Hi!
I own a 2010 Golf with a mere 75,000 km (~46,600 miles) on the clock with the turbocharged 1.4 liter engine. Bought it when it had run about 50,000 km and it has worked perfectly since.
A few weeks ago however I started experiencing some slight hesitation from the engine during acceleration under certain circumstances. I only noticed it between 1.5-2 k RPM and 3-3.5 k RPM. The sensation was as if I would be varying the throttle input at a constant rate even though I held it still and this would happen even on part throttle, around 50% on the pedal. As soon at it reached a magic threshold around 3-3.5 k however it started running really smooth, WOT or not.
Started suspecting the spark plugs as they had never been changed from what I could see from the service records, thinking that maybe there was an occasional misfire. Changing them had no effect however, the engine still behaved the same way.
Using a cheap OBD scanner I checked for fault codes - there were none and no logged ones either. I've also confirmed this with VCDS. Tried running some graphs while driving to see if the readouts seemed weird. The boost pressure and the engine load graphs both jump up and down a bit during acceleration as I feel the car hesitate. Also out of curiosity I checked the position of the throttle body and that reading too was jumping up and down during acceleration (though not above 3.5 k). I.e. the throttle is opening and closing slightly with a constant pedal input during acceleration rather than staying at the same position.
When applying gas the reading for the throttle position initially increases to match the pedal input as expected, then it dips down to about half the initial value, then it proceeds to fluctuate at a pretty constant rate, causing the uneven acceleration. It makes no difference if I am at part throttle or WOT. If I attempt the same thing in 2nd gear starting at 3 k however, the reading goes right up to its maximum value and remains there and everything feels as it should.
Any suggestions what could be causing this?
I own a 2010 Golf with a mere 75,000 km (~46,600 miles) on the clock with the turbocharged 1.4 liter engine. Bought it when it had run about 50,000 km and it has worked perfectly since.
A few weeks ago however I started experiencing some slight hesitation from the engine during acceleration under certain circumstances. I only noticed it between 1.5-2 k RPM and 3-3.5 k RPM. The sensation was as if I would be varying the throttle input at a constant rate even though I held it still and this would happen even on part throttle, around 50% on the pedal. As soon at it reached a magic threshold around 3-3.5 k however it started running really smooth, WOT or not.
Started suspecting the spark plugs as they had never been changed from what I could see from the service records, thinking that maybe there was an occasional misfire. Changing them had no effect however, the engine still behaved the same way.
Using a cheap OBD scanner I checked for fault codes - there were none and no logged ones either. I've also confirmed this with VCDS. Tried running some graphs while driving to see if the readouts seemed weird. The boost pressure and the engine load graphs both jump up and down a bit during acceleration as I feel the car hesitate. Also out of curiosity I checked the position of the throttle body and that reading too was jumping up and down during acceleration (though not above 3.5 k). I.e. the throttle is opening and closing slightly with a constant pedal input during acceleration rather than staying at the same position.
When applying gas the reading for the throttle position initially increases to match the pedal input as expected, then it dips down to about half the initial value, then it proceeds to fluctuate at a pretty constant rate, causing the uneven acceleration. It makes no difference if I am at part throttle or WOT. If I attempt the same thing in 2nd gear starting at 3 k however, the reading goes right up to its maximum value and remains there and everything feels as it should.
Any suggestions what could be causing this?