Hill holder
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Joined: Sep 2016
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From: WA
Hill holder
2013 911 CS2 PDK. I'm experiencing a rattling, clanking, metallic sound (that only lasts for seconds) when I pull ahead after the "hill holder" has been applied. It's intermittent at best because I rarely have to use that feature, but when I do, sometimes, it will make this sound. It only happens when the Hill holder is involved. The local dealership replaced the right parking brake motor, but that didn't fix the problem. I hope I'm not the only Porsche 911 owner that has experienced this, and that someone out there will have an answer. Thanks
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From: Minnesota
Can't say I've had this happen, but I'm on a .2 PDK, which is a different unit.
Is the rattle/clanking sound rotational in nature? If so, does it speed up with engine RPMs or vehicle speed? Or does it just sound like a loose thing bouncing around?
Is the rattle/clanking sound rotational in nature? If so, does it speed up with engine RPMs or vehicle speed? Or does it just sound like a loose thing bouncing around?
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Joined: Sep 2016
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asellus, I would say rotational in nature. When it happens I will immediately let off the gas until the noise goes away (seconds). I think it's in the parking brake system somewhere as it only happens when the hill holder is applied. My indy guy has checked both e brake shoes for loose brake shoe parts but all appears normal. Porsche replaced one brake motor and said the other one was ok. I guess I should be glad the noise only lasts seconds.
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Any chance you can try to get a recording of it? I assume it can be reproduced reliably?
If it's rotational it's going to be engine related (rpms) or wheel hub related (vehicle speed). Two things are happening when you start to go after employing a brake hold -- one, the brake releases, and two, the PDK clutch begins engaging. The speed of the rotational sound will be very different depending on if it's either of these components.
I'm not sure if the hold mechanism on the .2 is the same as the .1. When I depress my brake pedal a little harder, or if I'm on a steep incline and I have hit the brakes, the brake pressure is simply kept on all four wheels as if I'm still holding the brake pedal. The ebrake is never actuated in normal use unless I open the door with the car in gear and running, or I use the aforementioned hold mechanism for a long time (something like 5 minutes). If I don't manually disengage the ebrake, when I hit the gas to do it the car will lurch against the ebrake which is still grabbing before it releases. There are some clunking noises to be heard there, but they're only singular for each side, like breaking a brake loose when you first move a car parked outside in the rain/snow for a few days.
If it's rotational it's going to be engine related (rpms) or wheel hub related (vehicle speed). Two things are happening when you start to go after employing a brake hold -- one, the brake releases, and two, the PDK clutch begins engaging. The speed of the rotational sound will be very different depending on if it's either of these components.
I'm not sure if the hold mechanism on the .2 is the same as the .1. When I depress my brake pedal a little harder, or if I'm on a steep incline and I have hit the brakes, the brake pressure is simply kept on all four wheels as if I'm still holding the brake pedal. The ebrake is never actuated in normal use unless I open the door with the car in gear and running, or I use the aforementioned hold mechanism for a long time (something like 5 minutes). If I don't manually disengage the ebrake, when I hit the gas to do it the car will lurch against the ebrake which is still grabbing before it releases. There are some clunking noises to be heard there, but they're only singular for each side, like breaking a brake loose when you first move a car parked outside in the rain/snow for a few days.
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asellus, No chance of a recording the noise, it's so intermittent. On the .1 when you apply the hill holder a green "Hold" will appear on the dash. When you take off the light goes off. Iv'e eliminated the PDK clutch as a problem because under normal driving conditions there is no noise. Only when the hill holder is applied. This car must have been built on a Monday. I'm off right now to have my squeeky fuel tank issue looked at.
,
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Joined: Sep 2021
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From: Seattle
Similar issue
2012.5 C2S PDK. 42000 miles. Mine does it only when the car is cold and making a turn from hill hold stops.
Thers is an uphill intersection near my house and every morning when the engine/transmission is still cold, car makes metallic rattle as i turn from hill hold stop. I come off the gas momentarily and the rattle stops. I tried putting in neutral when stopped, but as long as the car is cold, moving foward from hill hold and turning, it makes the noise. I dont use that route anymore when the car is cold. Once warmed up no issues.
My warranty expired long ago. Im gonna replace transmission fluid on the next oil change and inspect parking brake / hill hold mechanism.
I kinda want to code out the hill holder if possible since my car is not a manual and dont really need that function. (I enjoy auto hold on my wife's X5 very much since it is actually convenient).
Thers is an uphill intersection near my house and every morning when the engine/transmission is still cold, car makes metallic rattle as i turn from hill hold stop. I come off the gas momentarily and the rattle stops. I tried putting in neutral when stopped, but as long as the car is cold, moving foward from hill hold and turning, it makes the noise. I dont use that route anymore when the car is cold. Once warmed up no issues.
My warranty expired long ago. Im gonna replace transmission fluid on the next oil change and inspect parking brake / hill hold mechanism.
I kinda want to code out the hill holder if possible since my car is not a manual and dont really need that function. (I enjoy auto hold on my wife's X5 very much since it is actually convenient).
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Thread Starter
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From: WA
Hi Jae, everything you describe is whats happening to me, except it's happened when the car is warmed up too. Maybe I'll try coding mine out too. BTW are you going to the Porsche show at Carillon Point Sunday?
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