Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: megaomega123 on 16 July 2007, 16:29:24

Title: REALLY rough idle
Post by: megaomega123 on 16 July 2007, 16:29:24
Car is idling bang on 500, needle does not move at all. When sitting in the car it rocks from side to side and knocks a bit at the back. The engine sounds to be struggling to keep going. Big blow in exhaust just before back box.

Would the blow alone be causing this? I have videos if anybody so desires.
Title: Re: REALLY rough idle
Post by: Markjay on 16 July 2007, 16:31:47
Quote
...Big blow in exhaust just before back box.

Would the blow alone be causing this?...

Personally I think the answer is yes.

Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 17:33:53
Exhaust is now done, so it is new from cat back. The idle has remained the same. The car rocks from side to side when idling and sounds rough but the rev counter sits still at 500rpm.

This has started happening since doing the cam cover gaskets. Is it possible I have done something wrong. Also as added info the aux belt tensioner is in urgent need of change. ( cambelt, water pump and aux tensioner being don on Tuesday).

Is there anything else that could be causing this issue. Videos of the idling below.

http://s55.photobucket.com/albums/g135/phate123/?action=view&current=50bee528.flv

http://s55.photobucket.com/albums/g135/phate123/?action=view&current=4729a4f4.flv  
Title: Re: REALLY rough idle
Post by: Mike Collins on 17 July 2007, 17:50:11
What is that orange light? if it's EML check for error codes.
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 17:53:10
Quote
What is that orange light? if it's EML check for error codes.

Thats handbrake, just looks orange on my sh*t camera
Title: Re: REALLY rough idle
Post by: geoff on 17 July 2007, 18:24:42
have you tried cleaning idle control valve and breather pipes ,this may cause this :y :y :y
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 18:30:27
Quote
have you tried cleaning idle control valve and breather pipes ,this may cause this :y :y :y

All done during camcover gasket m8 icv cleaned to within an inch of it's life.
Title: Re: REALLY rough idle
Post by: geoff on 17 July 2007, 18:34:12
have you checked to see if timming is set right all so and when was your belt last done,needs to be done every 40 thousand miles or every four years which ever comes first,plus tensioners to be changed with belt :y :y :y
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 18:37:41
Quote
have you checked to see if timming is set right all so and when was your belt last done,needs to be done every 40 thousand miles or every four years which ever comes first,plus tensioners to be changed with belt :y :y :y

It is being done on Tuesday (can't come soon enough). I just need to know the symptoms of timing being out or belt and tensioner just about to let go.
Title: Re: REALLY rough idle
Post by: Mike Collins on 17 July 2007, 18:40:44
Has the EGR been blanked off, that helped on mine.
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 18:42:48
It hasn't. Not sure how to do this. Is it a good idea to mask a problem that could be something more serious?
Title: Re: REALLY rough idle
Post by: geoff on 17 July 2007, 18:46:40
i would try belt and tensioners first ,if it is retarded and timming is out can really run rough :y :y :y
Title: Re: REALLY rough idle
Post by: Markie on 17 July 2007, 19:26:27
icv back in properly? checked for air leaks? lets do the basics first....

its unlikley to be timing if its happend since cam covers and only since then,,..
Title: Re: REALLY rough idle
Post by: Mike Collins on 17 July 2007, 19:32:36
I doubt that blanking the EGR would mask anything other than a leaking EGR. It has been disturbed during the cam cover change I think. Easy to do, thin sheet metal under the valve, should be a descripition on here.
Don't unplug the connector though, that will generate an error.
Title: Re: REALLY rough idle
Post by: JamesV6CDX on 17 July 2007, 19:38:07
I think this is going off track a bit.

A blowing backbox wouldn't cause it to run unevenly. My V6 doesn't even HAVE a backbox, and albeit loud, it goes like sh*t off a shovel ;D

The way the OP describes the car as "rocking from side to side" is telling me that it's misfiring.

First job is to check out all the plugs and leads. Check they're in securely, and in the right place!!

I suspect after the camcover change, 2 x plug leads have been crossed. Usually 4 and 6 on the 2-4-6 (passenger) bank... near the bulkhead.

I'll put money on it  ;)
Title: Re: REALLY rough idle
Post by: Markie on 17 July 2007, 19:39:35
Quote
I think this is going off track a bit.

A blowing backbox wouldn't cause it to run unevenly. My V6 doesn't even HAVE a backbox, and albeit loud, it goes like sh*t off a shovel ;D

The way the OP describes the car as "rocking from side to side" is telling me that it's misfiring.

