The garage jet-washed the DPF, which seemed to work fine, but they couldn't find the oil leak, so now it's on my drive to be looked at...
The turbo doesn't kick in, and it lacks power in general, but it does run.
There's a small amount of oil on the top of the engine (circled in red), could it just be a gasket?
Not really sure what I should be checking first - so any advice would be great!