Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Radar on 12 December 2011, 19:36:17
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Had a wierd one today - drove the car 2 miles this morning after it being parked up for the weekend - all ok.
Dropped the little one off at nursery and then when i started the car it was stuttering as if it was going to stall - then whilst driving in slow moving traffic at revs under 1500rpm the stuttering noise continued coupled with a screaching noise plus a sound similar to a rusty pulley going round. Above 1500 rpm there was no problem.
Anyone have any ideas what could have caused this. (I wondered if some water had got onto the aux. belt or some grit?)
I drove the car at lunchtime and this evening and there was no repeat of the stuttering or rusty pulley sound.
Thanks
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Rev change/hunting at idle is generally the Idle Air Control valve but the screeching points to something else.
Have a looksee for replacing the aux belt. Sounds like the tensioner pulley may be going west...... ;) :y
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As an afterthought - and not wanting to start the alarm bells too early - when was the cambelt and tensioner kit last done?? :o :o
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Cambelt and tensioners done in may 2009.
Aux belt and pulley replaced one month ago.
I've always thought the car idles at too low revs. approx. 600rpm and feels like its hunting but this instance was far more pronounced.
Like the santa smileys btw
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Other sources would be any of the pulleys ... the aircon pulley can cause a large drag if it is slipping, the screech is either a pulley bearing or the belt slipping on a non-turning pulley at a guess, either would cause an increased load on the engine causing low/hunting rpm
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Would suggest that you need to confirm whether its on the aux belt side of things or the timing setup. That means, really, being able to replicate the noise if possible and then stop the engine and remove the aux belt completely, restart and replicate.
I know thats the ideal world and not the real one but hopefully you can see where I'm coming from/heading. :y
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Cambelt and tensioners done in may 2009.
Aux belt and pulley replaced one month ago.
I've always thought the car idles at too low revs. approx. 600rpm and feels like its hunting but this instance was far more pronounced.
Like the santa smileys btw
600rpm is perfect for A/C on, should drop to 450rpm with AC off. V6 doesn't need to idle as high as a 4 cylinder.
Keep a close eye on it, the noise is worrying.
What electrical bits did you have on, wondering if 2 faults, a duff idle, and a belt slipping due to alternator working very hard?
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[quote
I've always thought the car idles at too low revs. approx. 600rpm
600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
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Other sources would be any of the pulleys ... the aircon pulley can cause a large drag if it is slipping, the screech is either a pulley bearing or the belt slipping on a non-turning pulley at a guess, either would cause an increased load on the engine causing low/hunting rpm
...beat me to it. Imo wip the aux bely off, after noting the routing with camera phone if needed, and spin the various puleys where possible, see if anything is seized or showing play. Hopefully not an issue with ac pump/clutch.
Agree re idle speed. Normal. :)
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
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Although clean and lite lube the icv wont hurt any.
How many miles on current cam belt kit? Just to sure...?
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
yes i thought 2.6. But showing 2.5....
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
yes i thought 2.6. But showing 2.5....
Radar's is 2.5, Noel's is 2.6 ;)
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Cambelt and tensioners done in may 2009.
Aux belt and pulley replaced one month ago.
I've always thought the car idles at too low revs. approx. 600rpm and feels like its hunting but this instance was far more pronounced.
Like the santa smileys btw
600rpm is perfect for A/C on, should drop to 450rpm with AC off. V6 doesn't need to idle as high as a 4 cylinder.
Keep a close eye on it, the noise is worrying.
What electrical bits did you have on, wondering if 2 faults, a duff idle, and a belt slipping due to alternator working very hard?
There were no electrical bits on at the time. When i first started her up the speedo/rev needles twitched which sometimes happens when not used for a few days. I drove 2 miles with heaters on - no noise. Did my drop off then restarted with no electrical bits on and this was when it started.
Will take the belt off and spin the pulleys when i get a chance. Strange it has not repeated itself again
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
yes i thought 2.6. But showing 2.5....
Radar's is 2.5, Noel's is 2.6 ;)
oh....ffs ;D :y
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
yes i thought 2.6. But showing 2.5....
