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[terry paget]

I am currently changing the cam cover gaskets and cleaning the breathers on my recently purchased Omega 2.6. I thank Marks DTM Calib for his excellent guide.

It has dawned upon me that in a 'fit' Omega the function of the cam cover gaskets is not to contain the oil, it is to prevent air being sucked in, the cam cover interior, along with the whole breather system and the sump, being under light vacuum.

So long as this state of affairs exists there is no risk of oil leakage, oil in plug holes, misfiring, smell of burning oil in the cabin. Things go wrong after several years of use, perhaps infrequent oil changes, sump overfilling. Oil spray sucked up by the breathers clogs the breather system, commonly the small breather hole. Once this happens the sump, cam covers and much else will run under pressure, not modest vacuum. It will not blow up like a balloon. but the pressure will find a way out somewhere, at the cam cover gaskets, oil filler cap, crankshaft oil seals, or elsewhere.

In the past I have suffered leaking cam cover gaskets, with symptons of oil smell in cabin, oil in plug holes and consequent misfiring. I have with great care changed the cam cover gaskets, using only Vx gaskets on this forum's advice, but not paid much attention to the breathers. I now realise my error. All I needed to do was clear the breathers. Then instead of blowing oil out the engine would suck air in.

I reckon that the above symptons should be cured simply by clearing the breathers without changing the cam cover gaskets. Has anyone ever tried this?

[05omegav6]

All well and good until you inadvertently warp the covers by overtightening the bolts... the seals eventually go hard and brittle over time too.

But keeping the breathers clean on top of new covers/seals is a worthwhile prevention exercise

[Kevin Wood]

Yep, poor breather maintenance is not the whole problem, but cam cover gasket problems would be rare if all breathers were kept clear.

Another check to add to the pot: Mine failed at 120K due to the cam cover bolts working loose.

[05omegav6]

Would it be safe to add cam covers to the long term shitlist service items along with wishbones/shocks/subframe bushes etc that most Omegas require at point of initial purchase

[Webby the Bear]

They will fail at some point even if you keep your breathers clean. They get super brittle.... I changed  Zafira gasket a few weeks back and it was as hard as the plastic on a biro pen 

But as said, breather cleaning should stop early failure.

[chrisgixer]

Assuming the engine is never turned off, then yes there is an element of logic, but a seal is a seal. Or in this case, a gasket. Gaskets should seal. If they did let air in, the crank case wouldn't be at the desired vacuum.

Clean breathers and fit gaskets as the guides.  Sorted.

[Webby the Bear]

Assuming the engine is never turned off, then yes there is an element of logic, but a seal is a seal. Or in this case, a gasket. Gaskets should seal. If they did let air in, the crank case wouldn't be at the desired vacuum.

Clean breathers and fit gaskets as the guides.  Sorted.

 

[Andy A]

A friend asked me today, if the breather pipes were blocked would this lead to leaking cam covers and would it cause smoke from blow by to come out from the filler tube when engine is running and cap is taken off?

Thanks

[Andy A]

A friend asked me today, if the breather pipes were blocked would this lead to leaking cam covers and would it cause smoke from blow by to come out from the filler tube when engine is running and cap is taken off?

Thanks

Found the answer for him. Yes blocked breathers will cause this.