Bought it a year ago with 70K miles and it went fine for a month then speedometer went to a hundred and then pegged while driving at normal highway speed. Cost to repair estimated at up to 1 grand because whole dash had to come out to replace unit. All other instruments incl odometer operative. Bought GPS with mph readout 100 bucks. Other than the power steering sounding like a tom cat being castrated without benefit of anesthetics when making slow speed turns (parking) I thought all was o.k. Then the motor lost all but enough power to get it to my mechanic who discovered that the rocker arm bolts were stripped on the inside (natch) rack which meant serious dissassembly, and helicoiling for new bolts. Bigger job than it sounds, about a half of a grand. My dad told me that if I ever bought a Buick I would never get a lemon, but that was in 1950. More to come: While driving car stalled out- restarted- stalled and repeated all the way to my mechanic who drove it and it was fine, then drove it again and it repeated the problem. While in his shop the heater fan came on (like it always does with the switch cut off, he rolled his eyes and said- take it to the dealer! The gas tank was at 1/4 full when all this happened and the dealer suggested that maybe the gas gauge was faulty, but we drove it 20 miles that way sputtering and then running like nothing was wrong with it. He also said that it was likely a computer problem associated with the motor. When the dealer put five gallons of gas in the problem went away so now I always fill it up when it gets between half and a quarter. Car rides well, comfortable, but I am always waiting for another shoe to drop.
You may have accidently put the speedometer into the kph mode instead of the mph mode. I think in your model, it is set with the radio, where you reset the odometers and the oil change light.
Thanks, but no the speedometer is correct about 90 % of the time. I can reset it when it goes whacky by turning the switch of and on about ten times. Each time it decreases about 10 mph as it sticks on 120 when you cut it off when it is malfunctioning. Actually this is the least of the problems and I soldved it well with the GPS! But thanks for the idea.