Omega Owners Forum
Chat Area => General Discussion Area => Topic started by: JamesV6CDX on 29 August 2007, 14:25:26
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Hi Guys,
I'm a little confused about the amount of oil I'm putting in my Vectra. The level seems to be dropping quickly, so I'm looking for any ideas on a possible cause.
Observations are as follows:
1) I cannot see ANY leaks. I have rectified every one I have come across, including reseal sump, and new camcover + genuine gaskets. Underneith, and on top - all dry as a bone.
2) Cylinder head has been fully rebuilt by myself very recently, with new valves thoroughly lapped in, and new stem seals. Plus new head gasket. So I don't suspect top end trouble.
3) Upon revving the car, I see dark (but not blue) smoke from the exhaust. This occurs on petrol or LPG just the same. I let the car warm up a bit and it seemed to be the same from warm or cold.
4) No matter how often I change the oil and filter (which is often!) The oil seems to get black very quickly.
5) Without starting an oil thread - I am using FULLY synthetic oil in this car - currently halfrauds 0/40 stuff, as I was able to get a cheap batch.
6) There appeared to be a small amount of oil on plugs 3 and 4 - but I'm almost certain, that it's a bit of leftover oil in the plug wells must have got on them when I Removed the plugs. Otherwise, spark plug colour appears normal considering the mileage.
7) The car has done almost 220,000 miles on the original 1.8l engine! (So I guess it's allowed to use some oil!)
I just did a compression test to see if it picked anything up = readings as follows:
Pot 1 = 218psi
Pot 2 = 225psi
Pot 3 = 250psi
Pot 4 = 250Psi
So all pots seem reasonably healthy.
I do wonder though, if 3 and 4 were slightly higher.. because a bit of oil may have dropped into the pots when I removed plugs? (At least I hope it's as a result of that, rather than it coming up past the rings!)
The MOT is on Friday, so the emissions result should be interesting.
If anyone could shed any light on the oil mystery, then I'd be pleased to hear any views at all.
Cheers :)
James
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Good Luck For Friday's MOT.
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Cheers Ryan... fingers crossed eh!
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looks as if the usual no. 1 pot wear there...
If it ain't leaking, its got to be buring it...
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looks as if the usual no. 1 pot wear there...
If it ain't leaking, its got to be buring it...
My thoughts also, just surprised at the lack of blue smoke if it's really burning it.
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looks as if the usual no. 1 pot wear there...
If it ain't leaking, its got to be buring it...
My thoughts also, just surprised at the lack of blue smoke if it's really burning it.
Has someone followed you when you boot it?
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looks as if the usual no. 1 pot wear there...
If it ain't leaking, its got to be buring it...
My thoughts also, just surprised at the lack of blue smoke if it's really burning it.
Has someone followed you when you boot it?
Is that an offer? I'm not sure Markie's 1.3l Overhead valve Escort could keep up ;D
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That oil is much to thin.....no wonder its using some!
I assume there are no blocked or trapped breathers and that the air filter is all ok?
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That oil is much to thin.....no wonder its using some!
I assume there are no blocked or trapped breathers and that the air filter is all ok?
Really? I stand to be corrected, but I always thought the thinner synthetic oils were OK for the multivalve VX Ecotec engines
I will take your advice though.. shall I drain it all out, in favour of VX 10/40 Semi synth
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With its Space Shuttle Mileage I would guess piston rings are worn slightly.
I have been told a way of checking the piston wear.
Find out what the PSI should be new. Do the checks you just have. then pour alittle oil into the spark plug hole, redo the compression test and if the PSI increase its the piston rings that have worn, the oil gets in to the worn parts of the piston rings and temp blocks any leaks, which inturn increases your compression PSI Thus point towards your worn piston rings
Hope this makes any sense
Craig
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That oil is much to thin.....no wonder its using some!
I assume there are no blocked or trapped breathers and that the air filter is all ok?
Really? I stand to be corrected, but I always thought the thinner synthetic oils were OK for the multivalve VX Ecotec engines
I will take your advice though.. shall I drain it all out, in favour of VX 10/40 Semi synth
the thinner oil will find any leak or wear in engine. Precisely why I do not use it in ZX10 any more.... ...Vx semi in everything now - both Omegas, Rover, ZX10, lawnmower.....
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A drop of oil in the bore will always increase the reading, and - my readings are really not that low, with 220 being the lowest...
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or as i have just read your oil could be to thin lol Doh
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0/40 - it's seeping past rings and seals.
If your selling it too, I'd go and stick 10/40 in it - anyone else who is a would be buyer will use 10/40.
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The oil down the spark plug hole doesn't work at all well
1) A modern engine has the plug in the centre of the cylinder
2) The piston has eyebrows machined in it so any oil dropped in the plug hole tends to sit in these
3) Adding oil increases teh pressure anyway as it lowers the cc.
I would be tempted to use the 15W40 mineral oil from Vx given the high mileage.
The thinner synth does work well on the multivalve engines but, 0W40 is a little thin, probably fine on lower mileage engines.
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Mmmm mineral oil, those were the days!
Will the mineral oil protect it well enough?
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That was exactly my first thought when I read the thread, the oil is way too thin for such a high mileage engine. I was just wondering how many replies there would be before someone mentioned it :).
