My 2003 Deville (base Deville model) occasionally hesitates for a brief, part of a second. It feels like the gas pedal has been moved up some and quickly back down. Not enough for the speedo to change MPH, or the digital Tach to change, but I can feel it. It never does this while accelerating, only at constant speeds, so I ruled out the fuel filter. I replaced the throttle position sensor - didn't help. Sometimes I can drive for days/hours without it happening and some times it happens 3 or 4 times in 50 miles. Only seems to happen at highway speeds. I use Cruise control a lot, and it happens with the cruise on or off. Car has 150,000 miles, and has been doing this for at least 50,000 miles. When it does it, it often does it 3 or 4 times in a row, then is OK for a long time.
I also have a 2001 Deville DTS that has only 45,000 miles. This car does the same thing , but only about once every 500 to 1000 miles.
Both cars have Northstar V8s .. The 2003 is 275 HP, and the 2001 DTS Deville is 300 HP, but basically the same engines in both cars.
What are your thoughts? Anyone else have this problem?
Thx,
Dave