Evening - I have a Skoda Fabia 1.6tdi 2010 with a coolant leak, i have had the system pressure tested and its fine, the leak is not visible. It can stay static for a month and then slowly start to drop over a week. I have noticed when the car is regenerating that the idle is lumpy (more than usual), and there is smoke coming from the exhaust for about 5 mins until i give it a blast. Any ideas ?

Something to check might be the EGR valve if your engine has one.

4 hours ago, Warrior193 said:

Something to check might be the EGR valve if your engine has one.

Will do, i think it does have.

At a guess it’s a CAYC engine? In which case it absolutely has an egr system , the cooler is buried down the back of the engine. Easiest way to get to look at it is from underneath with the tray off.

Lumpy idle during a regen is it trying to complete the cycle which should be done

“Between 2000-2500 rpm at a speed above 60kph” usually taking about 15-20mins at that speed and rpm consistently. I find 4th gear at 90kph is a nice middle ground unless I can get to a motorway.