6R GTI misfiring

[JonW]

+1 to what Gavs said about this in general.

The bit i dont see is why you think the intake manifold would have carbon build up in it Gavs? I believe that the combustion chamber would have it but wouldnt expect it in the intakes unless the turbo was leaking oil or the valves/seals were shot. In my oil burning 1.4 the pistons had so much build up the workshop manager took pics as he was shocked by it, surprised it wasnt pinking etc. The pistons/rings were replaced and the head cleaned up. The oil came from under the pistons, up past the rings and into the combustion chamber. This could cause a misfire with oily plugs and pre ignition etc so sounds like they might be getting closer to understanding the issue and hence a fix.

[alexaescht]

+1 to what Gavs said about this in general.

The bit i dont see is why you think the intake manifold would have carbon build up in it Gavs? I believe that the combustion chamber would have it but wouldnt expect it in the intakes unless the turbo was leaking oil or the valves/seals were shot. In my oil burning 1.4 the pistons had so much build up the workshop manager took pics as he was shocked by it, surprised it wasnt pinking etc. The pistons/rings were replaced and the head cleaned up. The oil came from under the pistons, up past the rings and into the combustion chamber. This could cause a misfire with oily plugs and pre ignition etc so sounds like they might be getting closer to understanding the issue and hence a fix.

Carbon buildup in intake manifolds and the backs of intake valves is very common in DI engines as soot builds up from the EGR and doesn't get cleaned from the intake valves by the injectors (as they are located in the combustion chamber as opposed to upstream of the intake valves in non-DI engines).

[BenT]

Yesterday they said it looks like a couple of valves are "burnt". Should find out tomorrow if they're replacing any valves. Might not know if it actually fixes the misfire before this weekend though.


Sent from my iPhone using Tapatalk

[gavs]

Carbon buildup in intake manifolds and the backs of intake valves is very common in DI engines as soot builds up from the EGR and doesn't get cleaned from the intake valves by the injectors (as they are located in the combustion chamber as opposed to upstream of the intake valves in non-DI engines).

This is basically it.

What I'm saying is that if there wasn't any in the intake manifold yet the cylinder head that the intake manifold is bolted to is so bad that it needs removing and cleaning, how is the intake manifold clear of carbon build up....?

[JonW]

Cool ta for the info, always good to learn something about modern motors.

[BenT]

Today they told me they're going to have to replace the head and I should get the car back at the end of this week, 2 months since they first saw the car.


Sent from my iPhone using Tapatalk

[BenT]

And today they told me it won't be ready before next week. Also found out they're putting a brand new head on because a couple of the valve guides were worn.


Sent from my iPhone using Tapatalk

[ope126]

And so the plot thickens!!!

[BenT]

Latest update:

They have fitted the new head and the engine light came on again when the dealer test drove it. There was no apparent misfiring but the light came on none-the-less. So they've sent this info to VW Australia, and I assume they will forward it to Germany for the next suggestion.

[OilBurna]

Sorry to hear can't they check the error codes and try to diagnose? I thought they could connect online to Germany?


Sent from my iPhone using Tapatalk

[BenT]

I assume it's still just reporting random misfiring in multiple cylinders. That error code is not very helpful.


Sent from my iPhone using Tapatalk

[BenT]

On Monday this week they said the head replacement fix didn't solve the problem and they were waiting for more advice from VW. It's now Wednesday and still no progress.

Yesterday I rang VW customer service requesting a specific date for resolution and they promised to call back and I still haven't heard from them.

That's three times VW Customer Service have promised to call me and not done so.


Sent from my iPhone using Tapatalk

[OilBurna]

Sorry to hear keep trying call them every day if you have to have you been to Consumer Affairs yet? You deserve a replacement vehicle


Sent from my iPhone using Tapatalk

[BenT]

I can start the ball rolling with consumer affairs but it takes three months to get to court. Barely worth it.


Sent from my iPhone using Tapatalk

[BenT]

the VW service manager just called again and said its still faulty. Tomorrow morning they will replace the computer and let me know some time tomorrow if it is fixed.


Sent from my iPhone using Tapatalk