Hi all, new to the forum so please be gentle. I drive a 2020 Superb 2.0tdi 190ps DSG, currently on 100,000 miles. About 8k miles ago I got the coolant level low ping up when I started the car. I topped it up, couldn't see any visible leaks so   carried on. This went on for a few days so took it into my local independent who pressure tested it and said it was fine and suggested we change the header tank (done).

Problem was still there so as the belt replacement was due in a few thousand miles changed the belt and water pump, whilst that was off also replaced the EGR cooler. (£2000 😪)

The coolant leak still not resolved I took it to another garage recommended to me by a friend who pressure tested it sent me a video saying that the intake manifold charge cooler is 100% leaking.

I then ordered the part (with the gaskets) from TPS £720 plus VAT.

Since the last pressure test I've done about 600 miles and the car has not dropped an iota of coolant. Yesterday as I was driving on a Dual carriage way the check water level light comes on and the temp gauge is close to the red line. I pulled over straight away and the gauge went back to 90.

Turned the car off looked under the bonnet and the coolant level was spot on. No steam or burning smell and pipes not hot to touch, started the car again and carried on another 80 miles and the car was fine. When I got home checked the coolant level and again bang on.

Now I've got this charge cooler in a box at home, the car has miraculously stopped burning coolant but I've had the temperature gauge tell me the car is running hot.

Has anyone experienced likewise or have any idea what's going on. I'm at my wit's end

Can you describe in more detail the over temp situation.

How quickly did the temp get up to red? And how quickly the coolant warning light went out after stopping?

Was the engine still running when you stopped and was it running while you waited for it to cool down?

 

It sounds a bit like an air lock in the system.

 

Can you cycle the heater on and off a bit to get any air out of there.

Maybe do this with the coolant tank lit open and engine running (not too hot obviously).

That might get the air moving to the tank where it should be.

 

Then recheck level when COLD.

I'd been driving for a while when the temperature went into the red then as I came to a standstill engine still running it was back down to 90.

 

Sliding sleeve sticking on the replacement water pump/

Any idea why doing the pressure test has stopped coolant loss? Was having to top up daily every 100 to 150 miles have done 700 ish miles since pressure test and not lost any coolant.