Inaccurate Speedometer?

jumpthewire · 08-19-2010, 04:13 PM

hey guys,

i've been noticing my speedometer seems inaccurate.
The MPH seems "sluggish" on both acceleration and decelerating.

I also noticed my RPMS is not at 0 when the car is started and idle in Park.

I did recently removed my gauge cluster to clean the lenses and am wondering if i possibly "moved" the needle?

note: when the car is off- both the meters are at 0

thanks
shawn

nesrevival · 08-19-2010, 04:31 PM

Every car's rpm is at dat point.....when u start the car rpm goes little above 1000rpm
And it goes down to about 7000-8000

jumpthewire · 08-19-2010, 04:38 PM

ok. i kinda figured the RPM was ok. maybe im just crazy. just seems the "responsiveness" of the MPH is sluggish.

dekaliber · 08-19-2010, 05:36 PM

Your car needs to idle at a certain RPM > 0 -- otherwise your engine would stall.

As far as the sluggish MPH response, it looks like you have an automatic transmission, which operates through a torque converter vs the the direct gear-to-gear engagement you'd find in a manual. It's a fluid coupling vs. a mechanical one, which is why your car can be in gear (drive) while you're stepping on the brakes, and still not go anywhere. For that same reason, there will be a slight lag between the RPMs and your speed.

jumpthewire · 08-19-2010, 05:54 PM

ahh...makes sense...thank you for explaining!

08-19-2010, 04:13 PM	#1
jumpthewire First Lieutenant 26 Rep 316 Posts Drives: 2007 silver/grey Z4 3.0si Join Date: May 2010 Location: Los Angeles iTrader: (1)	Inaccurate Speedometer? hey guys, i've been noticing my speedometer seems inaccurate. The MPH seems "sluggish" on both acceleration and decelerating. I also noticed my RPMS is not at 0 when the car is started and idle in Park. I did recently removed my gauge cluster to clean the lenses and am wondering if i possibly "moved" the needle? note: when the car is off- both the meters are at 0 thanks shawn Attached Images
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08-19-2010, 04:31 PM	#2
nesrevival First Lieutenant 28 Rep 392 Posts Drives: Z4MC 07' Join Date: Oct 2009 Location: CA iTrader: (2)	Every car's rpm is at dat point.....when u start the car rpm goes little above 1000rpm And it goes down to about 7000-8000
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08-19-2010, 04:38 PM	#3
jumpthewire First Lieutenant 26 Rep 316 Posts Drives: 2007 silver/grey Z4 3.0si Join Date: May 2010 Location: Los Angeles iTrader: (1)	ok. i kinda figured the RPM was ok. maybe im just crazy. just seems the "responsiveness" of the MPH is sluggish.
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08-19-2010, 05:36 PM	#4
dekaliber Major 75 Rep 1,143 Posts Drives: '07 Z4MC, '11 JCW, '18 Z06 Join Date: Mar 2008 Location: Los Angeles iTrader: (1)	Your car needs to idle at a certain RPM > 0 -- otherwise your engine would stall. As far as the sluggish MPH response, it looks like you have an automatic transmission, which operates through a torque converter vs the the direct gear-to-gear engagement you'd find in a manual. It's a fluid coupling vs. a mechanical one, which is why your car can be in gear (drive) while you're stepping on the brakes, and still not go anywhere. For that same reason, there will be a slight lag between the RPMs and your speed.
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08-19-2010, 05:54 PM	#5
jumpthewire First Lieutenant 26 Rep 316 Posts Drives: 2007 silver/grey Z4 3.0si Join Date: May 2010 Location: Los Angeles iTrader: (1)	ahh...makes sense...thank you for explaining!
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