If its got that many miles on it then it should be about time to change the timing belt/water pump/ anything else in assembly that needs replaced.  Just to save yourself trouble and money is why you should replace the other accessories that run off the timing belt if they need it.

Check and make sure it was done at the 60-75k mile range. if not get it done immediately.

If your timing belt goes out on the 420a motor then you can say goodbye to that motor, Interference engine =(

I changed mine at 75k and was lucky I did because it was about to go.