Most commonly a vibration while driving is from a broken belt in one of the tires, but if it's vibrating while sitting still, it's usually from loose motor mounts and/ or a higher than necessary rpm
inside the gas tank
700 RPM
It should be behind the glove box in an access panel.
Maybe on the passenger side near the firewall
Check firing order
On the transmission under the shifter cable bracket
1-6-5-4-3-2
Old age Frozen or misaligned pulley
could be blown fuse or short in wiring
Where is the thermostat located on a 1987 Buick LeSabre?
The relay panel on a 1987 Buick Park Avenue is typically located under the dashboard on the driver's side. It can be found behind a trim panel or cover, which may require removal for access. Additionally, there may be a fuse box nearby, as both components are often situated in the same area for convenience. Always refer to the vehicle's service manual for specific details and diagrams.
On Second Avenue was created in 1987.