Well, if the speed was accurate, I would be very happy.
It was the speedometer behaving funny. I have 98 CSVT. The speedometer and odometer have been very accurate for the past 8 years (tested against my Garmin 2720 GPS). This afternoon while driving in D.C.'s rush hour, I drove over a man-hole bump and then immediately observed the speedometer needle shaking back and forth. When I had a full stop, the speedo stayed at 0 MPH. Then when I slowly started, it moved very fast to like 40 MPH and then jumped between 40 and 80 MPH. When I finally drove on 495 at regular speed (about 60 MPH), the speedo jumped between 80MPH and 120 MPH. The techometer was always steady. The AC was on, the radio was on, no strange wiper action.
I did a search and found most likely it was due to a VSS failure. Some also mentioned it could be battery problem. The battery was recently replaced 1000 miles ago. I haven't tested the battery and alternator. I should pick up a multimeter for that. But from the description, it seems to be either a VSS or the speedo itself. Since VSS is cheaper, I will try to start from this.
I found in Tony2005's post (from unisys12 I think), the VSS part is F-F5RZ-9E371-BC. However, in the write up the transmission was CD4E, not MTX75. Will the part be the same or different? Also, currently I have the E0s with 205/55/16 (original size for 98) but I have a set of E1s with brand new 215/50/16 BFG Traction V in my garage. I know that will throw off my speedo reading by about 6%. In order to fix that, can I find different VSS for different model year, or do I need to use a speedometer for 99-00?
I remember not long ago there was a discussion on the instrument cluster. It seems 98 CSVT and 99/00 CSVT's clusters are not interchangeable. Is it true? Can I just use the speedometer from a 99/00? I found it is almost impossible to find a 98 CSVT speedometer with miles less than 80K.
I really appreciate any help. Thanks!
