Started up my two year old 38k miles Octavia vRS TDi and was greeted with the message coolant issue. Car ran for 40 miles no problems with engine temperature normal.

When I used the car later, there was no message/issues. Should I be worried, or just a result of abnormally cold overnight temperatures?!

Check the coolant level.

Today must be the day for it, maybe with being a bit cooler but I've booked mine into the dealer as I had the message this morning and the coolant header was almost empty. To give Benfield/Lookers credit they offered to top it up while I was getting it booked in for a check next week.

 

I've decided to get the other warranty issues sorted at the same time.

Check what's in the expansion tank. You can either fill it up where it should be and see if it drops again over time; or take it to the dealer to check for leaks. Although they will likely fob you off by topping it up for you and telling you to see how it goes. 

I took it straight in and asked them to book it in to get this and a couple of other warranty things sorted. They topped it up while I was making the booking but I'll be watching for the next week.

Strangely, the service guy said they'd sideline the courtesy car for me for a couple of days as coolant issues can be a longer fix. I wonder whether he's half expecting water pump or other issues?

There must be an inherent design fault in the coolant system of the Octavia.  There are a large number of people who are reporting issues with low coolant levels.  I remember my Mk2 one day loosing the entire contents of the expansion tank.  I took it to a local dealer to where I was at the time, They topped it up and there is stayed until I sold it 2 years later.

I think it's quite a common for it to be a leak from faulty parts. When I had mine replaced they thought they could do it fairly quickly as they had a spare part in stock already, then they phoned and said it's actually another part that is also quite well known for leaking but they'd have to order it in.

 

Must have been a bad batch or design of part(s) installed across a particular time frame. Haven't really seen people with the newest Octavia's mentioning it as yet.

Colleague had this with a Leon FR when almost new, same engine. Topped it up and it's been okay in the 30,000+ miles since, no obvious leaks.  :S

Colleague had this with a Leon FR when almost new, same engine. Topped it up and it's been okay in the 30,000+ miles since, no obvious leaks.  :S

 

It's normal for the coolant level to drop over the first few hundred miles of a new engine. When the cooling system of an engine is filled from empty, you get little air bubbles in the system. These bubbles work their way out as the engine is run for the first few miles thereafter, thus dropping the visible coolant level in the expansion tank. Once the air has all escaped the system, the coolant level should not drop any further unless there is a leak somewhere.

It's normal for the coolant level to drop over the first few hundred miles of a new engine. When the cooling system of an engine is filled from empty, you get little air bubbles in the system. These bubbles work their way out as the engine is run for the first few miles thereafter, thus dropping the visible coolant level in the expansion tank. Once the air has all escaped the system, the coolant level should not drop any further unless there is a leak somewhere.

 

Yeah, I am aware of that, but this was basically empty. Sorry, should have made my first post a bit clearer.

Maybe it had only been filled up to the minimum level at the factory and/or there was an exceptionally large amount of air in it? Think it's quite common for the factories to only put in the minimum required, that way they save a lot of money. Only thing I can think of, it does sound a bit odd but if it had leaked from somewhere you would expect it to continue leaking.