Engine oil leaks on 2.5 n/a diesel

Hi,

my old 110 ex MOD just failed the MOT due to the engine being excessively oily and dirty and too many leaks... now this has been going on for years, one of those jobs that I will "get round to next week" etc... for about the last four years. I thought it was probably the gasket around the fuel lift pump, but having had the engine thoroughly cleaned and de-greased I can see that oil (and probably diesel) is in fact leaking from all 4 injectors and running down the side of the engine and also that oil is leaking from the top rocker cover nuts and leaking all down the other side of the engine. Also some coming from the oil filler cap..

now before I start tightening everything up I read that this might be signs of too much pressure in the top part of the engine (cracked pistons, worn piston rings etc...)

1. Is there any self test I can do to see if it is excessive pressure?
2. on old 2.5 engines can you get a kit for new washers for the injectors?
3. If I do get new seals and tighten everything up to stop the leaks, would the excess pressure damage the engine in any other way?

Thanks,
John

@JohnPort , it sounds like your 2.5na really needs a proper, proper service before you start worrying about pistons. I'd complete the following and get re-MOT'd first

1. thoroughly clean engine and engine bay - use a steam cleaner, then a thorough clean using Gunk and work in with a brush, leave to soak in and then steam off - a clean engine and engine bay enables you to see early on any engine leaks and is a much better place to with.
2. now with clean engine, replace injector seals and lift pump gasket
3. replace fuel and air filters
4. replace engine breather and check air breather pipes are spotlessly clean throughout - people always forget this and a blocked breather system will cause all sorts of engine leaks over time.
5. replace oil and oil filter - Q? when was the last time you ran diesel cleaner through the engine for a few weeks? Old diesel engines need to be cleaned to clear crud and keep oil galleries clear, especially upper head/rocker gear
6. replace rocker cover gasket fitting new gasket with a smear of Hylomer Blue

All gasket/seal/injector part #'s and suppliers can be found here

https://www.lrworkshop.com/diagrams/land-rover-defender-engine/2.5-na-naturally-aspirated

Thanks for that - yes, I have had the engine thoroughly cleaned and it has now passed the MOT. The reason I was asking about the pressure was that with the engine cleaned you can clearly see multiple oil leaks, all from the top end of the engine. I think i read somewhere that removing the dipstick and covering the hole with your thumb (while the engine is running) can give you some idea if pressure is building within parts of he engine that it shouldn't. The engine runs very cleanly (not much exhaust smoke) but I will get some injector\engine cleaner for it as it has been a few years since any was run through...

cheers for the parts link.

PS - the injector seal washers on these old 2.5 na engines are the steel washers, not the copper ones, right?