Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: sophos9 on 20 September 2006, 16:16:21

Title: 3.0l Slightly Rough Idle
Post by: sophos9 on 20 September 2006, 16:16:21
Ok, first help post since my transition  :P

I have a strange vibration/rough idle problem which is worse when the car is in Drive or the Climate is on, it is still noticable when in neutral but not as bad.

I have changed plugs and leads (GM parts), new EGR valve (other was leaking), complete seal renewal from plenum, fuel rail and the other black part that sits at between the cylinder heads.

I have check all hoses for vacuum leaks, all pipe and rubber connectors are good.

I have cleaned the IAV but must admit, did not lube it after....

No EMS, car pulls clean all the way to the redline although when going slow, had a flat spot around 50mph and going into top gear (bit annoying)

Any other thoughts on what could cause this?

Cheers!!
Title: Re: 3.0l Slightly Rough Idle
Post by: RonaldMcBurger on 20 September 2006, 17:25:26
Dis Pack
Title: Re: 3.0l Slightly Rough Idle
Post by: tunnie on 20 September 2006, 17:42:50
Welcome sophos9, one thing you will find here is McB is never wrong!  ;)

If he says its the DIS then it will be the DIS Pack

Its located towards the rear of the engine on the passenger side, its best to remove the wiper arms then the scuttle drain to get better access.

Access is very limited to the DIS and 3 out of the 4 8mm nuts are out of sight, you should be able to replace it without removing the plenum. Depends what kind of build you are, i can access the DIS faily easily, but i am a skinny git. If you have a son or daughter you might need to put them to work  ;)

As for a replacement, try a local scrap yard or try "AutoVaux.co.uk" - At retail prices a Vauxhall dealer will be very expensive, if you can get a Trade Club card from someware, this will help as it gets you cheaper than trade prices.
Title: Re: 3.0l Slightly Rough Idle
Post by: sophos9 on 20 September 2006, 19:22:52
That sux, the DIS pack can fail before I sort it then, I presume failure is progressive....

Ronnie can be wrong sometimes, like using pattern rocker cover gaskets, wanting to buy a Mondeo and getting stressed when his Mego kept blowing rockers cover gaskets.... he he  ;D

Just kidding, he knows his stuff for sure!



Title: Re: 3.0l Slightly Rough Idle
Post by: Del Boy on 20 September 2006, 19:28:36
Quote
Dis Pack

I always agree with RMCB but that's cause he is always right  ;D
Title: Re: 3.0l Slightly Rough Idle
Post by: sounds2k on 20 September 2006, 23:02:53
it's called "vicarious learning" ... we learn from Ron's mistakes  ;)

have a look on fleabay for the DIS pack too, might be cheaper than trade club - worth shopping around though.
Title: Re: 3.0l Slightly Rough Idle
Post by: sophos9 on 20 September 2006, 23:16:53
Sounds2k, can you remember all that? Well made me laugh!!  ;D

Cheers for the help all, am not gonna bother at the mo, I'm only being picky!

Will keep an eye on it and see what happens, if it starts to degrade then I will have to lose my knuckles again...  ::)
Title: Re: 3.0l Slightly Rough Idle
Post by: Marks DTM Calib on 21 September 2006, 09:47:26
Did pack....I dont agree, it would be worse when cruising (higher voltage required)

It sounds more of an air leak type symptom...........which could be from anywhere.

Are the breathers nice and clean to?
Title: Re: 3.0l Slightly Rough Idle
Post by: theolodian on 21 September 2006, 10:04:27
Mine is idling at 500 rpm and a bit lumpy in neutral, better in Drive.  Was going to clean breathers and ISV anyway.  If that doesn't do it, then I'll be back for advise.
Title: Re: 3.0l Slightly Rough Idle
Post by: sophos9 on 21 September 2006, 10:24:10
Quote
Did pack....I dont agree, it would be worse when cruising (higher voltage required)

It sounds more of an air leak type symptom...........which could be from anywhere.

Are the breathers nice and clean to?

Hi Mark, thanks for the reply. When cruising there is no problems, car pulls clean. Even at 750rpm there is no vibes or fluctuation.

