Hey guys, I have never seen anything like this nor can I make sense of it.

When I am in nuetral not moving (5 spd) with the parking brake on and I rev the engine to about 3000rpm and give it a tap to 4000rpm my speedometer jumps!?

after a 10 minute drive and stop sometimes it doesn't happen.

The car is running great as usual nothing different,no issues, no check engine lights etc.. the speedometer functions normally while driving as well.

Has anyone ever seen this? could it be a sign of trouble?

here are the video clips...


http://www.youtube.com/watch?v=W7WYMxIhAU0

http://www.youtube.com/watch?v=iUK96ymwT1c

 

What about when your parking brake is not on? Does it still do it?

 

yea it still does it...

 

wierd..

 

mine does it.

 

really!? wtf lol

 

lol
I love to show off my O/R exhaust, that's when I noticed. Not sure if it was like that before the tune. Haven't tried flashing stock yet either. I'm not worried about it though, because like you said everything works fine.

 

hmm...my mark VII dash light dimmer changes the tach and moves the speedometer...ford must have some very unusual instrument cluster wiring/grounding/programming ideas

 

what mods do u have?

 

in sig... just a C&L racer with a few different tunes i try out.

 

Several of us have had our clusters go bad and some of the gauges will intermittently show incorrect readings when they do , on mine the speedometer will sometimes show 40 MPH when I'm setting still. Not exactly the same thing you're experiencing , but it might be related ...

 

thanks for the info it could be a sign of things to come... i am going to bring it up at the next oil change. cluster going bad? but still everything works fine lol

 

Mine does that too. If the park brake is on it beeps a warning when I revv it that the brake is on, and the speedo jumps all over. I don't think it does it with the brake off.

It's just a feature!

 

Your speedy jumps too? well thats 6 people so far.. some people still say their car doesnt do this. and it also does it with the parking break off if i just sit there and rev.

 

mine does it sometimes too when I have the e-brake on and I rev it, mines an 05

 

I tried in the grocery store parking lot, but didn't get past a few 2-3k rev's, because I was making too much of a racket... will try tomorrow morning on an empty road.

 

I have an auto and I notice after putting it back in to "P", the speedo jumps just like that occasionally.

 

With your mods, you might be pegging your MAF a bit till the car warms up. Do you have a tuner you can do some data-logging with?

 

HMm never thought of that but the car runs fun all i have is a C&L racer really. and yea my SCT x3 data logs. i don't think its an issue i was thinking maybe i got an auto tranny tune? lol but that sounds crazy but so far 8 people have said this happens.

 

Could also check your vacuum tubes, and make sure your TB is clean.