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[treeman]

Hi Everyone!
I hope some of you can help me with you expertise and experience

I am new to this forum and fairly new to Omega ownership.  I bought an 85000 mile, 1998, V6 Omega Elite about a month and a half ago.  It has been no trouble for the first 2000 odd miles apart from a bit of an oil leak. 
 
Two days ago it suddenly stopped being so reliable.   

On restarting after a brief stop, the engine immediately felt wrong.  It felt lumpy and down on power. Not so much a misfire, more like not running on all cylinders, however there was no engine light flashing a warning at me. 
I spent the evening trawling the Internet and thanks to this and another site found a lot of useful information. 

Checked my plugs and leads the next day and found the source of my oil leak.  The passenger side rocker cover was the culprit.  My plugs and leads have been marinated in oil for I don’t know how long. I sucked the oil out with a syringe and carefully cleaned each plug and lead. I didn’t see anything to make me recoil in horror, the plugs all appeared to be in reasonable condition and didn’t look old. I put everything back together and hoped for some improvement.  However a test drive revealed the same as before.

There are no clouds of smoke or loud mechanical noises. The engine is just way down on power right through the rev range and sounds lumpy, but still nothing from the engine management light.
 
I have ordered the parts to fix the oil leak, but I’m procrastinating about how to proceed after that.  While its in bits, I may as well replace the plugs (though the old ones look fine) and HT leads.  But I am suspicious of the coil pack too.
 
Wouldn’t coil failure cause the engine warning light to illuminate?   Would it be better to get a garage to run a diagnostic test, before I replace perfectly good components?  As the car is not worth very much, just taking it to a garage to fix is out of the question.  Anyway im quite capable of replacing a faulty part if I can find which one. 

Any thoughts and advice would be most welcome.

[geoffr70]

Hi.

I'm no expert but it sounds like you need to clean your breathers also. See here:

http://www.omegaowners.com/forum/index.php?topic=90653.0

Then it'll stop the pressure blowing the cam cover gaskets again. There is a guide on doing the cam gaskets. The passenger side is alot more awkward due to having to remove the cable tray. I've only used genuine cam gaskets, but people on here have used cheap pattern parts which don't last long. You can PM Andyc on here to get bits for trade prices. Worked out to £65 ish when i got mine.

Instead of getting garage to read codes you can do it yourself buy the paperclip test. See the maintenance guide.

Don't know about coil/dis packs and all that, but that might be ok. The oil might've fried your HT leads though.
HTH

[geoffr70]

Blocked breathers causing cam gasket failure is common on here. I change my oil and clean the breathers every 3k to stop it. It's cheaper and easier!

[Zippy2012]

hi on my old 2.5 v6 cdx i had a similar issue no lights nothing.... & yes my coilpack had a lovely split down the middle but it is an absolute bastard to get to unless u have the fingers hands & arms of a small child but adult strenth! as you have to remove alot of gear platenam chamber fuel rails etc & replace loads of gaskets too real headache!!

but the coilpack only played up when engine was hot...
but faulty leads can give you an issue from cold & again no eml...
Have you checked plugs for slight cracks but again they playup normally when warm/hot??

i had a 2.0 16v vectra with a major oil in to plug area leak & that yes shorted out the plugs cracked 1 & fryed a lead...

yours maybe fine but easy way 2 check a lead/coilpack issue is pull each lead off while running if you can get to them??
engine should run rough when each lead removed & back to normal when refitted...
if engine runs the same on removing a certain lead could be something on that specific lead/plug etc if that fails then ask if anybody on here has a tech 2 in your area cheeper than a £90 diagnostic check mate 

[joff]

Hi Treeman and welcome to the forum. Do you have a 2.5 or 3.0 V6? you may need the the help of the parts members on her there are a few who may have the coil pack and leads you need at a very good price (look in the parts section) send them a PM with your needs. It would be better to put a known good set of leads and plugs in and a good coil pack. you will need to use Vauxhall cam cover gaskets or you will be doing the job again in a very short time. Clean out the breathers and keep them clean and do an oil change every 4-6k to keep her clean inside and you will be fine. Oil and filters can be got from Vauxhall dealers and very good price with a trade card which you can get from ABS for £20 which you save times over on your first 20lts of oil. Again welcome to the forum

[chrisdb]

Hi there

You should replace the spark plugs first. The oil on the plugs may have caused the ceramic to overheat and crack, and therefore the plugs could be shorting through the crack. If that doesn't work I'd check the leads next - oil may have damaged these too with similar results.

I've always found that if it sounds like it's not running on some cylinders then it isn't. The most usua' cause I've found for this is when the spark is not igniting in the cylinder head.

Hope that helps.

[Lazydocker]

Hi Treeman and welcome to the forum,

You have, as you thought, found the cause of your problem

An HT fault rarely illuminates the EML on pre and mini-facelifts. As advised, do the paper clip test to be sure there is nothing lurking.

As for how to proceed. I would sort the cam cover gasket(s) (there's a very good guide in the maintenance section), clean the breathers thoroughly (and then change the oil and filter for good measure ) and replace the plugs. If the fault is still there then the leads are the next step unless you can see visible damage to the coil pack. After that it's the coil pack. All this (plugs onwards) assumes that there are no hidden fault codes

The V6 Omega has an unfair reputation of being expensive to maintain. I don't think this is particularly true if you are capable of DIY maintenance and keep on top of it

If you are stuck, there are some very competent members who are willing to travel and help out for a lot less than a garage would charge

Finally, and I'm sure you're aware of it, check the cam belt history. 4 Years or 40k miles... Go over this schedule at your own peril

[Zippy2012]

Hi there

You should replace the spark plugs first. The oil on the plugs may have caused the ceramic to overheat and crack, and therefore the plugs could be shorting through the crack. If that doesn't work I'd check the leads next - oil may have damaged these too with similar results.

