Depends on the type of engine, but in 3800 type, remove the plastic hood (the one that bears the number: 3800) and the thermostat housing should be on the right side. Follow the upper radiator hose, it is connected to it. On the thermostat housing, you will also find the air bleed valve of the engine.
were can i locate and replace a starter for a 1998 buick regal?
Possibly... Under the air filter
I'm assuming its like other buick regal models, around the passenger side windshield wiper.
How do you take off a radiator for a 98 Buick Regal
Look at the rear of engine right side
its on the front fuse box... its marked.
How do you remove 1998 Buick regal ls sun visor
Under the vehicle just in front of the left rear tire.
If you get the PCM, engine wiring harness, and intake manifold from the Regal also..