First job is to check out all the plugs and leads. Check they're in securely, and in the right place!!

I suspect after the camcover change, 2 x plug leads have been crossed. Usually 4 and 6 on the 2-4-6 (passenger) bank... near the bulkhead.

I'll put money on it  ;)

which would also make it very very lumpy on revving....


so is it phate321?
Title: Re: REALLY rough idle
Post by: JamesV6CDX on 17 July 2007, 19:43:44
The other possibility, is a biiig air leak in the plenum area. Is the servo hose back in on the passenger side... and is the bit of rubber on the bottom underside of the "ecotec" breather assembly on the top of the plenum..

Are the 4 x pipes connected to the back of it?

Something simple here...
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 19:55:15
I've gone through all the pipes and connectors and all seems well. My first thought was plugs the wrong way round but they are ok. It ONLY happens on idle and drives gr8 until idling. You would think an air leak or plug and lead problem would show right through the range.
After doing gaskets, on 1st start, it started loud and rough and the aux belt began to smoke from the pulley below the tensioner, bottom left from face on. I switched off, left for a minute and restarted. I restarted 3 times then let it warm, thats when this problem started.

The only thing I have doubt about, after the work, is the o-rings between plenum and inlet bridge. I do not recall removing o-rings from under the 4 plenum bolts so did not replace any here. I would presume that the orange gasket are all the should be between plenum and inlet bridge.  
 :'( :'( :'(
Title: Re: REALLY rough idle
Post by: JamesV6CDX on 17 July 2007, 19:57:39
Ok -

Plugs wrong way will misfire through the range, so can rule that out.

Air leak however, will only run rough at idle (in my own experience) - and it was the seal on the bottom of the ecotec box.

A plenum O ring missing, will also definately cause this behaviour..
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 20:00:56
I know for a fact that the rubber under the breather box is distorted and ill fitting. Should there be o-rings under the plenum bolts?
Title: Re: REALLY rough idle
Post by: TheBoy on 17 July 2007, 20:04:07
Quote
I know for a fact that the rubber under the breather box is distorted and ill fitting. Should there be o-rings under the plenum bolts?
If the seal is rubbish between Ecotec plastic bit and plenum, that will affect idle.  No o rings under plenum bolts.
Title: Re: REALLY rough idle
Post by: JamesV6CDX on 17 July 2007, 20:04:36
Quote
I know for a fact that the rubber under the breather box is distorted and ill fitting.

Well, when that was the case on mine, idle was awful, just like you're seeing.

As a temp fix to get me home, I used the seam of a latex glove around it to get me home... and it sealed it really well!!! But I then replaced it properly.




Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 20:34:59
Just had a closer inspection. Most of the noise is coming from the passenger side. In particular top right pulley face on, water pump? Bottom right pulley not moving, but i think thats air con.
The lumpiness continues to about 2000rpm.
Title: Re: REALLY rough idle
Post by: TheBoy on 17 July 2007, 20:44:22
Quote
Just had a closer inspection. Most of the noise is coming from the passenger side. In particular top right pulley face on, water pump? Bottom right pulley not moving, but i think thats air con.
The lumpiness continues to about 2000rpm.
power steering?
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 20:46:17
Quote
Quote
Just had a closer inspection. Most of the noise is coming from the passenger side. In particular top right pulley face on, water pump? Bottom right pulley not moving, but i think thats air con.
The lumpiness continues to about 2000rpm.
power steering?

Power steering working as normal.
Title: Re: REALLY rough idle
Post by: TheBoy on 17 July 2007, 20:47:44
Quote
Quote
Quote
Just had a closer inspection. Most of the noise is coming from the passenger side. In particular top right pulley face on, water pump? Bottom right pulley not moving, but i think thats air con.
The lumpiness continues to about 2000rpm.
power steering?

Power steering working as normal.
Thats the top right pulley.
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 20:51:55
 :-[ lol

Well that can't be the cause then just a symptom.
Title: Re: REALLY rough idle
Post by: megaomega123 on 17 July 2007, 20:52:47
Everything is shaking and shuddering, like it's gonna break into parts.
Title: Re: REALLY rough idle
Post by: JamesV6CDX on 17 July 2007, 23:08:21
Get that plenum off and find the missing O ring!! they often come away attached to the plenum, and don't remain in the groves on the inlet. Chances are you may have dropped/lost one...