Mitsubishi Repair: Overheating Problem, temperature gauge, oil pumps

Question
I have a 98 Eclipse ith 100k miles.  About 5 years ago, my radiator was damaged by a foreign object and was replaced.  The dealership had said that the engine cover was warped and there as a whirring sound and knocking sound from the lower engine area.  It also makes a whistling noise when I start in the morning when it is cold.  Some tell me that it may be my water pump bearings.   I have been driving like that for the last 5 yrs ith no problem.  No, it appears to be overheating on the temperature gauge rises quick in the hot weather here.  I notice that my radiator is leaking a little bit also but I cannot see a noticeable leak (it may leak 1 cup in 1 week).  However, it only takes about 5 minutes for the temp gauage to go up really fast.  Any ideas or suggestions?

Answer
Larry,
If, 5 years ago when your radiator was damaged, your engine overheated, that may have warped your engine head.  But I would get a second opinion on the warped head (cover).  The noise you're hearing may be your water pump or your oil pump.  Oil pumps on Eclipses are known to be noise when your engine is cold.  This is typically because engine oil can be harder to circulate when it's cold if you have a high weighted oil.  The motor oil weight, I believe, that is recommened for your car is 10W-30.  If you live in a very warm area (like the south west or Florida) and the temperature never gets below 30F, then you can use as high a weight as 20W-50.  But if your area experience cold winters, stick with 10W-30 or even 5W-30.  Also, make sure you have enough oil in your engine.   

As long as your temperature gauge stays out of the red area of the gauge and settles around the middle, that's fine.  Your fast heating may be due to a stuck thermostat, which is inexpensive and relatively easy to replace.  You should also have your coolent system flushed every 2-3 years.  

If you've never had your timing belt changed, you may want to consider doing that.  Typically during a timing belt change, they will also replace your water pump because you need to remove the timing belts to gain access to the pump.  You may clear up this noise if you get these regular maintenance items taken care of.  Timing belts should be changed every 45k-60k miles, though a water pump is typically only replaced during your first timing belt change.
Good luck!