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[Brucie1946]

Hello,

Having read Duggs post and the responses to it, I'm convinced that the crappy plastic rocker covers are more the problem than the seals going.  I've spoken to numerous people now and they say that its non genuine parts being used or incorrect torque values, I'm not convinced!

A reputable vaux repairer told me that the plastic cam covers warp longitudinally allowing oil to seep past, either filling the spark plug holes or leaking externally, which mine is doing both after replacing the gaskets with gen vaux parts and tightening as specified.  I'm guessing this is a known fault, as my dealership has numerous pairs of plastic rocker covers in stock!

I also own a Vectra GSi with a 3.0 engine conversion, obviously this has the metal rocker covers, and hence having wider rocker seals, and has never suffered a problem, I appreciate this is different, but the breather system is almost identical, the Vectra having 2 outputs on the breather, and the omega has 3?  My Vectra I have breathing to atmosphere on both pipes, this could easily be done on the omega.

I've a few jobs to do on the omega - hbv, plugs, ht leads, 02 sensors and possibly DIS pack.

Apart from the filler being in a different position, and them being metal, I might give it a go, I've bought a pair of Vectra rocker covers.

I've been told many things to watch out for - blocked breathers (easy job to do whilst I'm doing hbv), also crank seal may start to blow?

Another good reputable chap I spoke to who services V6's, said to check the oil pressure, the oil pressure at idle should be 1.8 bar, and when revved should blip upto around 5 bar.  If its reading more than this + 5 bar, then a bleed off hole in the pump is blocked, its only 2mm in size, and becomes blocked over the years, causing the pump to pressurise the oil beyond 5 bar (i'm told the pump is capable of 10 bar) hence why the weak spots are found on the engine - rocker cover seals usually.  He told me to check it with a gauge, to see what its running at, and if beyond 5 bar to use an oil flush to clear the blockage, he again said to keep attached the oil pressure gauge and see the pressure start to drop with the flush doing its job , to return the pressure back to around 5 bar when revved.  I'm hoping this will work, as he said it has always worked for him, I'm happy to give this a go, I've got nothing to lose.

I changed the rocker seals 2 years ago now, and has started to leak again, hence why I'm looking further into it this time.

I'm happy to take criticism or advice, as were all here to learn on here from one another.

Hope this helps

Dean

[Grrrrrr]

Interesting.

There are breather 4 pipes going in the back of the plenum on my 2.6: 2 large outer ones and two smaller on the inside. One pipe is particularly small and is usually blocked.

On an old Mk 2 cavalier I had there was an oil pressure relief valve that regularly used to stick. I could see when it happened because it had an oil pressure gauge. I reckon I used to clean that about once a year. Don't bother on the Omega as no-one here has commented on it and it is more than likely a complete bar steward to get to.

Be interested to hear how you get on with the metal covers. Worth fitting an oil pressure gauge to get a heads up on these things?

Incidentally, I wondered it if would be worth leaving the clips off the breather hoses. That way the hose might blow off before anything else goes?

[Brucie1946]

theres 2 ports, one large and one small, I know the larger of the 2 is split into 2, not sure about the smaller of the 2?

Vaux guy I spoke to always runs a flush in customers cars, to remedy the problem every oil change, once a year.

Oil pressure can be checked using a oil pressure gauge , by removing the oil pressure sensor at the front of the engine, being careful not to interfere with the aux belt when engine is running so I'm told.

Will check and do all this when my broken wrist has mended itself! hehe

Dean

[feeutfo]

cleaning the breathers is all thats needed, plus the seals do go hard with age. The rest is all a bit miss informed from what i've learned on here. Although i do have first hand experience of the warped plastic cam cover theory...Utter 'dangle berries' is, i believe, the correct oof approved term.

[Abiton]

It's good to think about these things mate.
Plastic does expand/contract considerably more than metal with changes in temperature, certainly.

There are a few counter-arguments I'd suggest though.

Most times (not all, but most) when someone on here says that their recently-fitted gasket(s) are leaking, it turns out that they bought pattern parts.

A dealership will make more profit selling covers with seals than just seals. I'd imagine.

The oil pressure excess may well be true for some underloved engines, but could only affect the camcover gaskets if the camcovers were full of oil at this pressure.  My understanding is that this is not the case.

Keep thinking though. 
It would be quite neat to be able to measure the pressure on the gaskets at several places around the perimeter to see how much variation there is at full operating temperature.  This could be crudely done, I guess, by trapping some very thin bits of some sort of sheet material between gasket and head, then seeing how hard it is to pull them out at temperature.  :-/

[ScottieMV6]

Hello,

Having read Duggs post and the responses to it, I'm convinced that the crappy plastic rocker covers are more the problem than the seals going.  I've spoken to numerous people now and they say that its non genuine parts being used or incorrect torque values, I'm not convinced!

