Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 15 March 2012, 12:28:14
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For a while my MV6 was leaking from the camcovers - stank when hot.
I changed these for gen GM gaskets, fitted with correct sealant and squeaky clean breathers. I also manually cleaned the engine afterwards as best as I could.
The oil stink went away, but even 2k miles later, there is still a whiff.
I had a good look at this from underneith (while I had the gearbox and cats off) to see if I could determine where it was coming from.
There seems to be oil dripping off the bolt heads of the heat sheild on the UNDERSIDE of the 2-4-6 exhaust manifold
There is also some dripping from the oil filter housing, and some where the bellhousing meets the engine
I keep my engine oil changed very often, and it's clearly nice golden engine oil, not red ATF.
I've taken off the plenum and the inlet gubbins and checked the oil cooler unions in the V - they are all dry as a bone. From the rear of the engine, with the gearbox off, I can see nothing leaking down the back.
Does anyone have any other instinct as to what this leak might be?
It's not big enough for the level to radically drop or leave puddles on my drive, but it is enough to cause an annoying whiff of oil now and again, which is driving me nuts!
The usual culprits I think are all eliminated.
Just thought I'd share in case anyone else has come across it..
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I can't think of much except cam covers that could leak from as high as the exhaust manifolds.
Are the oil cooker pipes by the oil filter sound? Is the oil filter housing leaking?
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Cooler pipe to block unions? That's where my engine weeps at the moment, the other union is maybe cross-threaded :-\
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Is the oil filler neck correctly seated ??? if not it may leak from the base when engine running ???
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Is the oil filler neck correctly seated
Yep :y
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I am convinced that it ws secret design built into all Omegas when new.
They leak oil and no matter how hard you try and seal/stop/plug every possible orrifice and fit genuine gaskets /sealant etc they are just going to leak something,somewhere.
My car has covered over 200k and for the 165k of my ownership it has leaked oil/coolant and also atf albeit it in very small quantities.I keep a very close eye on all levels and they never really drop much but are regularly topped up and replaced with new as per service schedule.
Think its just one of those things and can almost drive you crazy trying to stop them.I gave up a long time ago and unless it is causing a major issue and having a secondary effect elsewhere I would be inclined to just live with it .At least it stops them rusting away any quicker. :y
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Other than possibly leaking o rings in the oil filler neck(easily fixed by plugging the filler cap in instead) without seeing it, I'd have though this would just be residue left from the cam covers, no?
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What's the oil pressure like at idle and high revs? Doesn't really matter what seals and gaskets you replace if the oil pressure relief valve is stuck.
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I had the oil filler tube leaking last week after changing the spark plugs I thought I had disturbed the cam cover some how but after taking the filler off again and turning the O ring over the leak has stopped even thought it does not feel as tight as when I originally took it off
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Taking mine to workshop tomorrow in attempt to find where an oil leak is coming from.seems to be below oil filter, crank sensor level, as said in another post not enough for a pool of oil but annoying. Did you locate your leak
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You might find the 2 oil cooler pipes above the filter are leaking.
I had a similar leak and always thought the oil filter was loose but could never understand why but on closer investigation the crank sensor was also quite wet.Got crows foot spanner on the oil feeds and found they were both slightly loose..gave them both a slight nip up and had no further problems since.
In that area only other thing is those cam covers,but you think it is below the oil filter ?
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Thanks Amba will look in that area tomorrow.
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Crank sensor seal ok? seen them leak from there before
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Not to be a doom merchant James :-\
But when you changed the gearbox, did you remove the flywheel? Any oil at the bottom of the bellhousing is most likely to have come from the crank seal :'( If there isn't an obvious leak from the top of the bell housing then sadly there's only one place left to look... at least the downpipe bolts should undo easily enough :-\
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I would also be checking the oil cooler to block joints as already said by others, do you know if its had an oil cooler change per at some point per chance....
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Fit vectra v6 cam covers, much more robust, 3x as thick a rocker cover seal.
Did mine this way and is oil drip free now
No matter what people say, plastic warps under extreme heat conditions, can you expect a plastic cam cover to hold up to 100 deg c temps daily over the years and not warp, especially when the wall thickness around the seal on the omega is only approx 2mm, and expect that to not degrade over continuous heating up and cooling down.
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There is a constant debate re Veccy covers.
My personal opinion is they are fine to fit as long as the breathers are religiously kept clear BUT some are of the view that it's better to have plastic ones which can blow, should the breathers get blocked, rather than lose a crank seal etc etc... which is also valid..
I'm pretty neutral in that debate, but I will say one thing...
