Irregular idle revs

[Frenchi93]

Problem guys, I've got a 2010 Fabia Vrs and yesterday as I came to a stop after a while of driving my car so it was fully warmed up. The idle revs were going up and down for no reason as I was not touching the accelerator, it goes from normal idle around 750? To around 1100 sometimes! I read on the forum about an Octavia doing the same and someone said the PCV valve? The engine management light is on but I'm in Amsterdam for the weekend it happened just before i was going home to go to the airport so not had time to check what it could be.

Thanks Ryan

[Ootohere]

How old, how many miles, was and is it running 98 or higher Ron petrol and have the spark plugs been changed or checked?

[FabMonte]

make sure no inlet air leak , check all hoses are connected correctly.

inlet air leaks can give idling rev. change.

go for simple stuff first.

..best of luck.

[Ootohere]

750rpm is just a little low. And as the cooling fans or heater or any load goes on the battery the RPM needs to rise and the alternator is charging the battery. If the A/C is on auto it will also have the RPM rising and falling.

Edited 7 December, 2014 by goneoffSKi

[muckingfuppet]

Sounds more like a hunting idle rather than something caused by ancilliaries, my CAV engine was doing this when I picked it up from the garage on Wednesday. seems to have settled down and stopped now though...

[Ootohere]

muckingfuppet,

 sorry missed the story, what do you have now then in your Polo,

a new engine, updated ECU, new CAT, what else?

 

Extended Warranty?

[muckingfuppet]

muckingfuppet,

 sorry missed the story, what do you have now then in your Polo,

a new engine, updated ECU, new CAT, what else?

 

Extended Warranty?

 

 

Just a new block and head, both CAV spec. Intake manifold forward and exhaust manifold back, plus ancilliaries were transferred from the old engine to the new. I questioned them about the cat, and asked about the turbo as well seeing as that would have had bits of spark plug and piston flying through it. They couldn't answer, but I took the car off them anyway. I had been away again for 6 weeks, and I had asked them to do a couple of other bits while they had it (MoT amongst others), which they hadn't apparently managed to fit in, so I took the car to a local garage and gave them the money instead. Still pushing the route with VW Finance to get rid of the damn thing at this stage, I want nothing more to do with it or VW. As for warranty, I asked this also, apparently because it was an approved warranty repair, the new components are only covered for a year. Financial Ombudsman and Trading Standards have been involved now, just waiting on the paperwork to come through from the FO to get it all started in earnest with them.

[Ootohere]

sorry to the OP for the OT.

That must be VW Parts if it is a New Base Engine so should be 2 years Warranty on them if bought and paid for by a Warranty Underwriter,

and not by VW's Insurance / Warranty.