Vehicle is a 92 with nearly 160k
This morning the speedometer started out fluctuating and reading high. When I was going about 50mph, based on a 55mph speed limit and the speed of passing traffic, the speedo was showing about 65mph. It was bouncing about that reading up and down by a couple of mph. When the SUV is stopped at a light the needle come back to zero.
The tach showed steady rpm and the cruise control held the speed it was set for. The odometer seemed to be ok, but I don't have a measured area to check it against.
I have the service manual and it shows lots of things to check A lot of those checks have to do with the cable, but I have trouble visualizing why a bad cable would cause a high reading.
The temperature here is cold for Florida, but still it was around 35. After driving about 6 miles and stopping for about 30 minutes, the return trip had the speedo act pretty much normal at 55mph with just the slightest fluctuation. This again this was with cruise on.
What are the most likely faults that would cause this: a bad head, a cable problem (lube maybe) or a speed sensor?
Charlie