at all when i insert the key and quickly turn it to ignition, trying it again the second time always cranks the car and turns it on. Should I be turning to key to 'on', waiting, then turning to ignition? I do hear a faint pumping sound when I turn the key to on in the mornings prior to the ignition. Any idea what that is?
	Appreciate 0 Quote

10-22-2015, 08:15 PM	#11
gas-can Second Lieutenant 25 Rep 204 Posts Drives: 2006 3.0i Roadster Join Date: Oct 2012 Location: USA iTrader: (0)	My starter started screeching at startup when it was cold so I took it apart today. Problem: The bell housing collects clutch dust from the clutch/flywheel. This is the same housing that the starter sits in. What happens in the long term is that the clutch dust gets attracted to the starter pinion gear/shaft. It starts to impede the free movement and the gear stays attached to the flywheel for too long. Result is a screech at startup. In this case, I retract my earlier statement about regreasing - I highly recommend against regreasing this shaft/gear since it will just cause the clutch dust to cake on even stronger/faster. Instead, I recommend stripping the starter and solenoid housing and cleaning everything up. Here are some pics to help you see what it looks like inside
	Appreciate 0 Quote