Cold start in sport + DCT loud clunk sound

Tonyfsu21 · 08-04-2016, 07:50 PM

I started my m3 (500 miles new) this am after sitting a couple days without driving. I cold started & immediately hit the "M1" button which I have dialed into the most aggressive settings. After shifting the car into gear and slightly pressing the gas petal the car hesitated and then a very loud clunk before moving forward. This has so far happened twice on cold start. No idea what's causing this. Anyone else experience this?

RowanBuds · 08-04-2016, 07:56 PM

I get this occasionally too, but it seems to be after I've washed the car then put it away for a few days. I just assumed it had to do with it being put away while slightly damp at the rotor/pad interface.

*edit* - I had the car at Bimmerfest East last weekend and my ride home was filled with heavy downpours. When I got home the car went right into the garage soaking wet and was parked for 2.5 days until I could wash it. When I then put it in gear and tapped the gas to back out of the garage I heard that clunk the loudest/harshest I have ever heard it. To my brain that reinforced the assumption of parked with damp braking system.

///M-er-gized · 08-04-2016, 08:11 PM

The only thing I notice is that when I first got my car, and I pushed the start button, the car started immediately.

Now when I push the start button, it takes a couple seconds. I was going to start a thread for this, but decided not to. I still might...

A couple seconds might not sound bad, but it's definitely noticeable. Also, I had an F30 335 before this, and that always started immediately too, and I never experienced any sort of delay like this.

I don't want to highjack your thread, but while we're on the subject of cold starts, I thought this might be a good opportunity to throw this out there, and maybe get some feedback...

Tonyfsu21 · 08-05-2016, 06:24 AM

Quote:

Originally Posted by RowanBuds

I get this occasionally too, but it seems to be after I've washed the car then put it away for a few days. I just assumed it had to do with it being put away while slightly damp at the rotor/pad interface.

*edit* - I had the car at Bimmerfest East last weekend and my ride home was filled with heavy downpours. When I got home the car went right into the garage soaking wet and was parked for 2.5 days until I could wash it. When I then put it in gear and tapped the gas to back out of the garage I heard that clunk the loudest/harshest I have ever heard it. To my brain that reinforced the assumption of parked with damp braking system.

I wonder about this. I keep my car outside in South Florida and I live adjacent to a waterway so the vehicle is often wet. It could also be a function of time as you mentioned your vehicle sat for more than 2 days. This only happens when I don't drive my car on a daily basis. Def a loud clunk and cause for concern.

RickFLM4 · 08-05-2016, 06:26 AM

I also live in South Florida and my car often sits for days. I don't recall hearing any loud clunks over the past year+.

TooFan328i · 08-05-2016, 06:56 AM

Do you use that handbrake? Did the noise come from the rear end?

RowanBuds · 08-05-2016, 07:06 AM

Quote:

Originally Posted by TooFan328i

Do you use that handbrake? Did the noise come from the rear end?

I am using the handbrake when this happens, and to me it does sound like it's coming from the rear.

CaryTheLabelGuy · 08-05-2016, 07:40 AM

Had it recently rained? If so, the brakes will rust really easily and the pads will stick to the rotors. When you start to move, the brakes will sometimes make a loud "clunk" as the pads release the rotors. Totally normal.

TooFan328i · 08-05-2016, 07:46 AM

Quote:

Originally Posted by CaryTheLabelGuy

Had it recently rained? If so, the brakes will rust really easily and the pads will stick to the rotors. When you start to move, the brakes will sometimes make a loud "clunk" as the pads release the rotors. Totally normal.

Exactly! Even if it doesn't rain, like when you have lots of mist/moisture, this will happen.

TooFan328i · 08-05-2016, 07:47 AM

Quote:

Originally Posted by RowanBuds

I am using the handbrake when this happens, and to me it does sound like it's coming from the rear.

Yep! Totally normal. It's the rear brake pads getting unstuck from the rotors. Look at CaryTheLabelGuy post.

Tonyfsu21 · 08-05-2016, 08:16 AM

Quote:

Originally Posted by TooFan328i

Quote:

Originally Posted by RowanBuds

I am using the handbrake when this happens, and to me it does sound like it's coming from the rear.

Yep! Totally normal. It's the rear brake pads getting unstuck from the rotors. Look at CaryTheLabelGuy post.

I don't use the handbrake at all. I normally back into my driveway and then get out of reverse and into a forward gear and power down. The display shows "P" for Park when I press the button a second time to completely power down accessories. Is it possible this vehicle is supposed to be left in the neutral position with hand brake engaged? The sound is def coming from the rear end of the car.

