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[dublin.jd]

Higher crankcase pressure forces oil out through any gaps/weakspots. The higher the crank pressure, the more oil gets forced out. Absolutely nowt to do with oil pressure

Blow through a straw into a full glass of water and watch what happens...

How is the pressure transfered from crankcase to the cam covers? If not through the oil?

[05omegav6]

Via the channels which drain the oil back to the sump

Breather system only exists to feed crankcase fumes back into the clean side of the engine for combustion, rather than venting to atmosphere...

A new fangled idea from the mid seventies deliberately venting to atmosphere might actually be illegal

[dublin.jd]

Via the channels which drain the oil back to the sump

Breather system only exists to feed crankcase fumes back into the clean side of the engine for combustion, rather than venting to atmosphere...

A new fangled idea from the mid seventies deliberately venting to atmosphere might actually be illegal

Excellent ! Can't believe I didn't think of that.
I still think adding pressure relief valve would benefit, at least as a fail safe as leaking oil everywhere can't be legal either?
Thanks for the light bulb moment.

[dublin.jd]

Entwood, thanks for taking the time to explain that so well. and I see what ur saying. But don't see how the pressure in the crankcase is related to the cam covers other than through oil pressure? and not vacuum.
Again I'm keeping an open mind.
Thanks

The oil pressure in the cam covers is zero .. oil pressure ONLY exists in oil ways, drillings, pies etc .. once the oil is sprayed onto a surface, like a cam lobe, the pressure is zero.

Within the cavity that is the cam covers/crankcase there is only air pressure, this increases with the effect of gas blowby from the compression/combustion pressures leaking past the piston rings, and is decreased by the effect of the breather suction we are discussing. The actual "atmosphere" within the crankcase/cam covers cavity comprises a mix of blowby gases/oil mist/water vapour.

If the pressure builds up due to blocked breathers, we know the cam cover gaskets are the weakest link, so they fail and leak the "atmosphere" from within to without ....   the blowby gases will simply escape, the water vapour will evaporate fully, the oil mist will condense and stick to any surface it can, then run and appear as a leak. If the cam cover gasket hole is large enough some of the lubricating oil spray from within may well leak out directly through that hole.

The answer is to maintain the slight negative pressure that the "vacuum" from the plenum causes via the breather system, this will "suck" the "atmosphere" out along the breather pipes until it gets burned back in the cylinders ... unfortunately for us .. the temperature change from a hot crankcase to a cold(ish) plenum cause the oilmist to condense as the horrible emulsified mess that we get, that if not cleaned out blocks the airways we want to do the job !!

Thanks to u too entwood again for going in to detail. It makes sense now after reading previous post. 

[Sir Tigger KC]

I wonder if the pressure relief valve might be as simple as drilling a small hole in the cam cover and plugging with 'goo', creating the weak spot that might save the gaskets if the breather system becomes blocked.... 

I guess it would take a lot of trial and error to find out. 

[dublin.jd]

Let's say I put Schrader valves on each cam bank and removed the inner part and then screwed dust caps on them. Say with a pin hole in each cap. Surely the engine would produce more than enough vacuum to compensate for what would be lost through the pin holes? And not cause a fuel trim problem?

[dublin.jd]

Thanks SirTigger,
That's what I'm looking for! Constructive ideas.
Thanks

[chrisgixer]

Here's an idea, a constructive one too, fix the car and run it without issue like everyone else

[05omegav6]

I still think adding pressure relief valve would benefit, at least as a fail safe as leaking oil everywhere can't be legal either?

If it's leaking onto the manifolds it's an MoT issue

[dublin.jd]

Here's an idea, a constructive one too, fix the car and run it without issue like everyone else

Thanks for that  but again ur missing the point, and remember my first post? It said try not be sarcastic 

[dublin.jd]

I still think adding pressure relief valve would benefit, at least as a fail safe as leaking oil everywhere can't be legal either?

If it's leaking onto the manifolds it's an MoT issue

I can put dust caps on the valves without pin holes for the mot 

[chrisgixer]

Here's an idea, a constructive one too, fix the car and run it without issue like everyone else

Thanks for that  but again ur missing the point, and remember my first post? It said try not be sarcastic 

Seriously though, save yourself the agro, get it working correctly, first.

One thing bothers me though. All this oil escaping, but no misfires. Usually the oil runs into the spark plug wells and destroys the ignition system. Yet there's no mention of miss fires.

Makes me wonder if the oil is escaping elsewhere. In which case, no amount of modding cam covers will be relevant, if, for example, the sump is leaking, or the oil pump, or the dip stick tube, or the oil pressure or level sensors, or the front crank seal.

Sorry but there's way too many questions unanswered as to the actual fault, to even consider weather what your suggesting will help (it won't) the faults you posted yourself.
You still haven't confirmed if the breathers are actually clear to blow through, with an airline or whatever.
Still haven't confirmed if its the cam covers leaking.
Still don't understand how the system works.
Yet still want to alter it anyway.

This is not logical captain.

[dublin.jd]

I understand how it works now thanks to the people on here.
All hoses, breathers etc are clear. I also cleaned breather box but didn't take it off and open it up. So maybe that something to do when replacing gaskets. As there's 98k on clock and nothing to suggest they've been done before.
I have no mis fire but have 0170 and 0173 fuel trim codes.
Could they be caused by leaking cam covers?
I've had other omegas, all petrol. (2 x 2.5's and now a 2.6) with leaking c covers but no fuel trim codes? (not as bad as this one though)
It's defo c covers leaking as there's oil on heads and burning oil smell due to exhaust manifold. Luckily enough there's no oil in plug wells (a first for me)
When I get around to doing the gaskets I would also like to add a fail safe just to be sure. (Obviously after I get it 100%)
That's all.
I do appreciate all the comments.

[Steve B]

Imagine someting like a one way valve on the rocker cover or covers that lets pressure out,just before the gasket blows,and triggers a warning light to warn us. (clean your breathers)

Think that is what the OP means..

Time to strip down the wifes pressure cooker 

[dublin.jd]

Imagine someting like a one way valve on the rocker cover or covers that lets pressure out,just before the gasket blows,and triggers a warning light to warn us. (clean your breathers)

Think that is what the OP means..

Time to strip down the wifes pressure cooker 

Thanks, I don't feel weird when other people understand what I'm saying