Ok so Monday, I got on the highway and my speedo as I crested 60mph started bouncing erratically. I clicked over on my center dash display to see if the digital speed was doing it as well and sure enough... bouncing from 50-80mph.

Back her down below 60mph and she seemed fine

Yesterday, Tuesday, it was fine in the morning, then anything over 50mph at lunch, then on the way home it only bounced a little bit 70-75mph when I was in that range.

I didn't drive it today...

Have an appt for next week.

Common?

TSB s?

 

Bad cluster? Bad vehicle speed sensor? Maybe an issue in the ECM causing the VSS signal to be corrupted, I'd be curious enough to scoot by someplace and have the codes pulled if it has even set any.

 

try it with cruise control on. if the cruise works with no problems then the problem would be an output and not an input. my be cluster time.

 

But it can't be the cluster if the digital version in the center of the dash is doing it as well. Has to be the speed sensor or something in the ecm. Right?

 

I'm thinking the VSS or ECM because the center display is also acting up, I'm curious as to what they do find.

 

my service writter thinks its the VSS... either breaking or possible ice issue.

But of course I ask here before I leave it all in the hands of the dealer. I like to have all my homework done.

 

Not sure about gm but on dodge and jeep the cluster is it's own module that uses info from the ecm then make the gauges move including the center display. thats why I wanted to see if the cruise would drop out or go up and down with the speedo, if it does then I would look at a speed sensor or ecm

 

Possible VSS wire/sensor damage during engine install?

 

Exactly.... it's not at just one or the other.

I said the same thing. Or who knows.

My concern is that... if it wasn't properly sealed and water/ice got in it... does that mean there could be water in the trans as well.

 

My friends ugly ass '94 Taurus used to to that when she hit 60mph... Car wasn't worth getting it fixed though,