Intermittent shudder / misfire Fabia VRS MK2

[wah007]

Hello, 

 

I was wondering if someone can help with this issue I have with the car.

My car has started to intermittently shudder / misfire when driving after the car has warmed up. It's only noticeable when I try maintaining speed, i.e driving at a steady speed of 30mph or 70mph on the motorway. 

 

When stopped at traffic lights the Rev needle keeps jumping up and down after every couple of seconds to the point where it feels like the car is about to stall.

The car isn't throwing up any codes and there's no EML light on the dash. 

 

It was quite bad today (rough idle), and on some days it doesn't happen and drives fine with no shudder or rough idle.

 

I had it fully serviced around 3 months ago and had new NGK iridium spark plugs, oil / filter, air filters fitted. The year before that I had a new fuel filter fitted when serviced.

 

My car's a Fabia VRS DSG 1.4 Petrol MK2 2014.

 

Any ideas on what it could be?

 

 

Thanks 

Edited 9 February, 2023 by wah007

[thomasaspin]

9 hours ago, wah007 said:

Hello, 

 

I was wondering if someone can help with this issue I have with the car.

My car has started to intermittently shudder / misfire when driving after the car has warmed up. It's only noticeable when I try maintaining speed, i.e driving at a steady speed of 30mph or 70mph on the motorway. 

 

When stopped at traffic lights the Rev needle keeps jumping up and down after every couple of seconds to the point where it feels like the car is about to stall.

The car isn't throwing up any codes and there's no EML light on the dash. 

 

It was quite bad today (rough idle), and on some days it doesn't happen and drives fine with no shudder or rough idle.

 

I had it fully serviced around 3 months ago and had new NGK iridium spark plugs, oil / filter, air filters fitted. The year before that I had a new fuel filter fitted when serviced.

 

My car's a Fabia VRS DSG 1.4 Petrol MK2 2014.

 

Any ideas on what it could be?

 

 

Thanks 

Sounds like they have damaged the vacuum pipe while changing the plugs , there’s a few posts on here about it , if not they could have damaged the coil packs / wiring and or not correct spark plugs at correct gap 

[wah007]

3 minutes ago, thomasaspin said:

Sounds like they have damaged the vacuum pipe while changing the plugs , there’s a few posts on here about it , if not they could have damaged the coil packs / wiring and or not correct spark plugs at correct gap 

 

Thanks. Can you recommend anyone that knows what they're doing to diagnose this, in the Oldham / Manchester area?

 

The spark plugs that were replaced were NGK laser iridium SIZFR6B8EG (replaced with the same).

[wah007]

The engine management light popped up this morning when I first started the car. I read the codes with a standard scanner and it showed code p0106. Map circuit?

[thomasaspin]

I myself live in oldham if you need any help 

[thomasaspin]

You should be running NGK BKrie7 spark plugs 

[thomasaspin]

I run these plugs gapped at 0.6mm 

https://www.akstuning.co.uk/shop/home/119-ngk-bkr7eix-iridium-spark-plugs-2667.html

[Crasher]

Does the rev counter jump wildly, actually dropping to zero and then back up to 900 ish? On ETKA, the VAG spec for the plugs in a CAVE engine is NGK PZFR6R VAG number 03C 905 601 B but that cross references to an NGK SIZFR6B8EG which is highly confusing. The BKR7EIX is an interesting choice, its only VAG listing is for a 996 Porsche 911 GT2, GT3 and turbo.

[Crasher]

Also, the factory spec gap is 0.8>0.9 mm

[wah007]

@thomasaspin

 

Thanks mate, I've had the same plugs in the car before I replaced them and the car ran perfectly for a year.

 

I appreciate that, I'll PM you.

Edited 10 February, 2023 by wah007

[wah007]

@Crasher

 

Yeah the rev needle jumps close to 0 and then back up again, yesterday it was so bad that I thought that the engine was going to stall at the traffic lights.

 

It doesn't always do it, some days it's minor and on some days it's really bad with the stutter whilst driving (light throttle), and the rough idle.

 

Today the EML light came up on the dash and the DTC scanner showed code P0106.

[thomasaspin]

4 hours ago, Crasher said:

Also, the factory spec gap is 0.8>0.9 mm

As someone who has had a twincharger since 2014 I think I know the best gap to run mate , cars where failing with factory spec coil & plugs gapped at what you have listed 

[sepulchrave]

4 hours ago, Crasher said:

Also, the factory spec gap is 0.8>0.9 mm

 

The big gap is what kills the coil packs, hence running a smaller gap reduces the voltage requirements and the coil packs live longer.

[Crasher]

1 hour ago, thomasaspin said:

As someone who has had a twincharger since 2014 I think I know the best gap to run mate , cars where failing with factory spec coil & plugs gapped at what you have listed 

 

FFS, people don't half get up their arse on here, I was only quoting ELSA! Do you shout at the worksop manual?

 

 

Edited 10 February, 2023 by Crasher

[Ootohere]

Skoda / VW changed the spark plugs before the CTHE was used and the CAVE discontinued and the gap was reduced.

Audi techs had already stopped using either of these plugs on A1 195 ps 1.4 TSFI's. 

 

03C905601B / NGK SIZFR6B8FG were a 0.7mm gap. 

sadly, these were fitted to many a Twincharger with issues.  Caused the issues along with the other well documented faults.

