Crankcase ventilation.

[Trunksie]

Hey Legends new to this forum and was trying to chase info on crank case ventilation.

Ive got a 25 d350 and im planning on keeping it atleast ten years, im putting in a larger pwr intercooler and an auxiliary trans cooler because i tow a 2 ton camper a couple of times a month, ive put about 20,000kms on it since I got it 6 months ago.

Every modern vehicle ive owned ive externally vented the crank from the lowest point possible with a reed valve, one way valve, because im not a big fan of gases re entering my intake but there are other benefits of scavaging aswell.

Has anyone done an external vent or knows of who has, I can't find any info.

Thanks

[Graeme]

I can't answer your question but have you looked into disabling EGR as generally, exhaust gasses combine with any oil vapour to clog the inlet tract. However the interaction of EGR and DPF burns could mean that disablig EGR isn't an option on these engines.

IMO towing 2 tonnes with a D300/D350 shouldn't require any modifications.

[scarry]

Doing those sorts of mods may/will also be an issue while the vehicle is under warranty,in case it has any warranty issues,no matter what the issues are.

Also same as Graeme has said the vehicle should easily drag that sort of weight around with no mods.

[oldyella 76]

I tow a 2.8 t viscount with a 225 D350 with no problems, last year up Darwin/Kununurra areas the engine never went above normal but not sure of the transmission temps though. The D350 handled it with ease.

[Trunksie]

The EGR can be electronically disabled and enabled with no record.

The issue is blowby through the rings and down stroke pressure.

So at the moment when the piston travels down increasing pressure in the crankcase. The crankcase is vented through internal tubes through the block into the heads then into the inlet manifold.

The blowby through the piston rings mists the oil and that is what travels up to the inlet manifold.

So the egr let's in burnt gases into the inlet and the crank ventilation let's engine oil into the inlet manifold.

External crank ventilation it goes through a one way valve straight to atmosphere.

This eliminates pressure So the piston down stroke isn't fighting pressure and engine oil isn't entering the combustion chamber.

The reed/one way valve allows for consistent oil scavaging.

The auxiliary trans cooler will give the trans a longer life.

I also drive mine like a sports car and I tow pretty regularly at 2 tonnes and all 7 seats filled with the family.

[Blknight.aus]

The issue is blowby through the rings and down stroke pressure.



ummm, unless IVe forgotten something important, its not a isolated journal engine, single, dual or triple. When one pistons coming down another is going up downstroke pressure is negligible.

Dont faf with the ventilation by porting it in ways it wasnt designed to be ported, fit a provent or similar into the system using existing portings.

[Trunksie]

Sorry yes the pressure is close to balanced.

But blow by still increases pressure and misting and i don't want it in my intake

[BradC]

Just do it and let us know how you get on.

[Trunksie]

RAM 1500 (ZF 8HP70 / 8HP75)
BMW X5 30d / 40i (ZF 8HP)
BMW X6 30d / 40i (ZF 8HP)
Jeep Grand Cherokee (ZF 8HP70 / 8HP75)
Audi Q7 3.0 TDI (ZF 8HP)
Audi Q8 3.0 TDI (ZF 8HP)

These all use the same trans as the disco and all have issues with overheating when towing.

The ram is renowned for overheating the trans and causing failure.

The fix is always an aux trans cooler

[shack]

The issue is blowby through the rings and down stroke pressure.

So at the moment when the piston travels down increasing pressure in the crankcase. The crankcase is vented through internal tubes through the block into the heads then into the inlet manifold.

I'm having one of those days, so please excuse me...

But how does the blowby get into the inlet manifold?

I can only think of one way and it isn't this.

Again, I'm having one of those days.


Anyways, old school tech would suggest fitting a Provent or oil catch can, but this goes in well before the inlet manifold.

The only really issue with blowby into the intake, is on intercooled vehicles as the mist gradually blocks the intercooler.

The EGR however CAN lead to reduced engine life.

[Graeme]

Shack, you are indeed having one of those days as the vehicle has a D350 engine which has a turbo, into which the crankcase vents.

[TonyC]

RAM 1500 (ZF 8HP70 / 8HP75)
BMW X5 30d / 40i (ZF 8HP)
BMW X6 30d / 40i (ZF 8HP)
Jeep Grand Cherokee (ZF 8HP70 / 8HP75)
Audi Q7 3.0 TDI (ZF 8HP)
Audi Q8 3.0 TDI (ZF 8HP)

These all use the same trans as the disco and all have issues with overheating when towing.

The ram is renowned for overheating the trans and causing failure.

The fix is always an aux trans cooler

But does the D5 have an overheating problem?
I'm not saying it doesn't, but just because the 8HPXX overheats in a Ram doesn't mean it will in Land Rover.
Have you plugged in an OBD II reader and looked at the gearbox temps?
And don't forget to get it serviced at a reasonable interval, not what the book says, particularly if towing.

