My newly purchased Focus Diesel mk4 is due a 4th (22k miles) major service and the garage says that the fuel filter needs replacing, at a cost of £170. There’s no issues with the fuel system.

Tried searching the web and this forum, but I don’t find too many hits to backup this replacement. Is it normal to replace the fuel filter?

Yes, it's normal to replace a diesel filter every 4 years.  Used to be every 3 years before the 2-yearly servicing came in.

Means the service costs roughly the same on petrol and diesel because they change the diesel filter on the same years as they change spark plugs on a petrol.

You don't have to have the fuel filter changed if you don't want though.  It's out of warranty now anyway.

Welcome!

Depends on the size of the filter, if the massive metal cartridge it may, just may be able to go a bit longer (if you're feeling a lucky punk!)

For our element, it is dirty all round at 3 years so I change at 2 because, we had a bad batch of filters which clogged and caused limp mode whilst overtaking a lorry on a hill - we don't want to repeat that!

However ours is about £11.

What is the cost of your filter and is that dealer price or independent and can you do it yourself?

The filtration in modern Diesel Filters is so fine that I wouldn't leave it more than 4 years between changes because as @Shearers said they can clog up.

3 hours ago, Shearers said:

Welcome!

Depends on the size of the filter, if the massive metal cartridge it may, just may be able to go a bit longer (if you're feeling a lucky punk!)

For our element, it is dirty all round at 3 years so I change at 2 because, we had a bad batch of filters which clogged and caused limp mode whilst overtaking a lorry on a hill - we don't want to repeat that!

However ours is about £11.

What is the cost of your filter and is that dealer price or independent and can you do it yourself?

The MK4 focus diesel filter just is expensive unfortunately (god knows why) shame ford didn't keep the same filter housing system it had on the mk3

14 minutes ago, Neb_engineer said:

The MK4 focus diesel filter just is expensive unfortunately

Genuine filter can be bought for £71 to £85 direct from Ford.

The price of £170 seems high, even taking in to account the fitting.

I think there are two different filters used on the Mk4 EcoBlues?  Can't remember whether it was an age thing or an engine size thing.

8 minutes ago, TomsFocus said:

I think there are two different filters used on the Mk4 EcoBlues? 

Seems dependant on the engine size.

1.5 or 2.0 diesel