water pump.....again

so 12 months after I had the water pump changed on my 2001 td4, the water pump as failed yet again.

This time, its turned the week old coolant black.

any idea what keeps killing water pumps?

Looked at the trust haynes manual.

When i looked under the car, i managed to push the drive belt off with one finger, it was very loose.

However, there is no way to change the tension as the tensioner should deal with that, even if the water pump is busted.

That implies that the tensioner is at fault. Will have another look in the morning.

The heater matrix was changed last week, hence the new coolant, so the grey in the coolant could be just crap from the new matrix.

So we have a plan going forward, at least for tomorrow.

Just been and looked, seems that the water pump bearings are warn to point that the pulley goes far enough out of alignment to cause the belt to jump off.

I suppose that why they call then ****part.