D24T oil leak

[Ian47]

Hi, I have D24T in my boat, there is an oil leak at the front of the engine. It is very difficult to access the area in order to identify the cause. The oil can be seen running down behind the timing gear back plate just below the water pump.
I replaced the front crankshaft seal last year and the rocker cover gasket twice, the last time I used instant gasket at the front and rear joints.
My question is:- Is there anything other than the front camshaft seal that could cause a leak? I replaced the timing belts and tensioner when I did the crankshaft seal.
I assumed that as the oil wasn't being thrown out the seal would be OK, but it seems the only thing left.

[ngoma]

Most common are leaks from the valvecover gasket, especially if it's the 4-piece rubber/cork type, which almost guarantees a leak, goop or no goop. Also, if the studs are not bottomed out, their shoulders sit up too high and won't provide a good seal when the nuts are screwed all the way down.

Headgasket could also leak oil down the block, more common in the middle, under the vacuum pump, but also possible at the front.

Only good way to identify the source is to clean up the area well, run the engine, and inspect for new evidence of leaking oil, keeping gravity in mind. In your case you may be limited to using a strong flashlight and telescoping inspection mirror?

[Ian47]

Thank you for the quick response. The timing cover backplate hides the source of the leak even with a mirror and light, but you're right it could be the cylinder head, is there an oilway near the front feeding the camshaft? I have not had the head off one of those engines. I have changed the valve cover gasket twice and the leak hasn't altered so I don't think it's the cover. A second query, the oil pressure I think, used to be about 60 psi, I changed the oil cooler pipes two or three years ago and I noticed that it doesn't come above 30 psi warm now. The green book says the relief valve spring should be 49mm, this one measures 52.50mm, do you have any ideas what I could check for?
Thank you.

[ngoma]

1) What style valvecover gasket?

2) Are the studs screwed all the way down?

3) What oil pressure gauge/sender are you using?

[Ian47]

It's a 4 piece cork and rubber gasket.
The studs have a shoulder which protrudes about the gasket thickness.
The oil gauge is fitted to a home made tee which carry's the sender unit for the light and the coupling for the gauge pipe.

[ngoma]

Originally Posted by Ian47

It's a 4 piece cork and rubber gasket.

Known leakers!!! Get the rubber one-piece. No need for goop. Make sure the VC sealing surface is not dented or warped and make sure the studs are screwed in all the way into the head.

Originally Posted by Ian47

The oil gauge is fitted to a home made tee which carry's the sender unit for the light and the coupling for the gauge pipe.

Can you substitute another sender/gauge to verify the true oil pressure?

[Ian47]

Thank you for your help, I will check the studs and verify the gauge, that's a good idea. I have not seen the rubber 1 piece gaskets on any of the sites I look at, do you know where to find them? I am going to be busy elsewhere for a couple of weeks so I may not have answers right away.