Hi all,
I bought a 2006 VW Polo 1.4 FSI Sport a short while ago with 53000miles on the clock and full VW service history. The car is on a long life service regime at the moment.
Last week I took it to a VW Specialist garage for a service and new brakes. I mentioned to them that the car sometimes jerks quite violently at idle but the revs don't drop. I said I thought it was the compressor for the aircon, but even if you turn the A/C, it still does it. The car drives absolutely perfectly apart from this one annoyance.
Sometimes after a violent jerk, the car will start idling just under 1000rpm. It doesn't feel any different and after a few miles the needle will drop back to its original +-850rpm.
They hooked it up to the VW diagnostics machines but the ECU wasn't reporting any problems. They disconnected one coil pack at a time and the engine reacted like you'd expect. They say that it might have dirty valves. I've tried a tank of super unleaded (97RON) this week to see if that might help, but no such luck.
Any other ideas guys? I'm really hoping they don't have to remove the head like they said they might.
I bought a 2006 VW Polo 1.4 FSI Sport a short while ago with 53000miles on the clock and full VW service history. The car is on a long life service regime at the moment.
Last week I took it to a VW Specialist garage for a service and new brakes. I mentioned to them that the car sometimes jerks quite violently at idle but the revs don't drop. I said I thought it was the compressor for the aircon, but even if you turn the A/C, it still does it. The car drives absolutely perfectly apart from this one annoyance.
Sometimes after a violent jerk, the car will start idling just under 1000rpm. It doesn't feel any different and after a few miles the needle will drop back to its original +-850rpm.
They hooked it up to the VW diagnostics machines but the ECU wasn't reporting any problems. They disconnected one coil pack at a time and the engine reacted like you'd expect. They say that it might have dirty valves. I've tried a tank of super unleaded (97RON) this week to see if that might help, but no such luck.
Any other ideas guys? I'm really hoping they don't have to remove the head like they said they might.
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He did say that the air filter was quite clean for a car that's done 20000 miles since it's last service.