Hi everyone,

since last december, my 2012 Octavia Wagon TDI RS started showing glow plug indicator. At the beginning, this was very occasional, like once a month or maybe less, but in the last 3 months it's happening more often and on the last weeks it's basically persistent.

As I am using Torque app connected through ELM327 OBD device, I could see the error is almost always P2564, and sometime P2563. Doing a research on the web, the most common cause seems to be the VNT actuator, which needs to be replaced, but it can also be the turbo variable geometry or the turbo itself.

I think I can exclude faulty wirings as the issue appears all the time in the same condition: when I am driving normally, no issues at all, but whenever I slow down like below 10km/h or I completely stop the car, the light turn on and the car goes in limp mode. Luckily I can clear the error and then comes back to normal, but I have to do this while moving otherwise the error will appear immediately again, so it seems this is related to the boost pressure. Using Torque, I also noticed when the engine is idle, the boost indicator switches to "vacuum" and it shows negative values. When I don't have the problem I have a value of -0.69, while when the problem appears is around -0.99 and it can go as low as -1.6.

 

This said, do you think it can be still related to the VNT actuator or it can be the turbo? When I clear the error, the car works normally, I cannot notice any power loss or strange noises from the turbo.

 

Unfortunately I recently moved on a new town and I still don't have a thrusted mechanic.. I wanted to ask an opinion here because as usual there is a risk the mechanic makes you pay the most even if it's a simple problem..

I had similar problems in my 1.9tdi It would go into limp mode randomly. If I stopped car and restarted and it was fine for a random amount of time. It did get progressively worse. Think it was the same error code. My turbo is VNT. I tried manually operating the actuator and it seemed very stiff and sticking at one point. I sprayed the actuator with some penetrating oil and spent ages operating it by hand. It eventually became easier and stopped sticking. Seems to have cured the problem. I assumed it was a vaccum problem and the garage assumed it was the veins on the turbo that were stuck. Might be worth a look

Alasdair

If its the turbo veins stuck I have seen folks recomending spraying Mr Muscle oven cleaner into it to clear the carbon. Never tried it as it to me seems a bit dodgy. Read something about not getting the cleaner on alloy as it tends to eat it. Hope its just a stuck actuator. There is on mine a vaccum unit on top of engine to the right of the egr valve that I assume does EGR and turbo etc. I originally bought a replacement for about £30-00 on ebay as I wrongly assumed it was the problem. It could also be the diaphram in the actuator that has gone. I don't think they are repairable. If it wont free up then a replacement isn't too expensive. I remember finding a few on ebay for around £40-00. I put the car on a couple of ramps and removed undertray to get to it. Not the most accessible place and you get a sore neck while your at it. Would be a lot easier on garage lift.

Alasdair