My Mk2 Focus  1.6 TDI  mileage 28555 is  10 years old and the garage says it needs a new timing belt  should i change it  also does  it need a new water pump

10yrs or 125k miles whatever comes first. No one will say don’t bother as you won’t thank them if it breaks. They do break but I don’t know how much degradation occurs from age as opposed to mileage. Many will say replace water pump whilst it is all apart or a load of duplicated work might need doing later on. If you use a poor quality water pump it might fail earlier than the original might have done. At least this engine is easier to replace belt on than some others and hence cheaper maybe

It doesn't matter how many times the engine rotates over the 10yr period, it's still under the same tension.

Get it changed

47 minutes ago, DaveT70 said:

It doesn't matter how many times the engine rotates over the 10yr period, it's still under the same tension

I'm not sure it's about tension. Rubber degrades over time anyway, the cambelt is at least protected from water, grit and UV so should last a lot longer than the aux belt but even so it won't last forever.  Plus, of course, starting the engine puts a huge, sudden force through the belt.  A low mileage car has often done more starts than a motorway muncher in the same timescale!

Also worth noting the original coolant is only designed to last 10 years, so yes change the waterpump and coolant at the same time.  And the aux belt.  And don't be surprised if the aux tensioner needs replacement as well.

4 hours ago, TomsFocus said:

I'm not sure it's about tension. Rubber degrades over time anyway, the cambelt is at least protected from water, grit and UV so should last a lot longer than the aux belt but even so it won't last forever.  Plus, of course, starting the engine puts a huge, sudden force through the belt.  A low mileage car has often done more starts than a motorway muncher in the same timescale!

Also worth noting the original coolant is only designed to last 10 years, so yes change the waterpump and coolant at the same time.  And the aux belt.  And don't be surprised if the aux tensioner needs replacement as well.

It's tension, that's why it's recommended to change by both mileage or age. If it was rotations, they would just recommend mileage