Hi all, hoping for some guidance. started my car today which is parked in a basement garage in Sydney Australia. For the first time ever it spluttered and the engine stopped. Started again and gave it a rev and it spluttered a little and then smoothed out. Probably due for spark plugs and air filter - any other ideas of what to look at? Petrol 2015 plate Octavia VRS turbo petrol 2.0L engine completely stock.

Edited 14 May14 May by matt_g_VRS

How many miles on your plugs?

I do mine every 60k km

My vrs did it a while, took it to the dealer and they had an ecu update.

They injected it and problem solved.

So later the same day my car started overheating very quickly. I think it was likely my water pump that caused the spluttering start. Maybe the bearings jammed or the internals got to the point where they didn’t went to turn. Unlike when my thermostat went and the car went into limp mode this time it just got super hot, like to the max on the gauge reading and the dash just told me to turn the car off. Strangely when in neutral and not moving the temp gauge would move quickly to the colder direction and then bounce back to hot. It’s parks on the side of the road right now waiting to cool down. Will drive it early morning to mechanic tomorrow. Fingers crossed nothing more than water pump.

Is the engine really hotter than normal when opening the bonnet or just the gauge telling you it's overheating?

1 hour ago, ords said:

Is the engine really hotter than normal when opening the bonnet or just the gauge telling you it's overheating?

Actually didn’t seem hot at all. The fan would run on for half a minute or so but it wasn’t burning anywhere in the engine bay. Not sure how to read that other than something is broken and I don’t want to blow the engine.

These models have water pump Issues.

The cooling system is also managed electronicaly.

Do you have n'y record of a water pump job ? Did mine that was leaking last month at 121000km. The dealer told me he was amazed it lasted that Long. It's a 2014 tsi vrs.

Best Take it to the dealer for inspection.

Got to the car early this morning to drive to mechanic. Spluttering again on startup again like a bad misfire. Smoothed out pretty quick and drove fine for 10minutes. Temp started creeping up from 90. Hoping it’s a simple cheap fix 😵‍💫😵‍💫😵‍💫

On 18/05/2026 at 09:39, matt_g_VRS said:

Spluttering again on startup again like a bad misfire. Smoothed out

Did you check coolant etc after overheating?

Maybe water in the combustion chambers.

On 16/05/2026 at 05:47, matt_g_VRS said:

I think it was likely my water pump that caused the spluttering start. Maybe the bearings jammed or the internals got to the point where they didn’t went to turn

I can't see how a water pump could cause a misfire and stall. No way. If it jambed it would just snap the belt.

On 16/05/2026 at 05:47, matt_g_VRS said:

Strangely when in neutral and not moving the temp gauge would move quickly to the colder direction and then

Im thinking an electrical issue there. Bad earth....

29 minutes ago, BlueWagon said:

Did you check coolant etc after overheating?

Maybe water in the combustion chambers.

I can't see how a water pump could cause a misfire and stall. No way. If it jambed it would just snap the belt.

Im thinking an electrical issue there. Bad earth....

29 minutes ago, BlueWagon said:

Did you check coolant etc after overheating?

Maybe water in the combustion chambers.

I can't see how a water pump could cause a misfire and stall. No way. If it jambed it would just snap the belt.

Im thinking an electrical issue there. Bad earth....

29 minutes ago, BlueWagon said:

Did you check coolant etc after overheating?

Maybe water in the combustion chambers.

I can't see how a water pump could cause a misfire and stall. No way. If it jambed it would just snap the belt.

Im thinking an electrical issue there. Bad earth....

Yeah cheers for the input. Seems water pump is fine. Coolant was fine. No smoke so assume no water in combustion. Mechanic is diagnosing all of the temp sensors and parts and I’m away on a week holiday waiting for an update.

Update from mechanic. Coolant control valve confirmed to be faulty. Also changed temp sensor after that valve considering the games it was playing on me. Mechanic also mentioned all the crystals inside the coolant bottle had burst and been circulated through the coolant system so suggested best to drain everything and replace with new coolant bottle with fresh crystals. Never heard of these before. Pic of what I think the issue was with - I saw it on the bench and it looked just like this.

What you do is replace the Coolant Bottle with one without a Silica (Silicate) Bag. Then a different coolant should be used.

13 hours ago, Evolution13 said:

What you do is replace the Coolant Bottle with one without a Silica (Silicate) Bag. Then a different coolant should be used.

wich coolant?

I took my bag out 5 years ago and sticked with the same coolant.

What is the risk of keeping the same coolant?

AI has it right this time.

Interesting... dropped into the mechanic to change the coolant bottle this morning. Easy swap out. While the engine was hot the first thing he did was unplug the electrical connection - my old coolant bottle must have had a crack near the electrical connection - it was overflowing via the electrical port hole! Months down the line i assume potential for some water damage to the harness with this. Suggest changing the coolant bottle by 150k on the clock or sooner.

On 26/05/2026 at 14:11, Evolution13 said:

AI has it right this time.

car is going for a big servicing in 2 weeks, I asked them to flush the coolant and replace with G12EVO, only costs 17 euros more so perfect