VW Polo – 1.2 Petrol – 2007 – Help Required Please

[aperson]

I have recently purchased a 1.2 petrol 70BHP Polo, it’s a 2007 with low mileage. It replaced my previous Polo which I had for 8 years and finally gave up the ghost at 14 years old. I have searched the threads in the forum here but none seem to match the exact nature of my fault.

I noticed recently an intermittent issue at idle, the RPM drop from the normal 800RPM to 300-400, at which point the engine nearly stalls, before the revs bounce back up to 900RPM before falling again to 300-400RPM. This yo-yo affect occurs another 3 or 4 times before self correcting. The issue is intermittent and happens every other day. When this occurs I have also noticed issues when revving the engine, if I rev the car to say 3500RPM then 1 out of 10 times the rev counter needle, and the engine pitch/tone, seems to take longer to drop to idle when I take my foot of the accelerator e.g. if normally from 3500RPM to 800RPM it takes 3 seconds then when the fault happens it take 6-8 seconds to drop to idle speeds. I even managed the other day to rev the car up to 3000RPM and when I took my foot of the accelerator the revs stayed at around 3000 RPM for 3 seconds or so, along with the engine revving at what sounded like 3000 RPM, before dropping back to idle. It seems to be more prominent when the engine is warm.

One point to note is when either of the above happens if I stick my foot under the accelerator pedal and pull it upwards the problem is resolved. It looks like the accelerator is fly by wire. The fact that I pull the accelerator pedal in an upward motion resets the idle immediately leads me to believe it may be an electronic issue with the accelerator pedal… but if this was the case why would engine temperature make any difference?

I am off to get a fault code read tomorrow night but any suggestions in the short term would be very much appreciated.

Cheers

Al

[boustie]

maybe a throttle clean and basic set ? or throttle body itself.

[aperson]

Thanks Bousite, I took the air filter out and checked the throttle body for debris which may have been causing a blockage/jam but everything looks ok. I squirted in some loose all for good measure. A fault code read and diagnostic with vagcom should no error's. Since the issue isn’t causing the car to stall and is more of an annoyance I think I will have to wait till it gets more regular.