Tony

[shack]

Shack, you are indeed having one of those days as the vehicle has a D350 engine which has a turbo, into which the crankcase vents.The OP was making it sound like it fed directly into the inlet manifold. I still don't think this correct, I'm guessing it feeds in BEFORE the turbo, all turbo diesels I've worked on do that. So a Provent or similar would suffice.

If indeed it does feed into the inlet manifold inside the head somehow I'd be interested to know how that works, especially in a turbo diesel where inlet manifold pressure would usually be higher than crankcase pressure.

Am I correct or has tech gone past me?

It's quite possible it has!!

It's quite likely I've misread the whole thing anyway.

[scarry]

RAM 1500 (ZF 8HP70 / 8HP75)
BMW X5 30d / 40i (ZF 8HP)
BMW X6 30d / 40i (ZF 8HP)
Jeep Grand Cherokee (ZF 8HP70 / 8HP75)
Audi Q7 3.0 TDI (ZF 8HP)
Audi Q8 3.0 TDI (ZF 8HP)

These all use the same trans as the disco and all have issues with overheating when towing.

The ram is renowned for overheating the trans and causing failure.

The fix is always an aux trans cooler

If the auto is locked up a larger trans cooler may help,although i have never heard of a ZF 8HP overheating in a LR.
If the auto is not locking up at times, due to the way it is set up and programmed by the manufacturer,in those vehicles,a larger trans cooler may not help.
Tuning the auto is then the answer,which is easily done and common in some of the Jap 4X4 vehicles,so the auto is locked up more often.

[Graeme]

The crankcase certainly doesn't vent directly to the inlet manifold, with the usual method having it T'd into the primary turbo inlet stream eventually ending-up in the inlet manifold to combine with exhaust particles to form gunk. I obvously don't know if the OP thought that it does vent directly into the inlet manifold or he just took a short-cut in describing the path.

My preference is to stop EGR in normal operation rather than install a Provent although with the exhaust gas reportedly sourced from after the DPF, perhaps there's minimal carbon particles to mix with crankcase oil and therefore intake gunk might not be such an issue with the Ingenium engines.

Edit: I'd like to know where the EGR filter is located and how accessible it is for cleaning or replacement.

Edit 2: The EGR filter reference might only be for the 4-cylinder 2.0L.

[Trunksie]

Combustion happens in the cylinder and cylinder pressure spikes.
A small amount of gas leaks past the piston rings (even on a healthy engine). That leakage is blow-by.
Blow-by enters the crankcase (the space around the crankshaft inside the engine).
That gas pressurises the crankcase and picks up oil vapour / oil mist as it swirls around.
The engine’s PCV / crankcase ventilation system gives that pressure a controlled way out:
Through a breather/PCV outlet on the rocker cover/valve cover or crankcase.
The flow usually goes through some form of oil separator / baffle / cyclone separator (built-in to the cover or a separate unit) to drop out larger oil droplets.
The remaining vapour/gas travels through a PCV hose toward the intake system.
Intake vacuum / turbo inlet suction pulls it along:
Naturally aspirated: manifold vacuum draws it in.
Turbo/diesel: suction at the turbo inlet (pre-compressor) and/or a regulated PCV path moves it.
The vapour re-enters the inlet tract (commonly into the intake manifold on petrol, or into the turbo inlet/intake piping on many diesels).
Once back in the inlet, it gets mixed with fresh intake air and goes through the engine again—sometimes leaving oil film in pipes/intercooler/manifold (especially if there’s lots of blow-by or weak separation).

[Graeme]

AI rears its head again...

[BradC]

I'm wondering who is hiding under the bridge. "Trip, trap, trip, trap! "

[Trunksie]

Combustion happens in the cylinder and cylinder pressure spikes.
A small amount of gas leaks past the piston rings (even on a healthy engine). That leakage is blow-by.
Blow-by enters the crankcase (the space around the crankshaft inside the engine).
That gas pressurises the crankcase and picks up oil vapour / oil mist as it swirls around.
The engine’s PCV / crankcase ventilation system gives that pressure a controlled way out:
Through a breather/PCV outlet on the rocker cover/valve cover or crankcase.
The flow usually goes through some form of oil separator / baffle / cyclone separator (built-in to the cover or a separate unit) to drop out larger oil droplets.
The remaining vapour/gas travels through a PCV hose toward the intake system.
Intake vacuum / turbo inlet suction pulls it along:
Naturally aspirated: manifold vacuum draws it in.
Turbo/diesel: suction at the turbo inlet (pre-compressor) and/or a regulated PCV path moves it.
The vapour re-enters the inlet tract (commonly into the intake manifold on petrol, or into the turbo inlet/intake piping on many diesels).
Once back in the inlet, it gets mixed with fresh intake air and goes through the engine again—sometimes leaving oil film in pipes/intercooler/manifold (especially if there’s lots of blow-by or weak separation).