Erratic idle

[Radar]

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

[hotel21]

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......      

[hotel21]

As an afterthought - and not wanting to start the alarm bells too early - when was the cambelt and tensioner kit last done??    

[Radar]

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

[Entwood]

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

[hotel21]

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.   

[TheBoy]

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?

[noel]

[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

[feeutfo]

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. 

[TheBoy]

600 rpm is normal for idle speed mine idles at 500 rpm when warmed up

DBW engines should all idle at 600rpm, AC on or off.

[feeutfo]

Although clean and lite lube the icv wont hurt any.

How many miles on current cam belt kit? Just to sure...?

[feeutfo]

600 rpm is normal for idle speed mine idles at 500 rpm when warmed up

DBW engines should all idle at 600rpm, AC on or off.

yes i thought 2.6. But showing 2.5....

[TheBoy]

600 rpm is normal for idle speed mine idles at 500 rpm when warmed up

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

[Radar]

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

[feeutfo]

600 rpm is normal for idle speed mine idles at 500 rpm when warmed up

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