Noisy wiper motor!

After a few hours of having the wipers going today I've noticed the whine the motor is making is louder and more obvious from before.
Is this a sign of it being 'on-the-way-out?' or is it just something it does when it gets hot?
It's on a TD5 defender btw.

i hv the problem on the wiper motors on my 110...even after spraying the motor with wd40...still get that 'wheeer wheeeer' noise....any ideas anyone...?

Take it apart and use some lithium grease not WD40.
WD40 is not a lubricant as such. It is meant as a water dispersant. It lubricates for a short while only.
If you dont want to strip everything down then try using 3 in 1 which is a lubricating oil.
It will last longer than WD40 but no where near as long as grease.