Strange Idling

[Guy_H]

Sounds like a leak of some form. Polo GTI's don't have an idle valve, its all done by the throttle body.

[poloplayer]

Wow, I go offline for a bit and come back to find all these replies, makes me proud to own a VW

I appreciate all your suggestions but I don't quite trust myself with the mechanics of the car (quite busy with final exams too) so I booked it in to get checked out by Burwin in the coming weeks. Is it still safe to drive the car now though? I've been driving my gf's swift for the last week or so

[Jmac]

I'm pretty sure lambda sensors are only active when over ~3,000rpm. Even if you disconnect it, it would only display an engine fault light but wont affect its idle, but dont do that because u'll need to have it cleared by VW if u dont have the tools. Polo has two lambda sensors, one under the turbo and another after the cat.

Most cars have a idle air control valve, either its playing up or you have a vacuum leak somewhere. If you have a scanner, plug it in and see whats going on.

If you cant pin point the problem, disconnect your battery for 30 minutes and re-connect it and see if its any better.

Thats only going to mask the problem if indeed it has one. .
Jmac

[Jmac]

Sounds like a leak of some form. Polo GTI's don't have an idle valve, its all done by the throttle body.

Agreed, secondary air will cause that. If in doubt have it smoke tested to find the leak, these systems are in generalk pretty stable flashed or unflashed.
Jmac

[jesum]

would a leak in vacuum check valves cause this? part number 058-905-291-K. this valve is used in various locations in the car. i can easily see 3 when i open up the hood.