MY12 Octavia RS TSI DSG 'Injector Fault'

[GamCem36]

G'day readers, (sorry for the story but any help is appreciated)

I've long followed the forum with only a few posts but now have an issue with my car..

I've had our car since new. It's always been run on Shell or BP 98 (fuel card for both). It's had every service completed by a Skoda dealer and has just clicked over 84000kms. I've not had any issues with the car up until now.

Issue: Started in Nov (as the warranty expired). I can only describe it as a 'jolting' at low speed (I'm aware of DSG slow speed jerkiness or hesitation) and it had not had this issue previously. The best I can describe it is a 'miss', like the car is dropping power. The acceleration was rough and 'spotty'. I had thought it was a DSG issue and tried to isolate. I tried manual mode, sport mode etc with no firm culprit. I did notice the car experiencing a rough idle when cold and especially when holding around 1000rpm it would seem to 'miss'. I wasn't sure if it was related so off to the only dealership in the NT.

Dealership first thought: DSG after a test drive.
They went to Skoda with no fault codes and described the symptoms. Skoda asked for a complete diagnosis (not sure of details) and report back. I went away for 12 days and heard nothing. Spoke to the dealership on return and they informed me Skoda could not identify the issue because they couldn't test drive the vehicle. I rang Skoda Aus for clarification and was assured that the issue would be sorted. The dealership were pushing for good will but I don't mind paying for it if it's not covered, I just want / need a fix!

After the call to Skoda Aus: Dealer calls saying a fault code has appeared (unsure of which).
Emails back and forth to Skoda Aus and the culprit is 'carbon build up' and requires 5 hours of work to remove intake manifold(?). Dealership pushed for good will but Skoda said it's not part of diagnosis or warranty.

Today: (3 weeks without a car)
Dealership have identified that injector 4 seems to be the issue which also requires intake manifold(?) to be removed. I'm pressing ahead but I'm worried that this could be 5 hours at my expense for no outcome. I'm planning to ring Skoda Aus again tomorrow but I'm in need of some advice.

Has any one experienced something or read of similar? I don't care much for the warranty / good will. I do want to hang Skoda for the diagnosis though as they've been insistent that it is carbon build up or an injector fault. If it's not I can't see why I'm up for the expense.

I've requested all communication between Skoda and the dealership and any work shop history they can give me. Service Rep isn't sure I'll get everything as it's not normal to do so.

Any help would be appreciated as I really just want a car!

[dArK5HaD0w]

crickey!!
hope ur issues are diagnosed correctly and sorted out quickly.

i haven't noticed/read about injector faults. maybe trying heading over the briskoda forum - they might be able to shed some light with ur issue?

[zei20t]

damn that's no good! hope its sorted.

also, the injectors aren't located in the manifold as the TSI engines are direct injection.

also +1 for briskoda. if anyone has had an issue, they will have had it.

[Lucas_R]

You need to remove the inlet manifold in order to access the injectors on these engines.

A failed injector is quite rare, whereas a injector that is partially blocked by carbon buildup is a more likely culprit - especially with 80,000km on the engine.

[Cheyne]

I had to have the injectors replaced in my Octy recently. Within about 10 months of being replaced, i had to have the Charcoal canister replaced.

[Umai Naa!!]

FSI injectors do fail, so not uncommon.

Get them to clean the carbon out as well.

[brad]

84,000km sounds about right for carbon build-up depending on the vehicle.

If they have to take the manifold off to clean out the carbon then they should also pull the injectors out (they are just below the inlet manifold) and clean / test them.

As a diagnostic technique you might try chemically cleaning the inlet & see if it improves the situation. It won't clean it out entirely but will get rid of a lot of gunk.

I use a mixture of 2 parts Kerosene: 2 parts Mineral Turps: 1 part Petrol & feed about 1 litre in through the air temp sensor hole while keeping the engine revving around 3000rpm.

[GTR27]

After much sucess with nulon foaming air intake cleaner on a heavily carboned motobike engine (like absoluely caked onto the inlet valves from running rich), i'm tempted to do it each service (like subaru's). Will likely do a 7.5K interim service and do it then to make sure its all squeaky clean. Seems to be a flaw with DI engines that they carbon up badly. The RS has two sets of injectors to overcome this now (a DI set, and a secondary set at low throttle openings to wash over the valves, and reduce carboning.). I assume most DI engines designed now will start coming with that setup

[Gerrycan]

After much sucess with nulon foaming air intake cleaner on a heavily carboned motobike engine (like absoluely caked onto the inlet valves from running rich), i'm tempted to do it each service (like subaru's). Will likely do a 7.5K interim service and do it then to make sure its all squeaky clean. Seems to be a flaw with DI engines that they carbon up badly. The RS has two sets of injectors to overcome this now (a DI set, and a secondary set at low throttle openings to wash over the valves, and reduce carboning.). I assume most DI engines designed now will start coming with that setup

If anything goes wrong during, or subsequent to, your application of the Nulon treatment then wouldn't the warranty be compromised? Probably undetectable though I suppose.
Would not have thought it would be necessary until about 30k or 2 year service.

I would be surprised if the low end engines like ours will ever receive two injectors per cylinder like the 2 litre does. Not sure about the 1.8 litre though, I thought I read somewhere that it does.

From my reading on the carbon build up subject, most of the problems seem to be associated with the EGR (pcv valving) system and lots of short cold journeys do not help.

[brad]

If anything goes wrong during, or subsequent to, your application of the Nulon treatment then wouldn't the warranty be compromised? Probably undetectable though I suppose.
Would not have thought it would be necessary until about 30k or 2 year service.

I would be surprised if the low end engines like ours will ever receive two injectors per cylinder like the 2 litre does. Not sure about the 1.8 litre though, I thought I read somewhere that it does.

From my reading on the carbon build up subject, most of the problems seem to be associated with the EGR (pcv valving) system and lots of short cold journeys do not help.

Doing anything not in the book could compromise warranty. That's where we toss a coin and decide if we take a chance. Getting VWA to warrant carbon build-up would be near impossible.

I'd like to thank you for the reminder. I fitted a Forge Catch Can to mine (possibly in October or November last year around the same time as the interim service but I didn't make note of the date). I checked it every couple of weeks and it didn't seem to be doing a thing and forgot about it & haven't checked it this year.

I just had a look (5000-7000km travelled) and the catch can was well over the max mark. I filled a 500ml jar with horrid brown water-like garbage and foamy scum.

My oil level is only down 3mm from the top of the cross-hatch.

I can imagine this goop going into the inlet, the water evaporating off and the remainder coating the valves.

80% of my journeys are 40km+. The engine gets nice warmed up nicely. BTW, EGR isn't tied into the PCV (as far as I can see).

Edit: Just found it - fitted 24/10/14 at 143500km. Now at 149500 = 6000km travelled