I bought a 1999 Bonneville SSEi not quite a week ago. At the time I didn't know a thing about them, but I became a fan almost immediately.

Man that thing is sweet! I can't wait to put a wrench to it. I never was into performance mods ... but I never owned a bad aSSEi Bonneville before either.

My car has 119,000 miles on it. Where should I start. I want to make sure all the vital components are up to snuff before I start adding horses. I've never owned a supercharged car before. How can you tell what condition the blower is in?

Here'* a good start:

https://www.gmforum.com/t278662/

Check your boost gage. At WOT throttle you should be running 7 to 9 psi boost. If not, let us know and we will tell you how to fix it.

Thanks. I did read that thread (a few times) and I'm sure I will check back to it often. At WOT the boost easily hits 7-9 (and throws me into the seat).

I'm a little nervous because of the car'* age and millage, but it drives like a dream. Should just stop being nervous and get to the fun?

when properly maintained, the 3800 can go for a very long time...they do have a few problems that u need to watch out for, but are pretty easy to fix

Oh man, what a tease. What are those problems I need to watch out for?

well, rust is a main concern... the passenger rear wheel well has a problem of getting major rust hole issues that you'll want to keep a handle on. Also keep an eye on the engine cradle mounts. As for electrical, the ground bus terminal which is located in the driver door jam on the floor has a tendancy of getting corroded and causing strange electrical issues. thirdly, the engine has a few quirks. usually people need to replace the nose cone bearings or the coupler on their superchargers... changing your supercharger fluid can help delay this. also, the engine is known for LIMG leaks where coolant can leak on the outside of the engine, or potentially inside and it'll eat away at the bearings. Keep an eye for leaks or chocolate milk oil and address the problem quickly if u have symptoms. For all other issues, the best thing is preventive maintenance - change all fluids as needed and don't beat on your car and it could last you 200,000+ miles!

I like the way you are approaching this, maintenance then modding.

A tune up of plugs, wires, fuel filter, cleaning coil posts if needed. Oil and trans fluid servicing, Clean down the engine and ensure no leaks etc are present. TB cleaning. Tires, brakes, check over bushings, struts etc etc.

There'* the first things on of maintenance/upkeep that should be done before moving forward.