407 Hdi 2.7 oil leak (but only sometimes)

[407]

The old Hdi has been running well until yesterday.

I took it for a spin up the coast 200kms to burn off the cobwebs on the freeway and ran fine. Stopped over night and next day all well (eg no oil stains on the driveway)

Went for a short drive (10 kms) at low speed and stopped at some shops. Came out an saw a wet patch under the car (auto transmission side) and using tissue found it was engine oil (not red auto transmission oil). Not a lot but enough to concern me as its never leaked oil before (eg driveway is clean) .

Drove home the 200kms and watched the oil and temp gauges just in case a pipe burst etc but seemed fine.

Left it in the driveway with some cardboard and next day had some oil in two places, both on the auto transmission side.

Jacked up the car and had a look underneath. The auto transmission oil cooler looks fine and pipe were dry and clean.

The rest looked okay (but fairly coated in oil) but I did notice some red gasket suggesting the transmission / engine might have been pulled apart.

I'm now suspecting a leak somewhere near the engine oil filter cooler that is making in way down the engine.

The weird thing is that its not dripping oil when cold, only after it has been on a run, suggesting a pin hole leak / loose pipe or similar .

Are the oil filter cooler combo known to leak ?

I'm not aware of any external oil pipes expect maybe to the turbos (loose banjo fittings ?).

Any ideas ?

[407]

I've investigated this further and still stumped as to where the oil is coming from.

Both turbos and surrounding areas look reasonably dry / clean on the outside and not covered in oil albeit the rear one is a bit more oily than the front one.

Also removed the air pipes and all are clean, no dripping oil, including the final intake into the engine post turbo cooler. I have assumed if oil is leaking into the turbos the insides of the pipes would be oily. Also no blue smoke blowing thru exhaust

Removing the turbo air pipes, air cleaner etc, the top of the auto transmission is covered in oil and suggests its coming from above the auto transmission somewhere.

Note turbo's are below the auto transmission and no sign of oil spray.

Oil filter and diesel filter areas are above the auto transmission but seem clean, no obvious oil run visible.

The other weird thing is that it does not seem to leave a trail of oil drops when driving (walked back along the road / driveway to check), only a dump when I stop and turn it off.

[407]

Some more diagnostics

1. Oil level seems fine (eg no water or diesel in the oil filling it up) about half full on the dipstick
2. oil filter is on tight
3. I ran the engine for 20 mins (with air cond on) to see if it would show the leak but alas not
4. when running there is a bit of smoke / mist oil ? out of the oil dipstick / oil filler - seems to reduce when I plug the two air filter vacuum hoses so just assume it sucking in air
5 . at 1800 rpm with the intake hoses disconnected I get a mild metal ping noise in the rear turbo - it also seems to suck less air than the front one at 1800 rpm (sort of a known issue based on MAF readings so not sure if the turbo is an issue or the pipe is)
6. no smoke or black soot from exhaust
7. changed the auto transmission oil just in case engine oil was coming thru the oil seals - looked okay (reddish)
8. car stopped and no oil leaks

Any diagrams with the external oil pipes to check the connections ?

[407]

So its seems my oil leak turned into a water leak.

Some posts suggested the oil filter / cooler gasket might leak so I investigated this

Using a torch, I saw some liquid between the banks of the V6 (in the V)

Using my Pela pump, I sucked it up and it was all water and then some oil (I assume from past oil changes)

I suspect the water was coming for my temp repair of the 1343.HK pipe so I replace it with a new one. The O ring looked a bit weird when I pulled the old one out.

I assume the water was pooling / heating up and so when the car stopped, it overflowed and the oil ran off first.