1.4 Tsi (160) rough idle, bouncing Rev counter and hesitatio

[josheades]

I have noticed recently when I start my car, it sometimes revs higher for a while then settles down, I thought nothing of it as it only happens occasionally, more recently I noticed its idling rough when sat at lights etc, I have also noticed it hesitating slightly when accelerating and the Rev counter bounces only slightly (around 50 revs) it only seems to do this when the engine is up too running temperature, I am completely puzzled what it could be as there are no fault lights on or anything, other than what I have previously mentioned the only other thing is a slight drop in mpg, a man from work suggested changing the air filter, this would explain the rough idle as it is asif its starved and going to stall,
Anybody on here have similar problems or a solution?
Thanks

[the_winner]

''I have noticed recently when I start my car, it sometimes revs higher for a while then settles down,'' this is absolutely normal
It will not change anything with air filter change .Please give some more info about the hesitation when you accelerate

[BishBashBosh]

I had this up at around the 70mph mark when accelerating. The exhaust emissions light eventually came on. After a couple of diagnostics, i had to have a new injector in cylinder 1 (they tried swapping around coil packs and spark plugs first, re-daignosing and coming up with the answer).
Purrs like a beauty again now.
Although there is a rattle/tapping sound under the bonnet when idling - but strangely enough not when the clutch pedal is depressed. Any ideas (sorry, should start a new thread rather than hijack this!)

[josheades]

The way I can best describe it is when you use the engine to slow down by downshifting, it's as if it does that for a split second and then accelerations or even when just plodding along at 30 I can feel it pulling me back, I'm more concerned about the rough idle at the minute as when it occurs it can be quite rough and other time it won't do it at all, I've had possible suggestions of air filter, spark plugs, coil packs etc, was just wondering if anyone has managed to pin point anything with the same problems

[therealtimmsy]

Hi mate, not to sound bleek, but i had the same problem when the fan on my turbo went.... or very similar at least and ive got the same engine. still in warranty?

[stanj028]

Sounds to me very much a coilpack issue! Do you have/know anyone with an OBD reader as this would show up!

[stanj028]

Out of interest, I have actually had the same issue with my 160TSI, do you occasionally get a random knocking noise extremely rarely from under the bonnet regardless of engine being hot or cold?

[josheades]

I have checked and there is no codes showing up, I took it to a vw specialist for diagnostics and again nothing showing up. Out of curiosity I replaced to spark plugs and it seemed to cure it however after a few days it was back, I am not trying running redex injector cleaner through but so far no good
Anybody got recommendations ?
As for the knocking noise I haven't noticed anything mate I will look out for it