Realibility of the buick 3.8 litre supercharged engine.

Are you asking if the 3.8 is reliable?

I am asking if the superchargers are reliable, the car has 120,000kms 80,000 miles on it and before I buy it I would like to know if there are any issue with the superchargers Thanks

If they are maintained they can go 200,000 plus. The oil needs to be changed regularly in the super charger. Ask the guy how often he changed the oil in it. Also check to make sure he didn't put a smaller pulley on it to get more HP. Before you buy get the engine warmed up and remove the oil cap. Put the back of your hand over the opening and see if there is any blowby blow-by. You should get almost no air movement. If you really want to get a good handle on the condition of the engine. Hook up a vacuum gauge to manifold vacuum and see what you get. You should get 20 inches or better. The needle should be steady and should drop when accelerating then jump up when you release the throttle. 3.8 is a good sound engine if it is maintained. At 80,000 miles that engine should be in great shape.