... I fitted genuine GM gaskets to a 2.6 vectra with metal covers not long ago, and the gaskets were VERY ill fitting.... much too loose!
If using veccy covers, I'd almost say try for Elring gaskets or similar... as the GM ones don't seem to fit right...
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Debate all day long
Worked for me, my omega mechanic who's employed at ellesmere port Vauxhall, and worked at the v6 engine plant on retrofits, customer issues and finding remedies for the v6's engines problems said fine to fit. Common problem is not so much the breathers, as careful maintenance and regular oil changes keeps the pipes from crusting up, pipes were perfect on my 60,000 mile car. Its the pin hole oil pressure relief orifice in the pump that gets blocked, causing the oil pump to over pressurise, capable of twice what the engine needs, running a oil system cleaner helps clean it and hence the pressure drops. On later cars not v6, the orifice was made larger, so it didn't block as easily.
Being a fellow omega mechanic specialist james, I assume you knew this already?
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James
For reference give this website a try, really helpful for queries you might have about the engine etc of the Vauxhall V6
www.v6technicians.co.uk
Geoffs a really nice, helpful guy.
I'm sure he'd be able to help you James
more power to the elbow and all that!
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The oil feed to the cylinder head is in the rear corner of the head. I don't know of any cases of oil leaks occuring due to the head gasket but if you are eliminating all possible causes it is one more thing to check.
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I had oil leaking from somewhere underneath the main block and slight smears on the rocker covers but no real indication from where. I took it in for a check and the Oil Pressure Switch was the source of the leak. It was replaced on the spot by my local garage in Bedford. Could be serious if left apparently. Seems OK now.
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No don't fit Vectra Cam covers, if they are so much better why were they not fitted at the factory? ::)
I'd rather be changing cam cover gaskets rather than a crank seal, if you maintain everything right standard cam covers and gaskets will easily last 7 years+ - My 2000 plate 2.2 is on 160k and its only had its cam cover replaced once!
Similar story with mother T's 3.0, one set of gaskets in its life time.
Part of the problem is the monkeys at Vauxhall dealers who do the work!
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very interesting Tunnie how often do you clean the breathers on your V6
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very interesting Tunnie how often do you clean the breathers on your V6
Don't know about Tunnie .. but I do mine every other oil change, so every 10,000 miles.
Since I did the rocker covers just after buying the car I've done 45,000 miles (car now has 110,000) and no problems with the cam covers whatsoever.
Original covers, but with genuine gaskets, torqued to 8NM, and the breathers kept in good condition .. :)
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I find it's not cleaning breathers it's more regular oil changes, change it every 3-5k and it does no degrade enough to cause any issues
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When I got my first Mig I thought about adapting the covers and putting in extra breathers. Nearside is easy as it has the oil filler neck the offside may take a little thought. I never did follow it up though
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When I got my first Mig I thought about adapting the covers and putting in extra breathers. Nearside is easy as it has the oil filler neck the offside may take a little thought. I never did follow it up though
Good job too. Seen a few lash ups on omegas. Non take into account that the breathers are connected to the plenum chamber, which runs at vacuume. As Master pointed out on here, the breather system keeps the crank case at negative preassure, so there's no "sides" involved.
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Debate all day long
Worked for me, my omega mechanic who's employed at ellesmere port Vauxhall, and worked at the v6 engine plant on retrofits, customer issues and finding remedies for the v6's engines problems said fine to fit. Common problem is not so much the breathers, as careful maintenance and regular oil changes keeps the pipes from crusting up, pipes were perfect on my 60,000 mile car. Its the pin hole oil pressure relief orifice in the pump that gets blocked, causing the oil pump to over pressurise, capable of twice what the engine needs, running a oil system cleaner helps clean it and hence the pressure drops. On later cars not v6, the orifice was made larger, so it didn't block as easily.
Being a fellow omega mechanic specialist james, I assume you knew this already?
I have heard mention of the issue but have not personally come across one suffering from it.
Cam cover Issues are usually caused by "vauxhall dealers" not cleaning breathers. I have yet to see one of these phantom "warped" covers from heat alone. Anyone else? Overtightening, perhaps, (again by VX mechanics), but not heat.
We'll agree to disagree.... I am with Entwood, metal covers are a bodge, ie, not fixing the route cause of the issue.