CaryTheLabelGuy · 08-05-2016, 08:27 AM

Quote:

Originally Posted by Tonyfsu21

I don't use the handbrake at all. I normally back into my driveway and then get out of reverse and into a forward gear and power down. The display shows "P" for Park when I press the button a second time to completely power down accessories. Is it possible this vehicle is supposed to be left in the neutral position with hand brake engaged? The sound is def coming from the rear end of the car.

First of all, you need to be using the handbrake. Second of all, you need to be using the handbrake.

But seriously, it's your brakes I'm almost 100% certain.

08-04-2016, 07:50 PM	#1
Tonyfsu21 Second Lieutenant 169 Rep 276 Posts Drives: 2011 E92 M3, Jet Black, ZCP Join Date: Mar 2012 Location: Fort Lauderdale, FL iTrader: (0)	Cold start in sport + DCT loud clunk sound I started my m3 (500 miles new) this am after sitting a couple days without driving. I cold started & immediately hit the "M1" button which I have dialed into the most aggressive settings. After shifting the car into gear and slightly pressing the gas petal the car hesitated and then a very loud clunk before moving forward. This has so far happened twice on cold start. No idea what's causing this. Anyone else experience this?
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08-04-2016, 07:56 PM	#2
RowanBuds Colonel 1707 Rep 2,053 Posts Drives: 3 pedal 718, G05, MkVII GTI Join Date: Dec 2008 Location: Bergen County, NJ iTrader: (0)	I get this occasionally too, but it seems to be after I've washed the car then put it away for a few days. I just assumed it had to do with it being put away while slightly damp at the rotor/pad interface. edit - I had the car at Bimmerfest East last weekend and my ride home was filled with heavy downpours. When I got home the car went right into the garage soaking wet and was parked for 2.5 days until I could wash it. When I then put it in gear and tapped the gas to back out of the garage I heard that clunk the loudest/harshest I have ever heard it. To my brain that reinforced the assumption of parked with damp braking system. __________________ Moved to the darkside: '23 718 GT4; 11-10-2022. Le Mans Blue F80 - Munich 5-22-2015 / US 7-7-2015 / SOLD 9-17-2022 ED Recap Arctic Grey G05 - Spartanburg 8-29-2019 X5 PCD Recap Last edited by RowanBuds; 08-04-2016 at 08:37 PM..
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08-04-2016, 08:11 PM	#3
///M-er-gized Captain 687 Rep 663 Posts Drives: 2019 540i Join Date: Mar 2015 Location: Florida iTrader: (0)	The only thing I notice is that when I first got my car, and I pushed the start button, the car started immediately. Now when I push the start button, it takes a couple seconds. I was going to start a thread for this, but decided not to. I still might... A couple seconds might not sound bad, but it's definitely noticeable. Also, I had an F30 335 before this, and that always started immediately too, and I never experienced any sort of delay like this. I don't want to highjack your thread, but while we're on the subject of cold starts, I thought this might be a good opportunity to throw this out there, and maybe get some feedback... __________________ 2019 540i \| Black Sapphire \| Black Dakota Leather with Blue Stitching \| M Sport Package \| Executive Tier \| Driver Assistance \| Parking Assistance \| HK \| M Sport Brakes \| Leather Dashboard 2016 M3 \| YMB \| Black Extended Merino \| CF Roof \| CF Trim \| DCT \| Adaptive \| Executive
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08-05-2016, 06:26 AM	#5
RickFLM4 Brigadier General 10981 Rep 4,821 Posts Drives: M4 Join Date: Jul 2015 Location: PB County, FL iTrader: (0)	I also live in South Florida and my car often sits for days. I don't recall hearing any loud clunks over the past year+. __________________ Current: 2018 SO/SS F83 ZCP Gone: 2015 SO/SO F82
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08-05-2016, 06:56 AM	#6
TooFan328i First Lieutenant 224 Rep 382 Posts Drives: 2016 YMB M3 Join Date: Jun 2015 Location: CNJ iTrader: (1)	Do you use that handbrake? Did the noise come from the rear end?
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08-05-2016, 07:40 AM	#8
CaryTheLabelGuy Colonel 2634 Rep 2,809 Posts Drives: 2016 M4 ZCP Join Date: Mar 2015 Location: Jacksonville, FL iTrader: (0)	Had it recently rained? If so, the brakes will rust really easily and the pads will stick to the rotors. When you start to move, the brakes will sometimes make a loud "clunk" as the pads release the rotors. Totally normal.
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