Bora rough idle

[Spyda]

Having a slight issue with my girl friend's Bora.

Its not constant but usually happens with a lot of stop start driving like city or traffic.
The idle stays at about 800-900rpm but the engine shakes and it feels like a v8 with a big cam. The exhaust note is a very noticeable 'putt putt' and it also smells like egg farts. We checked the leads, coil, plugs to see if its running on 3 cylinders but its not and we filled it up with 98ron. It goes away after a bit of normal open road driving.

Anyone had a similar issue or can shed some light on this?

A search didn't turn up much but the closest i got was faulty MAF.

[dylan8]

MAF, o2 sensor?
Is the temperature gauge right on 90oC?

Might wanna put up what engine too (i cant remeber... 2lt?)

[Spyda]

Sorry its a 2l 8v.

Without an engine light on will a Vagcom pick it up?

[RolfGolf]

Without an engine light on will a Vagcom pick it up?

I'm thinking it should, but I'll defer to others with greater experience in this area ... When Gavin scanned my car he was able to show me coolant temperatures, voltages and all manner of things ... it's pretty specific.

[Back Door Shenanigans.]

I'd wager a vacuum leak. In start stop its loosing its vacuum in the brakes and reservoir and thus ****ty idle. Have a listen for a hissing sound if you can.

[Golf Loon]

I reckon vacuum leak too, take the cover off and look at all the plastic brether hoses around the engine. I bet one or more has a split and is loosing vacuum and oil.

[Spyda]

Cheers guys ill check it out.