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Debate all day long
Worked for me, my omega mechanic who's employed at ellesmere port Vauxhall, and worked at the v6 engine plant on retrofits, customer issues and finding remedies for the v6's engines problems said fine to fit. Common problem is not so much the breathers, as careful maintenance and regular oil changes keeps the pipes from crusting up, pipes were perfect on my 60,000 mile car. Its the pin hole oil pressure relief orifice in the pump that gets blocked, causing the oil pump to over pressurise, capable of twice what the engine needs, running a oil system cleaner helps clean it and hence the pressure drops. On later cars not v6, the orifice was made larger, so it didn't block as easily.
Being a fellow omega mechanic specialist james, I assume you knew this already?
Please explain the relevance of the section highlighted. The pressure in the high-pressure oil system seems to me utterly irrelevant to camcover seals. :y
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Due to the fact the oil pump has a pin hole orifice, which can get blocked in some cases, this acts as a bypass whereby if the pump creates excess oil pressure a ball bearing type poppet allows oil past through the orifice, hence venting pressure. If this orifice is partially blocked, the oil pump is more than capable of creating double the amount of pressure that the engine requires. Excess oil pressure finds the natural weak points, cam cover gaskets, crank seal etc.
Im readily informed of this issue from the mechanic at
www.v6technicians.co.uk
Im sure he knows what he's talking about having worked at the V6 engine plant, would you not think? I think its feasable!
Run an engine oil flush every oil change, with an oil pressure gauge connected you can actually watch the oil pressure coming down, as the flush cleans the oil pump pressure relief orifice.
Hope this helps explain.
If in doubt, give the v6 technicians a shout, who will back the story up, please remember these 2 guys worked at ellesmere port rectifying issues, building and testing the 2.5, 2.6, 3.0 and 3.2 engines. Geoff is a extremeley knowledgable chap.
Enough said, you can lead a horse to water, but you can't make it drink!
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mmm can you explain to me how excess oil pump pressure works in a negative pressure void ???
The cam covers are an open void internally .. so oil pressure there would be non-existent under most circumstances .. as the crankcase is held at a partial vacuum , by the action of the breathers, then there is even less reason for such a happening !!!
Pumps don't produce pressure BTW ... they produce flow, the resistance to which is pressure - simple but basic physics.
There is a lot of data around - should you care to research it properly - regarding the use of oil flushes on old engines .... it can actually (and usually will ) do more harm than good.
You comments about the oil flush cleaning the pump, and the results being visible at the pump outlet are true ... as the pump is cleaned the flow will increase; the outlet is a fixed restriction and as such causes pressure, if the flow through a fixed orifice increases the pressure at that orifice will also increase.... again simple physics.
As already said .. the relevance of all that to cam cover gaskets is precisely ... ZERO
:) :)
You can wish as much as you like .. but you can't change the laws of physics ... :)
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Thankyou for your reply entwood
You sound a very learned chap, an engineer perhaps?
I dont wish to explain any further, because I dont have a problem with the information given.
Feel free to contact the v6technicians if you need any further clarification.
Must go and walk the dog now!
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My first 3.2 suffered with tappet noise and when tested with a pressure gauge it was suffereing pressure switch issues. The car was taken to Geoff and Pete (V6Technicians) who worked on the Ellesmere Port V6 Production line in all areas and know the engine inside out, they used an engine flush and the tappet noise was instantly resolved and the pressure was brought back down to within the original limits.
The advise they gave me was to change the oil regularly and run an engine flush through it every 12 months / 12K miles. I stick by that advice to this day. If you use the flush at regular intervals I see no issues, however I wouldn't use it on a high mileage engine that the history is unknown on.
So many 3.2's and 2.6's that i've heard suffer noisy top ends due to VX / GM's 20K - please the fleet manager - service regimes, unfortunately the bit people don't read is the 'OR ONE YEAR' statement.
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You comments about the oil flush cleaning the pump, and the results being visible at the pump outlet are true ... as the pump is cleaned the flow will increase; the outlet is a fixed restriction and as such causes pressure, if the flow through a fixed orifice increases the pressure at that orifice will also increase.... again simple physics.
Flush cleans the pressure valve that sticks causing higher pressures than the engine was designed for ;)
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You comments about the oil flush cleaning the pump, and the results being visible at the pump outlet are true ... as the pump is cleaned the flow will increase; the outlet is a fixed restriction and as such causes pressure, if the flow through a fixed orifice increases the pressure at that orifice will also increase.... again simple physics.
Flush cleans the pressure valve that sticks causing higher pressures than the engine was designed for ;)
and that relief valve is in the pressure line to the various journals, bearings , gears etc .. it is nowhere near the crank case covers !!!
The "engine" wasn't designed to take any pressure, the oilways and the items fed by them were.... :)