Mitsubishi Repair: 2001 Galant... strange, mechanic check, pitch sound

Question
Thank you, I'll have a mechanic check out those things.  My car has around 80,500 miles on it ... I just paid it off a few months ago(yahoo!!) and I want to maintain it in good condition ... what should I be doing other than changing the oil every 3,000 miles?  The manual says new timing belt, water pump, and I think a CV joint(?)? -- Thanks again in advance for your help!
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The text above is a follow-up to ...

-----Question-----
I don't know what this strange sound is ... it concerns me.  Every now and then my car makes a strange low-toned pitch sound (kind of like a "whoooop" sound ..a low to high pitch at the end).  Driving speed is around 30-45, it has made the sound going straight, at a light, and in a turn.  The sound happens every few months, and then nothing.  The sound will happen a few times over a period of weeks, then it will just disappear.  Sounds like it's coming from under the hood.

Can you make any sense of this?  Thanks in advance.
-----Answer-----
Lorraine: Oh gee, that could be anything. But here are three things to check, one would be your engine belt. Make sure it is tight, sometimes when the weather is warm, cold or wet if the belt is getting old or not put on right; it would be slipping and so making a noise. The other thing would be to have your outboard CV joint checked. It might be causing the noise. Also might check your power steering fluid, it might be low. I do hope this helps with your noise and good luck!

Answer
Lorraine: I am happy for you getting your car paid off. You must be happy about that one. You know I never thought about this but that noise you were talking about might be due to the fact that your water pump is going. I did not know the miles on your car or what kind of a car it was. You should have that checked. A good tune every 30,000 miles to 24 months, it would keep the life of the car going long into the 100,000 miles mark. I guess I would have the timing belt checked, but they seems to last into the 100,000 miles but if the company thinks they should be changed then do whatever they tell you. They know their cars better than me. Yes have those CV joints checked too. One thing with the timing belt if you have it replaced now, you will not break it going down the road sometime. That can be very hard on the engine. Oh yes if the car is an auto have the fluid and filter changed once in a while too. I also try every 30,000 miles to 24 months to have the radiator back flushed and then put in new antifreeze. At that time have your mechanic check your hoses and replace them if need be. Everytime he does some work on your car, have him check your drive belt and if need be replace. Not everytime, but I mean have him check it. They last for miles but once they start to show age, then they should be replaced. You could if you like go buy yourself a repair manual for your car, you could get one at any parts store for around $20.00. Then you could read up on your car and know about things if someone started saying you needed something. You would know if they were telling your the truth or not. Sometimes people are not always honest on repair for a car. But just an idea on my part, other wise most librarys have car repair manuals and you could just read on your car there. I do hope this helps and good luck my friend!