Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302

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Tue 11 Jul 2023 13:39
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan

Hi

Above car has erratic idle and slight misfire. Generally drives ok in higher ranges with full pulling power.

EML comes randomly on with P0302 code (Cylinder 2 misfire) and sometimes the Electronic Stability Control light as well. Changed plugs (long life) and leads but made no difference. Put a new coil pack on but it made no difference so have returned to the original one. I thought it was coil pack as 2 of the pins looked a bit corroded on original coil pack and 2 were bright shiny. Unless of course the new coil pack was faulty but unlikely I guess. Compression test is all fine.

Any ideas what is likely to be the cause. Could it be an injector and is there a way to check the injector.

Appreciate any help.

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Tue 11 Jul 2023 14:37
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - elekie&a/c doctor
Could be an injector, but access to them is difficult. It’s a hi pressure system which means the injectors are located below the inlet manifold . Don’t think there’s an easy way to test them .
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Tue 11 Jul 2023 15:42
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - sammy1

Might be carbon built up. Electrics side you have tried, have you tried internet search on the engine which is common in all the Audi VWs so try them all. Specialised injector cleaner as an alternative otherwise specialised testing firm or VW specialist garage Looking at a few searches could be a valve which is a major job I would get a few opinions as anything internal in the engine is expensive

1.2 Polo 55 55000 miles. - VW Polo engine mis fire cylinder 1...advice | UK Volkswagen Forum

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Tue 11 Jul 2023 16:42
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - elekie&a/c doctor
1.2 3 cylinder is not this engine .
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Tue 11 Jul 2023 17:13
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan

Its 4 cylinder

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Tue 11 Jul 2023 16:47
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - John F

I'd guess carbon build up too. Apparently VW/Audi group direct injection engines are more prone to this than other makes. Possibly because of the way the engine management system is set up? It's important the fuel burns cleanly. These little turbo engines have lots of low down torque so unless they are linked to an automatic gearbox it is easy to labour them at low revs in too high a gear when perhaps some of the injected fuel occasionally doesn't burn efficiently. I wonder if the problem is seen in cars with autoboxes which do not allow 'labouring'? Anyway, if it were mine I would try giving it a good thrashing with some regular 'italian tuneups' when well warmed up. That's what Mrs F's Peugeot 1.2 puretech engine gets when I drive it!

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Tue 11 Jul 2023 17:13
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan

Thanks for replies - much appreciated.

It is generally doing short school runs every day so I guess it could be an issue. Would you recommend something like REDEX cleaner or Dipetane fuel cleaner or what would you recommend?

Thanks again

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Tue 11 Jul 2023 18:35
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - sammy1

Thanks for replies - much appreciated.

It is generally doing short school runs every day so I guess it could be an issue. Would you recommend something like REDEX cleaner or Dipetane fuel cleaner or what would you recommend?

Thanks again

A double dose or more of Redex in the tank wont harm it. You might try a bit of redex in the dodgy cylinder overnight in case carbon on the top of the piston. A good blast in low gears to get the revs up is worth a try. As you say it is running so no point in spending big money

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Thu 13 Jul 2023 11:50
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan

How much would you pour into the cylinder to soak overnight. Is it safe to start up the next day or should the excess sitting in there be soaked up.

Thanks again - really appreciate the help

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Thu 13 Jul 2023 13:26
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - John F

It is generally doing short school runs every day so I guess it could be an issue. Would you recommend something like REDEX cleaner or Dipetane fuel cleaner.....?

No. The carbon build-up is on the back of the valves and their stems, not inside the combustion chamber. Sounds as though the engine never has to do much hot work as school run time is usually the busiest and slowest. It would be interesting see if thrashing it along a motorway in third gear for a few miles resulted in an improvement.

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Thu 13 Jul 2023 16:07
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - sammy1

It is generally doing short school runs every day so I guess it could be an issue. Would you recommend something like REDEX cleaner or Dipetane fuel cleaner.....?

No. The carbon build-up is on the back of the valves and their stems, not inside the combustion chamber. Sounds as though the engine never has to do much hot work as school run time is usually the busiest and slowest. It would be interesting see if thrashing it along a motorway in third gear for a few miles resulted in an improvement.

Tend to agree the culprit is more likely the valves and normally only the head off and a proper de-coke will fix . The Redex in the fuel may help the valves but worth trying a couple of thimbles of Redex on the piston head overnight.

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Thu 13 Jul 2023 16:31
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan

It broke a timing chain 2 years ago and had valves all replaced and new head gasket set etc. Car only has 75000km and always serviced. Shortly (1-2 weeks) after the overhaul it developed a problem which turned out to be a rocker arm so I had all of them replaced and it has been fine for the last 2 years.

Thanks again.

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Thu 13 Jul 2023 17:14
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Adampr

I take to the tensioner was done with the chain?

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Thu 13 Jul 2023 17:50
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan
Yes tensioner was done too.
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Mon 17 Jul 2023 21:08
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - Matt Kerrigan

Hi

Just to update, I have tried a few things:

1. Fit another new NGK coil pack to rule out the previous one. No difference made

2. Treated with redex in fuel tank and cylinder NO. 2 left to soak but no difference evident so far

3. Compression test all confirmed ok.

Thinking next step is check injector. Suspect this means intake manifold to be removed.

Appreciate any other ideas?

Thanks again

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Tue 18 Jul 2023 02:45
Skoda Octavia 1.2Tsi 2011 - Cylinder 2 Misfire P0302 - sajid

Do a italian tune up use third gear on the motorway run it for roughly 30 mins

Since the car been doing short runs this may help in burning out the carbon.

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