I had installed the cosmo racing intake which sits right above the positive batter terminal. I capped the terminal so its not knocking. I also just put 4 new speakers in, just replacing other aftermarket speakers. I have a cap to my amp for my 2 subs. It never had any problems until about 2 weeks after intake and a week after speaker install.
I dont think its a problem with the recent installs, but im just letting you guys know.
Well it started when i got on the highway one day and i looked down at the speedo and it said 90mph. I was going like 65mph. I stopped at a light later and it sat at 25. I unhooked the battery and let it sit to reset computer and plugged it back in. Works fine. Also, my headunit was freezin up a little and asking weird things like "choose different disc".
I went a few days and until today it hasnt done it. I got home from class and it was at like 10mph over. I left it at my house and rode around with a friend for a couple hours then got back in. It was at 0 but about 1/2 mile from my house it started messing up again. I started driving and saw it climb high. Then I would slow down and it would decrease speed or so it looks like normally. It got so bad by the time i got to the store It had gone all the way around and was pointing straight down.
I realized that each time i start my car up it knocks the speedo down 5mph. Sometimes it knocks it down when its just sitting there off over a period of time. I just started it up 3 times in a row to test it and sure enough it put it down 15mph. So right now my gauge says 65mph
WTF is what i ask
Could it be speed sensor?
Could i have shorted a circuit?
Fried a computer or something?
Blown fuse?
anything helps and i appreciate all who read this and take time to respond.
oh yea its a 2003 ecotec.
only thing i know about it is the symptoms, have no diagnostics or anything.
That's the SAME EXACT thing my speedo is doing. It's been doing that for 6+ months now. I'm scared to take it to the dealership to see what's wrong. Do you have rims on your car? I had some 17's back in the day & it never did that then I got 18's & it started malfuncitioning. That's the only thing I've been able to think of.....
yea its not the rims though, that would have no impact. Im thinking some wires tarted knocking behind the dash and i got a surge that @!#$ up my speed sensor. Ima take it to dealer to see if they will warranty it. If not, ill buy one and install myself. None of the technicians i work with know what exactly it could be, but ill keep you posted on anything i find out.
Yeah keep me informed. I've even unplugged my speedo from it's harness & put it back & I still get the same problem!! I'm stumped!!
