VRS Rough Idle

[NotSoSimple]

Hey Guys,

 

Have noticed that my TSI VRS (Man) has developed a fairly rough idle, regards of being cold or warm.

 

I only run it on VPower or Tesco 99, so I'm sure its not the fuel. Also replaced stock air filter with K&N one.

 

Have tried STP fuel system cleaner and this didn't make any difference. 

 

The interesting thing is there is no obvious loss of power - the acceleration is smooth.

 

Have booked in for the skoda mechs to take a look tomorrow. 

 

Anyone else experienced a rough idle with their TSI?

[Rooted]

A cheap and quick test is pop in a Fresh Clean OME Air Filter and see how it runs.

 rather than having in the 'Performance Filter' that might actually be reducing rather than increasing air flow and performance.

 

Just a thought.

 

Pitty you used the STP Fuel System cleaner,

that was not such a good move IMO.

 

george

Edited 24 July, 2014 by goneoffSKi

[Neily03]

A cheap and quick test is pop in a Fresh Clean OME Air Filter and see how it runs.

 rather than having in the 'Performance Filter' that might actually be reducing rather than increasing air flow and performance.

 

Yep, OEM air filter is definitly better than a K&N.

 

Pitty you used the STP Fuel System cleaner,

that was not such a good move IMO.

 

Agreed, and if your Skoda dealer finds out say goodbye to your warranty as VAG don't like fuel additives and it does say in the owners handbook not to use them.

[V6Jules]

Possible over oiling the K&N contaminating the MAF Meter? An aftermarket filter really will do bugger all

What sort of rough idle? Does the rpm hunt or is it just idling a bit too low?

Edited 24 July, 2014 by V6Jules

[NotSoSimple]

Had the K&N for about 4 months, havent cleaned it and re oiled as yet so i dont think this is the case. Will try with the OEM and see if any improvement. 

 

There is definitely a 'marmite' relationship with aftermarket filters heh! This letter from one of the k&n engineers made alot of sense to me - http://www.thedieselstop.com/contents/getitems.php3?K%26N%20Letter%20to%20The%20Editor

 

No it doesn't hunt - it just has slightly more vibration at idle than i can remember it having for the first 6 months - I have had the filter in for 4, no mechanical changes recently...

[V6Jules]

I use them occasionally but normally on bikes. I've seen a few tests in the past where air flow was measured and results showed the airbox or in the case of old flapper air flow sensors were far more of a restriction than the filter itself. I'm guessing the airbox opening is more of a limiting factor than the filter itself.

If your engine can be remapped to 300bhp with the original filter then it should be fine for a standard engine.

With very minimal gains to be had, I just change my standard filters regularly as they are cheap and efficient.

If it's vibrating at idle it suggests it might be just a touch slow? If you creep the rpm up does it smooth out?

[Frallan]

I had the exact symptom, if you have cruise control does it still work?

Mine started with the vibration and suddenly the cruise doesn't work. No information in the car menu..

No failures when I scan with vcds.. Only orange cruise symbol with "!" When I activate it..

[NotSoSimple]

OK, so got the car back from the garage.

 

There was an ECU update which they applied and they gave me a oem filter just to swap it out for a while and see what happens. Since leaving the garage i have had absolutely no rough idle at all. Unfortunately, because we changed two parameters i cannot know for sure which one is the cause until i can be bothered to put the k&n one back in!

 

However, the ECU has had a welcome boost to my indicated MPG. I normally get 320 miles to a tank (when the light comes on) and this only increases by 20 miles or so if i do long drives. Since the ECU update my indicated MPG and predicted range has increased by 2mpg and almost 60 miles more per tank!

 

Will see if it is the case, if so i am well chuffed!

Edited 29 July, 2014 by NotSoSimple