I changed out my o2 sensor last night and had the car running in the garage with hood up, it seemed to run a bit smoother not real smooth, it seemed to shake a little and it sounds very faintly like marbles in the engine, or maybe a bad pulley or bearing? I know it meeds a new exhaust gasket becuase it is leaking at the "Y" pipe, but I know the sound I am hearing is not all that alone. Any ideas?

Well, a good way to check for pulleys is to take the belt off the pulleys with the engine off and try free wheeling each one, then carefully turning each while listening for bearing noise and feeling how they turn.

As you may have seen, it is not uncommon for idler pulleys to fail as the years get on, but you need to do somne investigating to isolate the cause.

Also, have you tried accelerating to see if the sound changes? A harmonic balancer will typically smooth out as the rpms pick up.

Eliminate the pulleys as a cause first.

I just did the HB, and now i can hear new noises, see my HB was so bad when I got the car that it clanged and banged and you couldn't hear anything. Now it ALLOT quieter and I have new symtoms, I am affraid that it may be a water pump? I don't know tho, I hope not.

Lol. Well, unfortunately you are experiencing what industrial engineers call "High Water Syndrome". When there is a lot wrong with something, whether it be a factory, a process, a system, or a car, The largest, most noticeable problems will mask any smaller, less noticeable problems.

That means that you fix the big things, then you keep going until you've resolved all the issues. If you stop before completely fixing the system/car, you get less than optimal results.

Anyway, all that drivel aside, you should now check out your pulleys first. Eliminate them as a possible cause before going to larger more expensive items like water pumps, A/C compressors, etc.

BTW, is there some other symptom that makes you suspect your water pump?

The only other thing I can think of is that there is not coolant in the overflow. I don't know if that matters. Other than that I am shooting from the hip, I know I have a less than smooth idle and don't know if its a vaccum leak or not. This car came to me with a list longer than I would care to type of problems, but it was 250 bucks from my little brother and I am making it my passion to learn all there is to know about the series 1 3800, and from the looks of this car so far, by the time I am done, I will know all........

Whoa! Slow down there cowboy! Let'* try to focus one one item in this thread at a time. Let'* eliminate the possibility of the pulleys and go from there.

but.....

BTW, while you're in there checking out the pulleys, after you're done, follow all you vacuum lines for cracks and splits and especially check the rubber connector fittings. At the age of your car it might even be a good idea just to plan to replace them all (at least the rubber connectors). Don't forget to follow the ones under your airbox to the evap. cannister also.

If you take actual solid steps to eliminate the simplest, cheapest, and most common issues for an older vehicle, you will be able to focus on the larger problems. Or, if you're lucky, you won't have all the larger problems.

Thanks lash, I just wish some people as mechanically enclined as yourself were closer so I could desifer what the F is wrong with this thing........