I've always found that if it sounds like it's not running on some cylinders then it isn't. The most usua' cause I've found for this is when the spark is not igniting in the cylinder head.

Hope that helps.

i would 2nd that as its happened to me on the vectra with the oil making plugs overheat & crack

Oh DONT Buy plugs from halfords as they only come in a 4pack & u need 6 so you will pay roughly £40+ just for some good bosch plugs...
ummm i may ask that question in a topic "what plugs are best for a V6"....

Defo use the oof parts guy he can get parts cheeper than most places 

[omega3000]

But I am suspicious of the coil pack too.
   

I was as well.





 I have very similar current problems to what you have described , no warning lights came on while driving but the car felt like it was down on 1 or 2 cylinders . Found the coil pack above had tried to shed its skin 



HTH 

[treeman]

Hi Everone!
 
Thanks for all the replies to my post!

More or less confirm everything I had found from my research of older threads. Plus given me a couple of things to try.

I have ordered Rocker gaskets and seals and a set of Bosch super 4 plugs (£27 for 6).   I’m looking at a set of 8mm silicone HT leads for £45. There appear to be two different types of coil pack listed for the X25XE 2.5 (Pt No: 90541062 & 90511450) one is more expensive than the other for some reason.  Will have to see what is fitted to mine before I will know which one to get (if the plugs and leads don’t sort the problem).   I’ve ordered a Haynes manual as well.

I will let you know how I get on and thanks again for the advice. 

[Zippy2012]

Hi Everone!
 
Thanks for all the replies to my post!

More or less confirm everything I had found from my research of older threads. Plus given me a couple of things to try.

I have ordered Rocker gaskets and seals and a set of Bosch super 4 plugs (£27 for 6).   I’m looking at a set of 8mm silicone HT leads for £45. There appear to be two different types of coil pack listed for the X25XE 2.5 (Pt No: 90541062 & 90511450) one is more expensive than the other for some reason.  Will have to see what is fitted to mine before I will know which one to get (if the plugs and leads don’t sort the problem).   I’ve ordered a Haynes manual as well.

I will let you know how I get on and thanks again for the advice. 

i would pm andyC with your reg & vin to comfurm the coilpack from memory i think the coilpacks maybe torqs style bolts but you calnt see them if i rem?? an old mirror maybe handy for doing this... the rocker gaskets can be a nightmare if incorectly packed by supplyer all twisted some people would recomend dry fitting others rtv sealer but im sure somone may say what is best to use?

but do check that your rocker covers arnt buckled because i had to do 1 bank on mine 3times to stop it leaking & was a warped rocker to blame!!
your mrs will prob kill u if she sees this but placing them against a window pain is a good way of checking they are level but make sure they are clean 1st a good tin of brake cleaner works very well! you dont want black oil on your window glass!
carb cleaner to clean the throttle body, platinum chamber egr etc while you have it all stripped down an extra 20mins worth of cleaning the other parts you strip down will also give you better mpg & smoother running saving time later,

but before removing the rocker covers spray the brake/carb cleaner on the oil thats been running down block onto manifolds & wipe off with a old towel works best but dont spray on camshafts or you will degrease/oil the cams & can damage them on restarting & contaminate ur engine oil too but to be honest ide change the oil at same time to remove any debris from rocker cover removal, inc filter hope this helps mate 

[albitz]

Follow this guide.You wont go wrong.
http://www.omegaowners.com/forum/index.php?topic=90542.0

[omega3000]

Hi Everone!
 
Thanks for all the replies to my post!

More or less confirm everything I had found from my research of older threads. Plus given me a couple of things to try.

I have ordered Rocker gaskets and seals and a set of Bosch super 4 plugs (£27 for 6).   I’m looking at a set of 8mm silicone HT leads for £45. There appear to be two different types of coil pack listed for the X25XE 2.5 (Pt No: 90541062 & 90511450) one is more expensive than the other for some reason.  Will have to see what is fitted to mine before I will know which one to get (if the plugs and leads don’t sort the problem).   I’ve ordered a Haynes manual as well.

I will let you know how I get on and thanks again for the advice. 

Thats right there are 2 different connections for the coil pack , yours maybe the cheaper one but mine was the oval connection which the dearest of the 2  I was quoted £40 for leads so seems about right , someone else could confirm if there is a cheaper set available ...vx original HTs i think you would be looking at silly prices 

[Elite Pete]

Make sure the cam cover gaskets you buy are genuine from a Vauxhall dealer or you will be doing the same job again very soon and if your dis pack is Kaput, if you replace it the same time as going the cam cover gaskets its a doddle

[smokingomega]

Hi.
Believe it or not about ten years ago I had a similar problem with a company car where I worked. It ended up being the timing belt idler that had snapped the plastic around it making it slightly smaller and loosening the belt throwing the timing out causing the engine to run lumpy as hell. Me an the other mechanics couldn't believe it still ran and diddnt throw the belt off an goose the engine, like a few of the other company vehicles did.
It's a long shot but if you have tried everything else you never know.