Hello, easy one this (I suppose)

I have the flashing glow coil light on the dash, diagnostic says that there's an issue with No.4 glow plug. Is this the one nearest the front?

Thank you in advance

Glow plug 4 is cylinder 4, so typically furthest from timing belt on 2.0TDI. Personally, I’d be changing them all. Think OE is Beru and uses either deep 8mm or 10mm socket. Spray penetrating release such as PlusGas on all plug seats a few days prior to work and only once car to operating temperature. Use 3/8” or 1/4” ratchet, and don’t over-leverage. If it snaps you’re in a world of pain. Use smear of ceramic grease on new threads. Ensure the cylinder bore is spotless, you might need a vacuum cleaner to suck up any debris first, then microfibre rag on a flat head after removing plug. If not confident, leave it to a garage.

Thank you for the reply! I have changed the glow plugs out for bosch, they came out quite easily with a ten mill long reach socket but diagnostics still come up with the plug 4 fault. I reckon the wiring needs replacing. I did vacuum the bores out before removal of the old.

Looking to find a new glow plug harness then. Big bucks...

I had the whole inlet manifold off to clean the carbon off the swirl flaps so it was a fairly easy job to remove the plugs. Very well buried in the head, these things. I am surprised that audi didn't make them even more inaccessible..

On 5/16/2026 at 9:24 AM, Bun said:

I had the whole inlet manifold off to clean the carbon off the swirl flaps so it was a fairly easy job to remove the plugs. Very well buried in the head, these things. I am surprised that audi didn't make them even more inaccessible..

Should be good for 80-100k miles if not longer. Doubt Audi had your thoughts on access when they built the engine! Just watched a video on I think it was Kia or Hyundai rear break pads, to access rear carrier, one of the rear arms and the shock absorber needs to be removed to access the bolt, I mean, what the actual?

Regards harness, search Charles Trent. I’d be very sceptical of anything from breakeryard.com

Thank you!