Mystery oil leak

There's oil all over the back of my TD5 Defender's engine, all over the various hoses and pipes, the engine under tray is soaked with oil and it's dripping on to the ground.

I thought l'd found the leak as the rubber bung at the front of the engine was loose, and oil was running down the side of the cylinder head to the back.

But the leak is still there. l've looked but can't see where the oil is coming from.

What's the most likely cause of the leak? l've changed the engine cover gasket when l did the injector harness, but l didn't use any silicone on it. Should l have sealed it with silicone?

Wash it off as best as you can, dust the universe with talc, run the engine, trace the tracks of oil through the talc ...

Brake cleaner is excellent for the clean up.

Check the tightness of the spin on oil filter.

l will get some engine degreaser, and talcum powder, and have a look at the weekend.
Will remove the front undertray as well

With my TD5 it can lose oil from the back of the rocker cover, especially where the semi-circular bit is on the rubber gasket. They also lose fuel from the fuel pressure regulator - from the regulator-y bit, plus the joint between the regulator and engine as well as the various compression nuts holding the pipes on. All of which anoints the back of the engine, the crank position sensor and the starter motor. It even gets inside the bellhousing and makes you think you've got a leak from the seal on the back of the crankshaft.

lightning said:

l will get some engine degreaser, and talcum powder, and have a look at the weekend.
Will remove the front undertray as well

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It's pretty astonishing that you've still got the undertray too. The padding in that can soak up a gallon or two of oil which also moistens the hundredweight or so of road dirt that accumulates in there. So it can ooze out for ages, even if you stop the original source of the leak.

Brown said:

It's pretty astonishing that you've still got the undertray too. The padding in that can soak up a gallon or two of oil which also moistens the hundredweight or so of road dirt that accumulates in there. So it can ooze out for ages, even if you stop the original source of the leak.

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I've got mine, but it's in the shed. It's been in there for about ten years or more

Al2O3 said:

I've got mine, but it's in the shed. It's been in there for about ten years or more

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Best place for them in my view. It's worth hanging on to because these days if you want to sell the Land Rover it'll really impress potential buyers that you've got all the original features.

Brown said:

Best place for them in my view. It's worth hanging on to because these days if you want to sell the Land Rover it'll really impress potential buyers that you've got all the original features.

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True, but it'll be a family heirloom I hope.

Al2O3 said:

True, but it'll be a family heirloom I hope.

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They'll be fighting over it when you've passed away.

Thank you for the replies, as soon as it stops raining l will get on to it.

When I fitted new half moon seals on my 200tdi they still leaked, had to remove, clean and seat in some RTV silicon to stop the leak.

Too much sealant is almost enough

lt looks like the leak is coming from a part at the rear of the engine, it has two pipes running to it and a sensor, these are dry, but there's some sort of round thing on the back of it that appears to have a rubber seal in the centre, and that's wet with oil, as is everything below and behind it.

That's yer fuel pressure regulator block, and the little round thing facing backwards is the mechanism I was talking about in post 6. You can get repair kits for them but when mine went I just got another fuel pressure regulator and swapped the whole unit.

OK thanks

l think l will let the garage change it, l just looked at a Youtube video and don't fancy the job, it looks a right sod.

Is a Britpart one OK or should l insist on OE?

lightning said:

OK thanks

l think l will let the garage change it, l just looked at a Youtube video and don't fancy the job, it looks a right sod.

Is a Britpart one OK or should l insist on OE?

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It's not too bad to do at home, honestly! Take the lifting eye off temporarily and you can get at most of the bolts. The pipe that goes to the front of the engine is hard to get at at its front end, because the manifold and alternator are in the way, but I left mine in place and re-used it as it didn't seem to have anything wrong with it.
The Britpart ones aren't that much cheaper than the OE, so I'd go for OE if I were you https://www.lrdirect.com/LR016318-Connector-Assy/ There's always the genuine Land Rover branded ones if you really want to bend the plastic.
There's also a little metal gauze filter just behind the regulator that might need replacing as well, because they can disintegrate and send little bits of wire mesh into the fuel gallery where they can get drawn into the injectors. It's a ridiculous price for a tiny bit of wire mesh.