rough idling all the time

[Kish_A2]

Hi

My fsi has a rough idle problem the needle bounces between 800rpm and 2000rpm

It shakes the whole car and scares the s*** out of me

What could cause this?

Thank you in advance

 

[chb]

It could be an air leak somewhere, comparatively easy to fix, but might be tricky to find.
If its on the intake side then I would check the corrugated plastic pipes near the area of the radiator/engine oil filler cap....especially the one that is near the oil filter, I left this unclipped after a service last year and had 5 fault codes and really rough idle within 24hours of doing it!
Other things to check are the corrugated EGR pipe. This is the metal pipe on the passenger side of the engine. If it's failed (they all do eventually) then you will feel air "chuffing" out of the leak as the engine runs. If checking this last point then I suggest you check from cold so as not to burn your hand!
I think if it was injectors then you would have rough idle, but at a more constant RPM.
Does the car drive OK once throttle is applied?

 

[Birchall]

Hi

My fsi has a rough idle problem the needle bounces between 800rpm and 2000rpm

It shakes the whole car and scares the s*** out of me

What could cause this?

Thank you in advance

You need a VCDS scan ASAP, it sounds like the problem will show up if it is that bad.

As a guess I would say coil pack or inlet manifold but a scan will help identify the problem.

Steve B

 

[Kish_A2]

Looks like I'll have to get a scan done as soon as possible. Thank you guys for your help.

In regards to the last comment yep the car drives absolutely fine.

But pulling away in 1st gear or reversing the car the clutch then vibrates crazily that I end up stalling the car on occassions.

My last 1.6 was an FSI SE the clutch was smooth and perfect

My latest car is a FSI sport, not sure if that makes a difference?

Thanks

 

[Birchall]

Looks like I'll have to get a scan done as soon as possible. Thank you guys for your help.

In regards to the last comment yep the car drives absolutely fine.

But pulling away in 1st gear or reversing the car the clutch then vibrates crazily that I end up stalling the car on occassions.

My last 1.6 was an FSI SE the clutch was smooth and perfect

My latest car is a FSI sport, not sure if that makes a difference?

Thanks

The FSI in the sport is the same as a non-sport FSI.

It might not be clutch related, it is more likely to be due to a misfire that is making the car stall or almost stall.

So once you have had it scanned you will have a decent chance of identifying the problem which may well be a misfire and could be inlet manifold or coil problems.

The scan does not identify clutch problems, but whoever does your scan will be able to tell you if the car has a clutch problem or not by test driving it.

Steve B

 

[Kish_A2]

I Hey guys you know what's weird. My needle was jumping again so I left the car running and took the bonnet off.

Now I could hear a clicking sound if I turn the key just once to turn on dashboard lights

The clicking sound was a long "ticka-ticka-ticka-ticka-ticka-ticka"

At least 2 or 3 ticka sounds per second then it stops then I turn the key once more to start the engine and its rough idling

So back to the bonnet being off I removed the oil cap and the engine was going mad like proper shaking so I put the oil cap. Back on and I noticed there's a white plug going into the oil cap. Well I wiggled this white plug and the car idled back to normal and the car stop shaking.

Does this sound familiar to anyone?

Took the oil cap off again car goes violent. Put it back on car is okay. Oil cap when fully tightened still moves around. What would make the ticka sound?

 

[a2sumo]

Yes the breathing system is sealed circuit type and any air leaks such as cap off/dip stick out/ vac line unconnected will result in very poor idle. So it looks like you have fixed your issue, well done.mike

 

[chb]

If you have an air leak in the pipework near the oil filler cap then this will certainly cause rough idling.
You can take off the entire plastic oil filler housing (the bit the cap goes onto) It's just a push and twist bayonet fit. The various breather pipes can also be loose or leak near this area, fairly easy to check though! Hope it's a cheap fix.

 

[Kish_A2]

I hope it's a cheap fix too. Let's see what happens after I take it in for a scan next week

Cheers guys

 

[Bubonico]

Yes the breathing system is sealed circuit type and any air leaks such as cap off/dip stick out/ vac line unconnected will result in very poor idle. So it looks like you have fixed your issue, well done.mike

Hi @a2sumo my A2 eats oil, i believe it is because the piston rings of one piston. I think it is unusual since it has only 78.000km. I wanted to flush the engine to see if I could do some magic before i take the engine out.
When i opened to oil filler cap to fill it with the flush product the iddle when crazy and when i put the cap back on the engine sounded fine.
I understand by reading your comment that it is normal. Is it true?

Thanks!

 

[Birchall]

Yes on the petrol engined cars this happens. Sone people could fix their lumpy tickover just by making sure that the oil filler can has an air tight seal.

 

[a2sumo]

Hi @a2sumo my A2 eats oil, i believe it is because the piston rings of one piston. I think it is unusual since it has only 78.000km. I wanted to flush the engine to see if I could do some magic before i take the engine out.
When i opened to oil filler cap to fill it with the flush product the iddle when crazy and when i put the cap back on the engine sounded fine.
I understand by reading your comment that it is normal. Is it true?

Thanks!

Yes perfectly normal for a sealed breathing system engine.