have you ever turned on your car and the spedometer went all the way to the 120 mph mark??
why does it do that...is it because i wired a bunch of lights(neons/strobes) from the fuse box?



p.s. i drove a '00 z-28 today, wow can't wait till i have 7 grand for a trade in!

 

no, I doubt it's anything YOU did. My 98 does that every once in awhile too. As a matter of fact it did it this morning. And I don't have any "extra" electronics on my car - besides my amp, head unit and sub that were done professionally over 2 years ago. Don't know why the speedometer does that. Curious myself.

 

it's just making sure when you decide to go 120 that it will indeed get there

 

any ideas?

 

hmm when I rented a 00 grand am GT and start the car it would always do that,I guess it checks if the speedometer is working

 

i know whats wrong with it....when i blew out all my electrical becuase of my system the car would do that... when i was driving if the system drained too much power the speedo would go to 120 like nothing....wish i had video...made it look like car was fast as hell. anyway u guys notice u both are draining your electrical. check your battery to see if it needs replacement or test the output on the alternator. apparently i boiled my battery and it needed to be replaced. go figure and it was the biggest car battery they make.

 

I would have to disagree with you. My battery is a brand new Interstate battery and the alternator has been checked and it's fine. Plus, you mentioned that your speedometer jumped while driving. That's not what's happening here. The speedo jumps sometimes at startup - not while on the move. Thanks anyway.

 

yeah, mine did the same thing when I first bought it. Except the tach would go over as well. Hasn't done it to me in over a year now though. Its just one of those things...Just wants to see if you're paying attention to it, i guess

 

I had problems like that once, the transmission was running like crap and the speedo and tach were jumping all ove the place.

The mechanics thought I had water in the computer but I just replaced the speed sensor on the transmission and all was better.

 

What year f-body was that? and what probs were you having with the tranny? i've got an odd issue with no solution from mechanics here - after tranny warms up (30 mins highway driving) the tach jumps every so often and the engine revs while i'm cruising steady about 65. Related? I dunno...

 

it sounds like you transmission is slipping. May be time for a rebuild?!?