2000 Buick Park Avenue Not Ultra
When Hot the car will shudder with slight accleration in any gear. Motor mounts and MAF Senesor have been replaced.
It might be the transmission making the shutter or you have a misfire/misfires. Any lights lit up on the dash?
Mine did this when mice got under the Plastic housing that covers your engine and chewed through the wiring for the injectors causing crossfiring. THROW that thing away (the plastic housing) They're mouse houses in ALL weather whether you have a garage OR park your car outside. P.S. Don't have a photo, but the injector wiring in question ran along the very front top of the 3.8L engine just forward of the rocker arm cover housings.
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