Raffyrafs2s3

Hi,

I have a Audi S3 8v 2015. I had the common thermostat leak a few months ago and had the water pump and thermostat replaced. Since then i was getting rapid fluctuations in the coolant temp. I then replaced the coolant reservoir bottle as i had the p2556 code come on and stated coolant level sensor. After replacing this the code is still present but the fluctuations have calmed down. Car warms up within 5-10 mins of driving but now I notice that the coolant temp fluctuates between 80-105c. If i drive uphill it rises and then cools on downhill and when stationary. If it goes above 103c my fans kick in and they cool it down so im guessing it could be heading towards overheating if it wasn't for the fans. There are no visible leaks and the coolant reservoir stays stable. I've now also got a p2681 code stating the coolant bypass valves is open. Could this be the cause of the fluctuations I'm now getting?

Sorry if that is a lot of info but I've had nothing but issues since the initial leak on the thermostat housing which I know is a common fault on these.

Any help will be ideal thank you.

rdA4WtQ5

Sounds like the cooling system was not refilled (purged) correctly and there is air in the system.
Search for the procedure and and fix yourself (may require a vacuum pump) or contact your mechanic if you still trust them to do it.

Raffyrafs2s3

Thanka for your reply.
I've looked into getting the air out but there's so many different ways I'm unsure which to go with. How easy is it to get it all out without needing any extra equipment or anything? Thanks

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rdA4WtQ5

Some folks have reported success getting the front of the car higher on a steep driveway and running the the trapped air out. You want the car warm so that the thermostat is at least partially open. Pulling a vacuum at or near a heater core line is a typical method, not about the exact procedure for a transverse Ea888.

Raffyrafs2s3

​​​​​​I See. My driveway is on a steep so I will try that method. In terms of the vacuum for heater core line, so you have any instructions I could follow or a link which shows this being done? Thanks