 

 

http://briskoda.net/forums/topic/371770-spark-plugs-for-mk2-fabia-vrs

 

[Crasher]

5 hours ago, wah007 said:

@Crasher

 

Yeah the rev needle jumps close to 0 and then back up again, yesterday it was so bad that I thought that the engine was going to stall at the traffic lights.

 

It doesn't always do it, some days it's minor and on some days it's really bad with the stutter whilst driving (light throttle), and the rough idle.

 

Today the EML light came up on the dash and the DTC scanner showed code P0106.

 

That is a very strong indication of a failing crank speed sensor G28, these have a nasty habit of not showing up as a code so I depend on that as a clue.

 

16490 (P0106) - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal

 

I would, for now, judge that more as a result than a reason. Certainly based on what you say I would do the G28 first but on the CAVE it is evil to get at as the compressor has to come off which as you probaly know is a LOT of work.

 

 

[thomasaspin]

3 minutes ago, Crasher said:

 

That is a very strong indication of a failing crank speed sensor G28, these have a nasty habit of not showing up as a code so I depend on that as a clue.

 

16490 (P0106) - Manifold / Barometric Pressure Sensor (G71) / (F96): Implausible Signal

 

I would, for now, judge that more as a result than a reason. Certainly based on what you say I would do the G28 first but on the CAVE it is evil to get at as the compressor has to come off which as you probaly know is a LOT of work.

 

 

 

If you read the OP’s initial post you would see it started doing this after a spark plug change indicating that a vacuum hose has been damaged behind the coil packs (common problem on 1.4 twin chargers) 

[Ootohere]

A small point, not important, but for future reference the OP has a CTHE engine not a CAVE. 

http://briskoda.net/forums/topic/279292-cthecave-enginewhats-the-difference

 

 

 

Edited 10 February, 2023 by toot

[Crasher]

15 minutes ago, toot said:

Skoda / VW changed the spark plugs before the CTHE was used and the CAVE discontinued and the gap was reduced.

Audi techs had already stopped using either of these plugs on A1 195 ps 1.4 TSFI's. 

 

03C905601B / NGK SIZFR6B8FG were a 0.7mm gap. 

sadly, these were fitted to many a Twincharger with issues.  Caused the issues along with the other well documented faults.

 

 

http://briskoda.net/forums/topic/371770-spark-plugs-for-mk2-fabia-vrs

 

 

It is unusual for the VAG data on ETKA to conflict with the NGK list and Tecdoc. I was going to get a genuine 03C 905 601 B up from TPS but they don't stock them

[Crasher]

11 minutes ago, thomasaspin said:

If you read the OP’s initial post you would see it started doing this after a spark plug change indicating that a vacuum hose has been damaged behind the coil packs (common problem on 1.4 twin chargers) 

 

That wouldn't cause the rev counter to dip violently. 

Edited 10 February, 2023 by Crasher

[thomasaspin]

I have not in the history of this forum ever seen anyone with the problems listed above sort it out by replacing the crank speed sensor as it just stops the car from starting if it does go faulty  I will however eat humble pie if it is that at fault but I have had the exact same problems the op has stated in the past and both times it’s been either a vacuum leak or a faulty map sensor as these engines do not run a MAF sensor so rely on the map sensors for most things 

[wah007]

1 hour ago, thomasaspin said:

If you read the OP’s initial post you would see it started doing this after a spark plug change indicating that a vacuum hose has been damaged behind the coil packs (common problem on 1.4 twin chargers) 

 

Thanks all for the replies.

 

Yeah, I had the car serviced around 3 months ago with new NGK iridium (SIZFR6B8EG) spark plugs, oil, oil filter and air filter. These are the exact same parts that I bought and had fitted in the last service I had done around a year ago, except for the spark plugs as they were already in there before I bought the car, but they were the same NGK iridium ones. The shuddering issue only started around a month ago, about a week after I got the brake discs / pads changed. The car previously ran perfectly fine for a year with no issues whatsoever.

 

The car does have an RTMG dump valve and R8 coil packs, all done by previous owner.

Edited 10 February, 2023 by wah007

[Ootohere]

http://briskoda.net/forums/topic/438447-2012-2014-cthe-mk2-fabia-vrs-timing-chain-issues/page/2

see post by @pearce_jj

http://briskoda.net/forums/topic/435977-timing-chain

 

 

??

Are you using E5 Super Unleaded 97 or 99 ron, or E10 95 Unleaded? 

Edited 10 February, 2023 by toot

[wah007]

55 minutes ago, toot said:

http://briskoda.net/forums/topic/438447-2012-2014-cthe-mk2-fabia-vrs-timing-chain-issues/page/2

see post by @pearce_jj

http://briskoda.net/forums/topic/435977-timing-chain

 

 

??

Are you using E5 Super Unleaded 97 or 99 ron, or E10 95 Unleaded? 

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Since I've had the car I have only ever used Shell V power 99 or Esso Synergy Supreme+ 99 petrol.

 

I filled up with standard shell 95 once only as I couldn't find the premium fuel anywhere and the car didn't run smooth. 

Edited 10 February, 2023 by wah007
Synergy Supreme+ 99

[Ootohere]

Try a tank of Tesco Momentum 99.   

 The Esso Synergy 99* does come from Greenergy in parts of the country, see that chart,  Greenergy are the people also producing the Tesco Momentum 99 as well and part owned by Tesco and import the fuels along with Royal Dutch Shell but there are difference.

I liked the Ethanol.  

The Super Unleaded like the unleaded is winter spec until the end of March.   Nothing lost trying the Momentum.  the 99 ron is a Minimum.