I wouldn't even use 0w40 in the Omega, and that shows no signs of burning any oil at all. Stick to 10w40 as recommended, or possibly even try 15w50 if that's within the specs (not sure if the hydraulic tappets will like it). I'm currently using Halfords ( :-[ ) fully synth 5w40, but only because I didn't have any VX stuff left when I decided to do the oil change, and the Halfords fully synth was on 2 for 1 offer so worked out cheaper than any of the semi-synth stuff.
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Definately needs some thicker oil.
Can't fault the vaux semi-synth 10w40 at all - used it all the time in the corsa.
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Oil control ring wear and too thin oil.
I would suggest 15/40 possibly even 20/50
On an old car I found that free Vauxhall mineral would burn a lot quicker than Esso mineral. So when my free supply stopped I had to start oil changes again rather than run total loss.
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Won't 20/50 be too thick for the hydraulic lifters, and strain the oil pump?
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Won't 20/50 be too thick for the hydraulic lifters, and strain the oil pump?
Try progressively thicker oils start at 10/40 then go up.
I can't see it straining, but possibly could play up the lifters - you can only try
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15/40 should do - used to use it in the Sunbeam
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Thick oils can cause the lifters to pump up on some engines. Unless the topping up is a real pain I wouldn't necessarily worry too much.
At the risk of prolonging this "oil thread", however, I'm having some difficulty understanding why 0w40 is any worse than 10w40, 20w40, etc. Experience (including my own) says it is, but my understanding of the grading of oils is that the "40" indicates the viscosity is in a certain range at operating temperature (spec'ed at 100 deg. c IIRC). So a 0w40 should have a similar viscosity as a 20w40 at 100 degrees C and should be no more liable to slip through the seals and burn.
The "w" figure ("0", "10", "20"), as I understand it, indicates what viscosity it is equivalent to at lower temperatures, relative to a monograde oil.
In other words, the only difference between a 0w40 and a 20w40 is that, when cold, it pumps easier because it is equivalent to a thinner monograde oil. Oils with a lower winter rating are also usually more resistant to further thinning at higher temperatures (above 100 deg c).
James' engine probably spends most of its' time around 100 degrees C, making the winter rating insignificant, so can anyone explain what I'm missing?
Kevin
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It takes quite a long time to get the engine up to temperature - I would guess easily 5 or 6 miles minimum.
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It takes quite a long time to get the engine up to temperature - I would guess easily 5 or 6 miles minimum.
.. and longer than that to get the oil fully up to temperature, of course. Maybe it's during the warmup phase that most of the oil is lost :-/
Theory and practice just don't seem to meet for me, and it bugs me when that happens. >:(
Kevin
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Personally i would bung vx semi back in it......it always had that in it when i owned it.
I remember telling you James and also mentioned it in a thread that it used 1ltr/2k miles.
Then see what the consumption is like......as a comparision.
Since you have rebuilt the head on it.....i would expect it to be better than 1ltr/2k.
Much worse than that.....then theres summat wrong.....it carnt suddenly start using more oil.
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My tuppence.... ;)
Its an engine with a telephone number mileage as well as goodness knows how many hours ticking over on 'standby' of a cold night with the heater on. Its bound to use oil. Check the Vectra handbook and see what the VX estimated oil consumption is, then double it or so......
Bigger potential prob is why the cylinder comp differences are larger than the recommended 10%. No1 comp down or 3 & 4 increased due to oil presence from plug removal?
I accept what Mark says about pocketed pistons and that the oil will hide there rather than down the bores, but how about this...
Ensure plug holes are clean of old oil. Remove all plugs, retake comps across all four - thats result 'A'. Take compressions with throttle wide open (if cable) or inlet butterfly's removed if FBW.
Put a healthy measure of oil down all 4 bores and, with plugs removed and a suitable absorbent cloth strategically placed and held by your version of Debbie McGee, turn the engine over by hand/spanner then later jag it over on the starter (to avoid possible hydraulic lock) then take readings. This is result 'B'.
Now read and compare comps. If all 4 'A' readings are within 10% of each other, grand.... If one (or two) wildly out, potential problem with indicated cylider(s).
If the wet test comps ('B') are also within 10% but higher, then its simply a tired engine thats had a head job. Oil does a temp job of increasing ring/bore seal long enough to get a set of comps. If no appreciable drop in power output, use 15/50 or 20/50 to reduce costs in 'total loss' oil system.
If you still get 3 & 4 with increased comps in comparison to 1 & 2, then its looking like the head is at fault, despite overhaul. If no difference in 'A' and 'B' then its the head, not the rings.
I know above wet/dry comp tests are like sucking eggs to you James but, to me, its worth a redo to ensure all is OK and its simply tired and has a wee thirst for oil..... :y
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The reason your not seeing any burnt oil smoke out of the exhaust is due to the catalyst collecting it for you. As the oil vapour is different for normal exhaust gases it doesn't pass through the cat as well when its cold, as the cat warms up it slowley starts to burn off the residue oil by which time your engine/piston rings have warmed up and sealed better so any more oil vapour is able to be burnt of by the cat. :)
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Sounds a bit like a thread i started some time ago before i knew better ;D That was which 0#! is best :-X :-X :-X :-X :-X
Lesson learnt :y