Hello all. Superb mark2 140 tdi cffb. I got VCDS a couple of years ago and scans have always shown that 2 glow plugs circuits give the 4985/P0672 fault in the circuit. It has never been a problem starting the car, until this winter as the temps have dropped to -3 or -4 overnight. Yesterday it took 3 attempts to get it going - and this was early afternoon after it had been sitting in full sunshine all morning.  I am going to get 4 new plugs and change them,  but is there anything else that may be causing this starting issue?

Thanks, Fats

Check the battery first. Battery is usually the main problem with starting it. The cold can sap the power. 

 

i had to replace my battery back in December. If you have a battery checker use that and see whether there is an issue with it. 

 

Symptoms start with the engine requiring longer to fire when turning over when its cold. 

Then when was the Air Filter last looked at and replaced if needed?

When was the fuel filter last replaced?

Air and fuel filters changed just over a year ago, only 10k miles on since then. I will check the battery, it is just 3 years old. 

On 12/01/2021 at 19:48, fatscoleymo said:

Air and fuel filters changed just over a year ago, only 10k miles on since then. I will check the battery, it is just 3 years old. 

It still sounds like a building battery issue. most batteries only have a life of 4-5 years but certainly with mine it required longer turning time to get it to fire up. 

 

I don't think you need to change it yet but just check the model of battery fitted and how long the battery life was warrantied for. 

 

Plenty of threads on here describing how the cars needed more time to turn over before it caught. Big cold engines and lots of power demands on the battery with all the toys that come with the cars now.