Very quick and nice job is to replace the seal under injector. I have to say 1.5dci engine is well designed . Easy access to glow plugs, injectors, oil filter, and so on.
Spray I used for this test is cheapest Tesco brand window cleaner
On the videos you can see "something" is going on.
As it is very simple engine getting to the injector seal is very straightforward
As you can see the washer on the picture is loose. It should be tight sitting on the jet
And it is clearly out of shape
New seal costs only £2.50. Time to get it fixed would be around 45min.