A reputable vaux repairer told me that the plastic cam covers warp longitudinally allowing oil to seep past, either filling the spark plug holes or leaking externally, which mine is doing both after replacing the gaskets with gen vaux parts and tightening as specified.  I'm guessing this is a known fault, as my dealership has numerous pairs of plastic rocker covers in stock!

I also own a Vectra GSi with a 3.0 engine conversion, obviously this has the metal rocker covers, and hence having wider rocker seals, and has never suffered a problem, I appreciate this is different, but the breather system is almost identical, the Vectra having 2 outputs on the breather, and the omega has 3?  My Vectra I have breathing to atmosphere on both pipes, this could easily be done on the omega.

I've a few jobs to do on the omega - hbv, plugs, ht leads, 02 sensors and possibly DIS pack.

Apart from the filler being in a different position, and them being metal, I might give it a go, I've bought a pair of Vectra rocker covers.

I've been told many things to watch out for - blocked breathers (easy job to do whilst I'm doing hbv), also crank seal may start to blow?

Another good reputable chap I spoke to who services V6's, said to check the oil pressure, the oil pressure at idle should be 1.8 bar, and when revved should blip upto around 5 bar.  If its reading more than this + 5 bar, then a bleed off hole in the pump is blocked, its only 2mm in size, and becomes blocked over the years, causing the pump to pressurise the oil beyond 5 bar (i'm told the pump is capable of 10 bar) hence why the weak spots are found on the engine - rocker cover seals usually.  He told me to check it with a gauge, to see what its running at, and if beyond 5 bar to use an oil flush to clear the blockage, he again said to keep attached the oil pressure gauge and see the pressure start to drop with the flush doing its job , to return the pressure back to around 5 bar when revved.  I'm hoping this will work, as he said it has always worked for him, I'm happy to give this a go, I've got nothing to lose.

I changed the rocker seals 2 years ago now, and has started to leak again, hence why I'm looking further into it this time.

I'm happy to take criticism or advice, as were all here to learn on here from one another.

Hope this helps

Dean

Could it not be that yours were already warped before this change and that is why they are still leaking

[Elite Pete]

I've changed numerous and cleaned the breathers at the same time and never had a problem.

[Brucie1946]

thanks for getting back.

its worth a shot though, the guy I spoke to works at vauxhall, used to build the V6 at ellesmere port as it happens, so knows the engine inside out.  Its just something he recommended, and something he does every time he services a vectra or omega.

each their own as they say.

just thought I'd share with everyone what I'd heard, maybe helping someone along the way.

Dean

[Entwood]

I've had 2 omegas now ... both with close to 100,000 miles .. and both on original plastic camcovers with no problems, once the gaskets are done PROPERLY and the breathers kept clean.

If this was such a major problem we all would have changed the gasket covers long ago, and VX would have done so well before the end of the omega's life.

There are many omegas with far higher miles on the forum .. all still with the plastic covers ... they can't be that bad .... but they can be incorrrectly fitted and/or fitted with pattern gaskets .. 

Another consideration is that the cam covers act like a "safety valve" in case the breathers get blocked .... I'd rather the cam covers popped and leaked than the crank seal did !!

[Kevin Wood]

Agreed with most. Main cause of leakage is blocked breathers and failure to clean adequately after gasket failure, or use of poor quality pattern gaskets.

Oil pressure will make no difference to the cam cover gaskets. Only the internal oilways, filter, cooler, bearings and lifters are subject to the oil pump output pressure so it has no direct bearing on the cam cover gaskets.

Pressure can only build up behind these seals as a result of blocked breathers.

Kevin

[Brucie1946]

How does the Vectra differ then, you'd expect them to suffer with crank seal leaks would you not?  I have both and the Vectra behaves itself.

same engine, only run metal covers due to inlet manifold support fixtures attached to rocker cover.

just searched the net, seems vectra c 3.2 owners suffer the same!  bad design in my opinion.

just a thought.

[Entwood]

How does the Vectra differ then, you'd expect them to suffer with crank seal leaks would you not?  I have both and the Vectra behaves itself.

same engine, only run metal covers due to inlet manifold support fixtures attached to rocker cover.

just searched the net, seems vectra c 3.2 owners suffer the same!  bad design in my opinion.

just a thought.

nope .. bad servicing .. 

[biggriffin]

i agrre with all of the above regarding cam cover gaaskets and orings. and yes you can fit vectra metal covers on omega havnt done any but have seen a few.