[Dootie]

Hi I have a m57 from a 330d in my boat. Crankcase is vented through a vortex style breather feeding into a catch can. Under boost the top end appears to be flooded with oil and blows oil out every possible orafice , engine runs extremely well but refuses to keep the oil inside the engine. Ideas or help appreciated

[POBEP]

Originally Posted by Dootie

Hi I have a m57 from a 330d in my boat. Crankcase is vented through a vortex style breather feeding into a catch can. Under boost the top end appears to be flooded with oil and blows oil out every possible orafice , engine runs extremely well but refuses to keep the oil inside the engine. Ideas or help appreciated

- what is the ID of the tubes that runs to/from catch can?
- what is the catch can brand/model

[Dootie]

16mm hoses , catch can is a 3” stainless pipe with baffles about 300 long feeding to a secondary can which is about a litre with filter on top.

[BB_cuda]

This sounds familiar. Take catch can off. Clean everything out and try it.

Scubudu had sort a similar thing happen. He took the Provent off, cleaned everything out and problem went away. He was loosing almost all oil in 3-5 miles driven.

[lnxguy]

These engines do no require catch cans.

[Scubudo]

My problem was that I drained my Provent to a T off the dipstick...and decided to remove the 1 way valve in the drain line. When I did that, I sucked oil up the drain line at an alarming rate (5 miles per quart).
If your catch can isn't set up to drain back into the block, the catch can likely isn't the problem...at least, if you still have the original ccv valve on the top of the valve cover in place and are not routing the ccv back to the intake.
IIRC, there is a valve in the ccv to prevent too much suction...so I suppose it is possible that you could get enough suction from the turbo to draw oil out...but not sure.

Otherwise, if there is too much pressure in the head...and not too much suction, Iwould question if the problem may not be the VCG or failure of the CCV valve.

[Scubudo]

If the problem is too much pressure, you should be able to confirm by opening the oil fill cap and checking if there seems to be excessive pressure there.

...which reminds me that excessive "blow by" is also a plausible explanation for excessive pressure crank case pressure.

[POBEP]

Originally Posted by Dootie

16mm hoses , catch can is a 3” stainless pipe with baffles about 300 long feeding to a secondary can which is about a litre with filter on top.

16mm could be a bit narrow for M57

As others noted, consider catch can bypass, at least temporary
Measure crankcase pressure with and without catch can, under different RPM and load conditions.

The data will ether rule out catch can impact or will suggest to redesign its setup.

I use 25mm piping with Provent 200 without drain back to the engine via dipstick.
No issues with leaking oil out of the seals or anywhere else.
I measured crankcase pressure before and after install and it checked out ok.

25mm ID pipe would have 2.5x larger cross section than 16mm

[POBEP]

Originally Posted by Dootie

Hi I have a m57 from a 330d in my boat.

M57 as a boat engine IS ...

[Dootie]

Thanks for the assistance, have attached a pic hopefully it works . Yeah setup is pretty far from factory

[Scubudo]

What type of boat is that in? It looks prettier in their than it does under the hood.

Since it looks like you are venting to atmosphere and you still have the original ccv valve, you definitely can exclude too much vacuum/suction since you are not feeding into the intake.
Since it blows oil out every possible orifice, can you clarify what you mean by that? Is it blowing oil out other places besides the vent after the catch can? If that is the case, then the CCV possibly is not flowing enough to vent the crank case.
I assume the long cylinder is the vortex style breather. My understanding of how those work is that as the gasses swirl, the oil gets deposited on the walls, then flows to the lowest point. Is there a drain on the bottom, or where is this oil supposed to go? If it has no place to go, it is going to fill up and reduce venting. If there is a drain, are you feeding into the turbo drain line? If so, is there a possibility that when you tapped into the drain line that it created a partial obstruction? Do you have a one-way valve in drain line (because I suppose it is possible that the oil being pushed through the turbo drains is still at a high enough pressure to back flow up the drain line)?
Do you know anything about the history of the engine? Was it out of a wrecked vehicle? Was it rebuilt prior to installing? If not, do you know how many miles were on the donor vehicle? Was the valve cover gasket replaced?

I apologize for all of the questions, but trying to get a full picture about what factors could be causing the problem.

[lnxguy]

That is badass!

[P14kle]

+2 for Valve Cover Gasket..

[Tomnavigator]

Dootie,
My vote is too much back pressure restriction causing pressure build up. I agree with BOBEP that the 16 mm hose is too restrictive. You did not say what your filter on top of the second can is. If it is a pleated filter, then the filter can be causing the excessive back pressure. The bottom line is the overall catch can system is creating way too much back pressure. Use 25 mm ID hoses or larger and remove pleated filter and replace with open filter such as plastic scouring pad. All you need is something for the oil mist to collect on and drip down. You don't need much thickness 1/2 inch to 1 inch at the most.
I too want more info about the boat setup. Is it direct drive to the prop or does it go through some kind of gearbox. Size of boat. Speed.

[Scubudo]

Dootie,
Where art thou?