Hi, My Focus on 40k miles (70 plate) failed its MOT on emissions last week and also required 4 litres of oil that had somehow disappeared (no leaks) since it was changed back in August (4 months), my bad for not checking frequently. The garage topped it up and I understand did a forced regen/test drive to get it through the MOT on emissions. The dash message comes up on every drive (short runs of 4 to 5 miles) to say the Exhaust filter is clogged, drive to clean, followed by Exhaust Filer Cleaning and after approx 5 miles says exhaust drive completed. Sometimes it just displays exhaust filter cleaning with the follow up completed (i.e. no Exhaust Filter clogged). The car runs fine, no smoke that I'm aware of. I've checked oil level today having driven about 50 miles since it was topped up last week and again its lost some, dipstick down by about quarter of inch ! Any ideas why, is it the DPF or are the two issues, oil loss, constant Exhaust Filter cleaning, two separate issues ? I'm removing the under cover today to check for leaks.

Poor maintenance by the sounds of it, you probably have bore wear.

The DPF is probably catching all the smoke which is why you aren't seeing any and why it's always clogged

I'm surprised it needed 4 litres without seizing up or no low oil pressure warning

Thorough investigation required, including tear down I would say

Ouch, appreciate that could be the issue, but comes as a shock when its only on 40k miles ! I agree, as to the lack of any oil warning, although the 4l the garage mentioned did put it at the very top of the dipstick, possibly over.

Edited December 9, 20241 yr by Dave1960
added info

Double checked for leaks and there are none. Also had a look into the Turbo air inlet side and a small puddle of oil in the pipe inlet to the turbo, about the size of the penny ?? I guess I'm trying to determine if its anything other than bore wear and hence less expensive fix ? 

Some oil in the turbo inlet is normal.  It comes through the crank breather as vapour and condenses over time.  May be more than usual in there if the garage did overfill it.

I'm also very sceptical about losing 4 litres of oil in 4 months without any signs though.  I know it's more hassle but I would recommend getting the DPF off to look into the exhaust side of the turbo next.

Many thanks. If and when I can get round to looking in the exhaust side I presume if there's oil in there it could suggest the turbo oil seals ? Is there usually any oil in that side at all ?

2 minutes ago, Dave1960 said:

Many thanks. If and when I can get round to looking in the exhaust side I presume if there's oil in there it could suggest the turbo oil seals ? Is there usually any oil in that side at all ?

Correct.  There shouldn't be any oil in that side at all.  Just dry soot.  If oil is in there then it usually means turbo oil seal.