Octavia 1.8 TSI missfire on cyl 2/4 out of sudden

[Snowman89]

Today i was driving from point A to B, just pottling around when the car suddenly started jerking in a corner.

At first it just jerked in that corner but eventually it got worse in the upcoming 60second untill the CEL came on.

I stopped the car and turned the ignition off, the CEL came back and it still ran like ****..

I then parked the car safely next to the road and pulled out my obd reader, the codes i found was related to missfires on cyl 2 and 4.

After that i reset the error codes and swapped ignition coils on cyl 1 and 4 and tried again.

The car now barely starts and the error code is still at cyl 4, so its not related to the coils..

Also once i started the car and pushed the pedal loads of smoke poured out of the exhaust pipes and the car sounded like a 2-3cyl car.. The exhaust smelled very badly from unburnt fuel..

 

I had to call a tow truck since i didnt want to drive the care anymore..

Right now it is situated at my dealer, but they wont have time to look at the car until earliest mid next week.

The engine have been rebuilt by Skoda about 10000miles ago due to high oil consumption.

Does anyone haev any idea on what the issue might be?

I've done some googling and people are suggesting anything from injectors to bent valves or camchains that have jumped a tooth or two..

[mk2octavia]

What exactly is the fault code coming up on the obd?

 

[Snowman89]

16 minutes ago, mk2octavia said:

What exactly is the fault code coming up on the obd?

 

Didn't save them I'm afraid. 

But misfire cyl  2 and 4, think it was p0304 and p0302. After initial reset and I let it run for a short while (10-20s) just p0304. 

[mk2octavia]

Maybe its the spark plug?

You can try changing that and see what happens.....

If not, it can be the injector

If the engine has been rebuilt, a valve shouldn't go after 10k miles.

Do you still have any warranty left on the rebuild? 

[kton200281]

This is  your fuel injector stuck open. Exactly same symptoms as mine when this happened, on my 2.0 tsi. Will need to take manifold off to get to them, sounds like you may have had 2 fail but that would Be very unusual at the same time. 

Edited 9 December, 2017 by kton200281

[bigjohn]

Worried it might be the 1.8tsi cam chain issue. Stop driving until diagnosed to avoid this becoming more expensive to sort!

 

Edited 9 December, 2017 by bigjohn

[kton200281]

It is the fuel injector, why would a timing chain cause a smell of unburnt fuel. I don’t think there’s cause to assume all problems with these engines relate immediately to timing chains, and the symptoms don’t correlate either to a failed chain tensioner. 

[Snowman89]

19 minutes ago, kton200281 said:

It is the fuel injector, why would a timing chain cause a smell of unburnt fuel. I don’t think there’s cause to assume all problems with these engines relate immediately to timing chains, and the symptoms don’t correlate either to a failed chain tensioner. 

Yeah several people told me it most likely is a stuck injector.

After this happend i pulled over at once and it basicly only ran when i pulled onto the flatbed/towtruck and  then at the workshop where i took it off the towtruck.

Right now it is at my Skoda dealer which will be looking at it next week, however it would be interesting  if i would be possible to "brace" for the upcoming bill.. 

 

However, if it would be the injector why would it cause the idle to be rough (like its on 2-3cyl) with no smoke out of the exhaust.

But when i give it some gas there is ALOT of smoke coming out of the exhaust.

If the injector would be stuck open, would it not be that all the time which also would cause some smoke at idle?

Edited 9 December, 2017 by Snowman89

[Ju1ian1001]

2 hours ago, kton200281 said:

It is the fuel injector, why would a timing chain cause a smell of unburnt fuel. I don’t think there’s cause to assume all problems with these engines relate immediately to timing chains, and the symptoms don’t correlate either to a failed chain tensioner. 

Failed tensioner will cause the chain to jump, which will bend valve's, may only bend a few, if it bends inlet and exhaust valve's then there will be no compression in the affected cylinder's resulting in un burnt fuel. It may be possible for the engine to run but it will run very poor.

 

It may be a failed injector or 2, a complete VCDS will show injector and chain tensioner faults.

[kton200281]

5 hours ago, Ju1ian1001 said:

Failed tensioner will cause the chain to jump, which will bend valve's, may only bend a few, if it bends inlet and exhaust valve's then there will be no compression in the affected cylinder's resulting in un burnt fuel. It may be possible for the engine to run but it will run very poor.

 

It may be a failed injector or 2, a complete VCDS will show injector and chain tensioner faults.

I stand corrected - this sounds plausible too!

 I was making assumptions based on my experience - but could well be This...good luck in getting it fixed 

[Snowman89]

I will report back once the workshop has checked it out.

 

However this is starting to make me question these cars reliability, since i have had the car for almost 2years and i have had 2 mayor incidents..

If there is something "minor" like a injector stuck open i assume it will still cost anywhere from 500euro for replacing just 1 injector to 1000-2000euro replacing all 4..

Thats the cheap option considering that if the chain has jumped a couple of tooths i guess it will be alot more expensive..

[Snowman89]

Okay now the car have been fixed!

 

It did happend to be an injector that was broken/stuck open.

Is this a common problem?

The workshop just replaced the broken injector, so should i replace the other 3 aswell or is that not needed?

[mk2octavia]

Its up to you if you want to replace the rest of the injectors but you dont really have to as they are functioning correctly. 

[dilino]

Hello. CDAA.

During driving got very strong vibrations, white smoke, burned rubber smell, leaking fuel from engine, etc.

Car towed and injector 2 replaced (brand new bosch).

Engine runs well.

Drove the car 20 km and same symptoms again.

Towed again and mechanic says, injector 2 is melted again.

Could you please advise what could be the problem / how to possibly fix it.

5y ago pistons and chains were replaced.

NB card is fitted with LPG which was checked recently.

Thanks.

 

Edited 6 November, 2022 by dilino