replace plentum

there is a parts place sells a plentum to replace on the buick 3800 will i need any special tool to replace the plentum on my 98 buick

I assume you mean "intake plenum" instead of plentum. I assume yours leaked?

As far as tools go, you shouldn't need anything other than your basic hand-tools--ratchets, sockets, wrenches, pliers, screwdrivers, etc. You will need a new gasket kit, though. The new plenum may come with a gasket kit, if not they run around $30 and you should be able to get it at Autozone or similar.

I bought a plenum at autozone, it came with gaskets, the only thing that I bought extra was the o-rings for the injectors. It did not come with them, and I probably did not need to, but I replaced them anyway.

Other than the wiggling the plenum under the wiring harness, it wasn't much trouble to replace.

That was at 115000mi. What happend to me is that i had gunned the engine on the interstate to pass another car, and the engine lost power all of a sudden. I noticed a steam cloud behind me, and as it hobbled to the next exit (2mi). I checked the radiator, and I could not see any fluid inside. I drove around the corner to a gas station and bought a jug of prestone and filled her up. I was only 6mi from home, but I only made it about a mile before the engine hydrolocked (cylinders filled with coolant).

I got it towed home, pulled the plugs and cranked the engine (blew the water out). Squirted oil into the cylinders and cranked it a little more. Then replaced the plenum, oil change(oil looked like a strawberry milkshake), and fired it up. So much smoke came out, the neighbors thought my house was on fire and called the fire dept. after about 5 minutes, the smoke cleared and the fire dept arrived to find that all is ok. Its been running fine since. I have 140000 on it now.

good luck.