Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: uktigger on 03 September 2012, 17:08:27
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I have a 2.2 2004 Omega - z22xe to be exact and when the engine is cold, it makes quite a noise, tapping, which i'm assuming is the hydraulic lifters.
after about 10-20 secs this noise stops and the engine runs normally.
I have been told that this is because the oil is draining down away from the top of the engine when it's left for a period of time, which could possibly be caused by the oil pressure relief valve sticking.
Does anyone have any opinions on this theory, and if in agreement, could anyone tell me where this said valve is located and if it's an easy/awkward job to replace.
Many thanks in anticipation
Steve
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Maybe.........
Alternatively it could be that the lifters that are holding valves open are 'leaking down' under spring pressure.
Either way it is worth doing a couple of quick oil changes (say 3000 miles each) and adding some 'lifter treatment' to the oil.
Does the oil pressure warning light go out straight away? or does that stay lit for 20 seconds?
If it goes out straight away then not too much to worry about IMO.
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Could be exhaust manifold gasket?
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Already done 1 oil change, along with wynns lifter treatment, and injector cleaner in with the fuel.
the oil pressure light goes out as normal when the engine is started- when either cold or warm.
It's just the noise (and it's cause) which is the problem.
just to satisfy my mechanics curiosity, anyone know where the pressure valve is on this engine?
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If i am not mistaken its on the side of the oil pump just above oil filter, but I might be wrong thou.
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Opposite side to oil filter (on a 2.0 anyway), large hex-head bolt IIRC. Easy enough to get to. I'll try to find a pic in a bit.
For what it's worth, I can't see the oil pump pressure relief valve having anything to do with the noise you're hearing.
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but by staying open, could this valve be allowing the oil to drain from the lifters?
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Although I've only encountered lifter noise on the v engine, the symptoms do sound similar to sticking lifters caused by too few ,or too long between, oil changes, thanks to vauxhall trying to impress fleet managers with longer service intervals.
Usual advice is to try a few quick oil changes, with wynns, to clear out the goop. So it might be worth persevering with another oil change or two at least, ESP if the oil darkens quickly, as it's taking away deposits in the engine. And hopefully flushing out your lifters.
If suspecting oil pressure, it's best to check the oil pressure output with a suitable gauge by removing the oil pressure sensor, fitting the pressure gauge and running the engine to take a reading. Haynes has the correct readings, and then see of the pressure is low when cold and hot.
How long since the oil change, and how many? :)
There is a v engine on here with low oil pressure, and it does rattle. But only when hot, presumably when the oil is thinner. So the opposite of yours.
So maybe persevere with the oil changes and wynns. It's known to work. But ultimately it could just be a duff lifter. While the noise is worrying, if it is a lifter, going by Marks comments on here it's not great deal to worry about, I believe.
It's a futting tick (as opposed to a "tocking" tick) suspect exhaust manifold. They then seal up when hot and go quiet in early stages of failure.
Hth
In answer to your last post. No. :)
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Usually change oil every 6 months, and have done since car was new - have only done 500 miles since the last change about a month ago, so i'll give it a few more miles before changing again.
It's more of a clattering sound than a "futting or tocking tick"
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just to add my tuppence worth, I had a similar problem with my 2.2, i would definately say it sounded like noisy tappets. but it did turn out to be a blow at the exhaust manifold. , once I fitted a new gasket the sound dissapeared. if you try this though please be careful as the front two manifold studs tend to shear... >:(
Brett
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Sounds like manifold/Gasket mine is exactly the same and has been for twelve months or more. Have one or more studs missing including the inserts, noise soon goes as you say once hot so its a case for me anyway of putting up with it. Have posted on the forum before asking if anyone would be willing to Helicoil them for me but sadly no takers. :( :(
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Turns out it IS the exhaust manifold that is causing the problem.
Being re skimmed as we speak :-)
Thx for your help guys :-)