Radar's is 2.5, Noel's is 2.6 ;)
it shows 500 rpm + needle width near enough for me ;)
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Although clean and lite lube the icv wont hurt any.
How many miles on current cam belt kit? Just to sure...?
About 8000 miles (May 2009) - Gates Kit
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
yes i thought 2.6. But showing 2.5....
Radar's is 2.5, Noel's is 2.6 ;)
it shows 500 rpm + needle width near enough for me ;)
Yeah, as long as its stable and approx correct, near enough :y
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Although clean and lite lube the icv wont hurt any.
How many miles on current cam belt kit? Just to sure...?
About 8000 miles (May 2009) - Gates Kit
Thats fine then. :)
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Thanks guys - will see if it repeats itself again and will try at the weekend to spin the pulleys / clean icv
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Although clean and lite lube the icv wont hurt any.
How many miles on current cam belt kit? Just to sure...?
About 8000 miles (May 2009) - Gates Kit
Thats fine then. :)
Whoa there :o
The shrieking is a warning that something is amiss. Just because most cambelt followers last 40k+ miles without problem isn't a guarantee that this one one of these three isn't suffering premature failure.
If it was my car I would spend a morning checking the usual (& not so usual) suspects
Aux belt off & check that tensioner, a/c compressor, alternator, water pump and power steering pump all turn smoothly.
Sticky starter motor?
Radiator fan?, heater fan? Self levelling compressor?
If nothing obvious I would go a step further and remove the cambelt to check that the tensioners all still turn smoothly (having attached the cam/crank locking kit first of course........)
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600 rpm is normal for idle speed mine idles at 500 rpm when warmed up :y
DBW engines should all idle at 600rpm, AC on or off.
Could someone please tell mine that. 450-700 ::)
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Must confess i haven't got a chance to wip off aux belt / clean icv. Have driven approx. 300 miles with no probs.. until today.
Started her up after 2 days non use and left idling for 3 mins - all ok. Switched off and restarted after 5 mins. and in park no probs., but in drive there was stuttering. Whilst driving she was ok except whenever she changed into the top gear the stuttering came and sounded rough and on one occassion there was a whining bearing type whine (even the mrs. heard it) I drove 40 miles like this.
On the return journey 40 miles no probs. whatsoever.
I will get round to cleaning icv valve / pull belt off.
Is the egr valve something you clean also?
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Needs investigating Radar. Bring it round later in the week if you like?
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Thankyou very much Chris. If you let me know what time is convenient for you and I will be there. :y
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UPDATE:
Cleaned and soaked the icv with carb cleaner and lightly oiled - it was a little grubby but not too bad IMO. Some limescale bits came out. There is a flap that moves left to right but when closed it does not fully cover the hole - can anyone tell me is this normal?
Wipped off aux. belt.
Water pump spins fine in one direction but when turning the other a clicking noise is heard (Original water pump still on)
Cranshaft pulley is stiff and i could not get it to move - maybe it was because access was tight but i couldn't shift it.
All other pulleys rotated ok. (Aux. belt and pulley changed about 2 months ago - all orig. vx parts)
If the crankshaft pulley is knackered can it be fixed/regreased or is it replacement time. It looks big so hopefully not too much of a sting/major job!
Any comments appreciated.
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I had that problem- I whipped off the auxilary belt and started the engine-found I could move the water pump pulley side to side. Replaced it and all was ok.
Whilst doing it I checked the alternator pulley. That can make a horrible noise if the bearings in it are gone-mainly caused by the belt being too tight or it being renewed.
Just a tip.
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UPDATE 2:
Chris Gixer diagnosed a misfire due to oil in the plug wells - left side mainly with water in right hand plug wells. He kindly replaced the cam cover gaskets and put on new ht leads as one was completely buggered. Water was dripping onto right hand side bank at the back so sealed up the scuttle drain and fingers crossed.
On the drive home it runs smoother - so big thanks to chris for all his time and efforts :y :y
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Couldn't find anything to account for the screech during test drives, or by checking pulleys, all span free and smooth, ac clutch working fine. Apart from the miss it was good as gold.
Water was peshing in from the scuttle when we tested with a hose though. Sealed with mastic, hopefully.