Delica Canada | Mitsubishi Van Club

Like the waste gate actuator...

Over the last couple of months I noticed a small oil spot being left by the Delica. And while on the lift the other day for changing the oil/filter I got a good look at a big mess on the back side of the engine. I had already replaced the valve cover gasket, but I snugged the bolts anyway. Cleaned up what would spray off and it looks like the oil might be coming from the inlet manifold.

The only way I can think of oil getting to the inlet manifold and waste gate actuator is turbo seals or back pressure... and I've noticed a whine from the turbo (but no significant oil smoke). I can't see a crank case breather/PCV anywhere and when I google it I get a bunch of turbo hits... I'm guessing the turbo handles that as well?

I'm thinking a new turbo might be in order, but I thought I would post here in case I'm overlooking something.

4D56 engines tend to have a lot of blowby when they get old, the oil is possibly being blown out your rocker cover and into the intake manifold. Try taking off the ribbed rubber turbo inlet pipe (the one that goes from the black steel pipe to the turbo inlet)- if that's wet with oil, then it's coming in from the engine breather, before the turbo.

If that pipe is dry, then it's a turbo oil leak. A rebuild kit or new turbo should sort it out.

FWIW I had a new head, refaced inlet and exhaust manifold, new manifold gasket, new turbo and I *still* had an oil leak from the manifold gasket. Fitting an oil separator to the engine breather pipe cleaned it up- though I have to empty the separator every 10,000km.

Thanks. I'll check the turbo inlet. Now I'm thinking it probably is blow by.

About the same time I noticed a little oil coming from the oil filler cap, figured I hadn't secured it fully or something.
It would be *almost* funny if the diesel treatments cleaned things up enough to increase blow by...

I built my own vapour separator, but I hear good things about the Pro Vent 200.

https://www.amazon.com/Mann-Hummel-6257 ... 48S2AY3_tt

Might be tricky to find room for it in the engine bay though.

A long hard drive through the mountains at highway speeds (or as close as it could maintain ) and it seems to have mostly cleared up.
I'm guessing it just got hot enough to burn it off inside and it will soon be back with around town driving. I haven't gotten around to pulling the turbo inlet yet, but the rocker cover hose was a bit wet.

I'll probably be adding a separator, but I might try a breather/filter inline first.

Just make sure whatever you fit doesn't restrict airflow from the rocker cover. If you restrict the engine's breathing, you'll pressurise the crankcase and create all sorts of new oil leaks.

Yes, I checked the pressure buildup in the rocker cover by plugging the exhaust hose with my thumb... it's pretty significant IMO. And there's a bit of white smoke so definitely some blow-by. I guess I'll pull the cover and verify/adjust the gaps to ensure the valves are closing as much as they're going to. I believe there's also a "metal sponge" type screen in there that's worth checking, but based on the amount of air exiting I don't think it's plugged.

No smoke or significant pressure buildup in the crank case evident at the dipstick tube, so the rings seem to be good.

I need it to stop raining so I can do some of this little stuff...