The breathers I have checked:

The breathers are surpisingly good - the car has an excellent service history!

As for air leak, i have visual checked everything although that does not mean that much. The only suspect pipe which I have taped up is the one that goes from the passenger side intake to throttle body which leads to the IAV and FPR

What is the likelyhood of the IAV playing up a lil?

ALSO... when starting the car up from cold, upon firing (which is quick) it spluters for about 1 second?...
Title: Re: 3.0l Slightly Rough Idle
Post by: RonaldMcBurger on 21 September 2006, 15:54:38
I never said Dis pack was faulty. I just said DIS pack. ;D

Now I am going to say Wiper blades.

There!

If the car is pulling fine at speed and cruises ok, this would indicate more of an idle problem. So, ICV (I know), vacuum pipes, plenum air leak, etc etc. Retrace what you have done and check vacuum pipes are on, not leaking and are in the right place, especially the front multiram etc.

Don't listen to that Mark bloke. He just guessed what I would say about the Dis pack and beat me to it. :-?
Title: Re: 3.0l Slightly Rough Idle
Post by: sophos9 on 21 September 2006, 16:24:43
 ;D Typical Finley, how you doing?

Thanks for that! I have been over everything time and time again, replacing seals and everything! Will replace that bit of pipe and see if that sorts it, if not, I'm guessing IAV...

What is the best 'substance' to soak the IAV in over night to remove all the crud. Will i need to lube anything after?
Title: Re: 3.0l Slightly Rough Idle
Post by: Admin on 21 September 2006, 17:05:48
I don't recommend "soaking" the ICV in anything!  :o

I would recommend using carb cleaner to remove the deposits and then lubricating with a few drops of 3 in 1 oil.

Just make sure the seal between the valve housing (the black rubber ring) and the plenum is good. Even a tiny amount of unmetered air will cause problems.

Title: Re: 3.0l Slightly Rough Idle
Post by: sophos9 on 21 September 2006, 17:54:08
Hey laid, I have even replaced the rubber seal/jacket!! Thats how far I have gone trying to resolve this problem!!

Guess next steps are to change that pipe and clean the IAV out proper....

or

leave it till it gets proper bad!
Title: Re: 3.0l Slightly Rough Idle
Post by: B52 on 21 September 2006, 18:26:12
not sure but I had something similar on my last car - it was 'hunting' on idle (revving up slightly and then nearly stalling). anything like this? it was an air intake leak.
Title: Re: 3.0l Slightly Rough Idle
Post by: TheBoy on 21 September 2006, 19:51:01
Quote
not sure but I had something similar on my last car - it was 'hunting' on idle (revving up slightly and then nearly stalling). anything like this? it was an air intake leak.
Classic air leak sympton...  ...icv can cause similar, but tends to stabilise after a few secs in my experience, whereas air leak will hunt indifinately
Title: Re: 3.0l Slightly Rough Idle
Post by: Martin_1962 on 22 September 2006, 10:57:23
Check for splits in the pipes at the back of the plenum
Title: Re: 3.0l Slightly Rough Idle
Post by: sophos9 on 22 September 2006, 18:26:23
Thanks for the replies...

The pipes at the back of the plenum are all good, replaced them about 6 months ago.

The car does not 'hunt' to the degree you described, at a guess it hunts by about 50rpm and never stalls!!
Title: Re: 3.0l Slightly Rough Idle
Post by: theolodian on 22 September 2006, 20:33:47
I took a slightly closer look at mine and the hose is partially off at the back of the MAF.  I'll deal with that and take a closer look as I do the cambelt and cam cover gaskets.
Title: Re: 3.0l Slightly Rough Idle
Post by: Kev on 22 September 2006, 20:42:03
Quote
I took a slightly closer look at mine and the hose is partially off at the back of the MAF.  I'll deal with that and take a closer look as I do the cambelt and cam cover gaskets.
You're gonna be a busy boy then, good luck.  [smiley=thumbsup.gif]
Title: Re: 3.0l Slightly Rough Idle
Post by: theolodian on 22 September 2006, 21:14:14
Eh, I'm thinking of doing the cambelt tomorrow and the cam cover gaskets next Saturday.  A little extra work, but less stress.