Hi wondering if anyone can help just bought a 2016 1.2tsi fabia, car ok then suddenly it starts to misfire on coasting not under load comes up with no obd codes had into local garage unable to find problem put new plugs in to no joy, any help would be appreciated 

You would be far better off posting in the Fabia forum not the Octavia forum....

Welcome to the forum.

 

A mod can move your post i will flag it. 

 

So how many miles has the car done,

So the spark plugs are changed ( 40,000 miles or 4 years as per Skoda recommendations, guidelines or even schedule)

 

The Ignition Coils need checked.  

 

Misfire fault codes might not come up if not enough in a cycle.

 

Go fill the tank with E5 97/99 Ron  Super Unleaded and see how things are rather than E10 95 ron. 

The Plugs need checked again though, then the coils and a clean Air Filter. 

??

Which spark plugs have they fitted? 

 

The Timing belt change was due at 5 years, but that is unlikely the issue if not done.

?

Has it bee changed? 

 

Edited 4 February, 20233 yr by toot

Please note - I am not a mechanic or expert in anything.

 

As has been plus, what servicing and maintenance work do you have proof has been done?

 

Was the battery checked for state of charge and state of health, is it the original factory battery or has it been changed?

 

Was the alternator also tested?

 

Did the local garage have a scan tool suited to VW systems?

 

When the spark plugs were changed was the air filter also changed?

 

As has been put you could fill with a couple of tankfuls of E5 labelled petrol for the cleaning additive packages and when the engine is fully warmed (check your oil temperature for 90c, ignore water temperature than will show 90 before oil) give the car a good (but sensible) blow out run, lower gears with higher revs over a reasonable distance journey on roads that can also exercise the gears/clutch, steering and brakes, it'll also help you learn the car.

 

Edited 4 February, 20233 yr by nta16

3 hours ago, toot said:

Welcome to the forum.

 

A mod can move your post i will flag it. 

 

So how many miles has the car done,

So the spark plugs are changed ( 40,000 miles or 4 years as per Skoda recommendations, guidelines or even schedule)

 

The Ignition Coils need checked.  

 

Misfire fault codes might not come up if not enough in a cycle.

 

Go fill the tank with E5 97/99 Ron  Super Unleaded and see how things are rather than E10 95 ron. 

The Plugs need checked again though, then the coils and a clean Air Filter. 

??

Which spark plugs have they fitted? 

 

The Timing belt change was due at 5 years, but that is unlikely the issue if not done.

?

Has it bee changed? 

 

/cdn-cgi/mirage/190e0babfd6bd9663f569518f878643094c11ca8ce9e61d9b9bba60525b67069/1280/https://www.briskoda.net/forums/uploads/monthly_2023_02/922218293_Screenshot2022-09-2115_58_57.jpg.3711dc86397a804fc83f268add4ae736.jpg.ece7ad63bf3be1dd444132de450cade0.thumb.jpg.a761f82eb1275eeb595494ce831ed2ae.jpg

Hi toot

 

The car has 45000 miles and has had the timing belt done , water pump done, new plugs done on Thursday gone and this morning I filled it with supreme unleaded with a cleaning agent ( Redex ) if that fails I will invest in a new set of coils cheers for your help 

The Redex was a waste.

I paid for my first moped in the days before unleaded petrol working at a filling station and selling 2 shots of Redex per gallon. I earned extra for that & tips.

 

Do not invest in new coils if new coils are not required.    

?

What are the spark plugs that were fitted and what was the gap they came pre-gapped at and checked?

 

The members that know your engine will be along.

http://briskoda.net/forums/topic/506382-12-tsi-running-rough-after-cambelt-change

 

 

 

Edited 4 February, 20233 yr by toot

Hi, 

The garage put Skoda vag plugs in don’t know if they actually gapped them, filled with supreme unleaded haven’t done enough miles to see any difference yet but still stumbling low down but pulls like a train  with no misfire going to 70mph and stays there no problem 

The spark plugs are pre-gapped so as long as the correct plugs that is not an issue, and you check they are all correct then not knock them when fitting.

 

It is good to see or be told what the plugs that came out were like, and measure the gap they had. 

A failing plug can cause an ignition coil to fail prematurely.

 

Not all e5 Super Unleaded is equal, but they will meet the Minimum Octane and have detergents.

Once an engine starts to get a bit of a clean out it can have a bit of a while until carbon or crap is moving. 

 

Getting the engine oil up to heat and the plugs and a run is not a waste of fuel to see how things are. 

 

Maybe old pre winter grade  E10 (more hygroscopic) petrol in the tank was all that was wrong. 

And a bit of oiled / carboned up plugs.