Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: MutantCav on 13 January 2008, 18:37:25
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Ok guys, picked up my nice cheap 1999 Omega 2.5 v6 Estate today, everything is as it should be except for one thing...the way the engine runs...ok, the symptoms are as follows as far as I can see...
engine idles ok although exhaust sounds slightly rumbly from the rear but its new...there is a slight hiss sound from near the passenger footwell but overall the engine idles pretty nice...oh and there is a slight and strange noise coming from the plenum which I dont think I have heard on any of my previous cars before.
Problem occurs when you press the accelerator, even gently it sounds like its running rough suddenly...but accelerates pretty well (better at speed, not so well at pull away but then I did have a lot of extra weight so hard to judge) and the hiss goes away. Its just done 180 miles towing another car so and the engine temp was fine, 93-95 degrees, returned 20mpg average despite a ton of extra car on the back and pulled at 60 sounding on the whole pretty good so overall seeming like its nothing major.
My thoughts are its EGR valve or maybe a slight air leak etc, any ideas?
P.S. Havent checked for oil in the plugs yet as its dark! :)
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I would be methodical
A) Check for obvious air leaks
B) Check for DTCs
C) Check for oil in plug wells and condition of plugs/leads
What's the service history?
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What are DTC's?? Has full service history but engine was changed 40k ago (apparently) and its maybe slightly questionable...
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Sorry,
Fault codes.
When was the cambelt kit last done mate?
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Havent had a chance to check for fault codes...been a long day lol will do tomorrow...but assuming its true, brand new engine 40k ago so belt would have been done then.
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at 40k its due again chris every 40k or 4 years !!! :y
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Indeed, and there is a cambelt party coming up which I may well attend :) But I wouldnt have thought this was anything to do with the issues I'm experiencing?
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Indeed, and there is a cambelt party coming up which I may well attend :) But I wouldnt have thought this was anything to do with the issues I'm experiencing?
It would be if the valve timing is out by a few degrees ;)
Although it's not the first place I'd look.
Never rule anything out, there are lots of unknowns on a 2nd hand car...
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I'm wondering what the hissing noise is, its not overly loud, just like a speaker hiss if you didnt have a channel on the radio...but only the passenger side footwell and only when the accelerator isnt pressed...but then the grumbling from the engine only happens when the accelerator is pressed...not sure if an air leak would be audible all the time?? Would no doubt cause a rough engine on acceleration though? Idles at 500rpm though no problem
Incidentally where should the estate exhaust end, before the back bumper or under it and out the back?
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Hiss will most likely be the Secondary Air Injector and is quite normal :)
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May be good idea to check air leak around plenum..
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Hiss from passenger footwell suggests the vacuum pipe come off.
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Where is the vaccuum pipe? and would this potentially cause poor running on acceleration??
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Where is the vaccuum pipe? and would this potentially cause poor running on acceleration??
There are various actuators for heating system behind the glovebox.
Vac leaks, like air leaks, can cause poor idling, not sure about your symptoms though :-/
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So whip out glovebox and see if you can see where hiss is coming from?? Well that could be one issue down even if its not related to the engine problems :)
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Check in the pollen filter area...
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Around where the HBV is?? To see if blocked?? Havent done that before but worth checking whether the fault or not lol :)
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So whip out glovebox and see if you can see where hiss is coming from?? Well that could be one issue down even if its not related to the engine problems :)
just get your head in foot well chris and have a good look around !! :y
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The lock on the glovebox is missing anyway so need to swap it over...but now its been said hissing is definitely from behind glovebox...
Just had a drive around without a ton of car being trailored and symptoms are slightly different...basically its just running a bit lumpy, improves at higher revs...I think the extra weight was making the issue seem worse
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to eliminate pronblems one by one,
first change o-rings under the plenum.
change the gasket from the metal arm from EGR to plenum..
check The ICV to plenum inlet gasket..
And block the EGR with a metal sheet..And dont unplug it..
Now check the car ..if problem persists check the ecotec-bit o-rings..
I had similiar problem..When I changed the o-rings the hissing noise gone..
Lastly clean the throtlle valves ..
ps: also injector o rings can be changed but is a long task..
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Ok, just checked the service history...I will go by what it says rather than any supposed to have happened hearsay...130k on the clock with FSH, all but the last one done by Vauxhall at 5k 23k 35k 64k and 79k when the cambelt was changed...then a local garage full service stamped at 114k...so cambelt tensioners are within risk period after 51k but last full service was 16k ago :) No idea how long its been running rough though!
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Ok, just checked the service history...I will go by what it says rather than any supposed to have happened hearsay...130k on the clock with FSH, all but the last one done by Vauxhall at 5k 23k 35k 64k and 79k when the cambelt was changed...then a local garage full service stamped at 114k...so cambelt tensioners are within risk period after 51k but last full service was 16k ago :) No idea how long its been running rough though!
Ah, that belt needs doing pretty pronto then...
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Cambelt and tensioners is no 1 priority..
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Cambelt and tensioners is no 1 priority..
If I had paid full money for it then I would agree...as I paid peanuts for it the priority is to get it running properly :) There is a cambelt party in the midlands though so I'm seriously looking at going to that :)
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well, you know :)
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If the worst happened then I could get the money back that I paid out from parts in about 2-3 days...but obviously worth doing anyway to keep the car sound as its pretty good overall...
O rings under the plenum...will give that a go first as there is a distincly strange noise coming from under there...and it does sound like its specifically from the plenum itself :)