Time to change the CPU Fan?

I have a dell inspiron 1520 with the following specs:
Intel Core 2 Duo T7250 2.0GHz
2GB RAM
NVidia GeForce 8600GT

I have been monitoring the temperatures for my system and find that for low to moderate loads such as browsing and word processing the temperature are as follows:
Core 0 & 1: Approx 59 - 65C
Graphics Card: Approx 61C
Motherboard: 67C

Note: The heat sink is designed such that the heat from the motherboard must pass through the CPU before the cooling fans.

During heavy gaming sessions you can hear the fan work hard and more often than not the computer screen blacks out. I attribute that to overheating.

On a regular basis I can hear the fan working, although when I first bought the system I remember the fan was near silent. Fan and heat sink are both clean, not too much dust. Thermal paste is applied.

I would like to know if any of you have experienced fan efficency decreasing over time and if I should buy a new fan. It's not something that can be directly measured but it is reflected in the temperatures.

Personally I'm not a fan of notebook coolers either. I've always seen them as a bandaid solution to a serious problem.

Thoughts?

Hi and welcome to Tom's forum.

When was the last time that you cleaned the rig?. The fan as all components lost efficiency with the time and in some point need be replacement.

A side question: Do you sell that GPU?