Merc007

Hello everyone,

I have a 2015 Audi SQ5 3.0bitdi (CGQ)

I have replaced the following already:

Waterpump
Thermostat
New Radiator
Coolant System flushed
EGR removed and blanked (software done)
DPF removed (software done)

I have checked that the cylinder head coolant valve solonoid is working.

I am at wits end, coolant tempreture would reach 120 to 125 degrees celcius when driving it hard. Coolant level will then drop by blowing it out of the radiator. Fans will be running full blast. Ive done a combustion gas in coolant test and nothing is found.

I just dont know what to try next.

atlanta A6

this almost sounds like you’ve got air in the cooling system somewhere. I’m not sure how to bleed out any air but that would be my focus

Merc007

Thanks for the reply. Ive got no idea how to bleed it even more.

This is the procedure ive been following:
Where the heatercore connects to the cooling system under the winscreen wiper motors. There is a pipe you can pull back with a small hole in it.

I fill the cooling system and close the lid of the coolant container and allow the car to reach 90°C with the heater on full blast. The I pull back that hose and allow air to escape until it only coolant coming out with no air. I do this in short bursts allowing the system to build up pressure after each bleed.

Am i missing anything?

Merc007

When I remove the top part of the coolant bottle there is little to no coolant flow into the coolant container. What could be blocking the flow of coolant? Does anybody know how the coolant flow of the coolant system on this car works?

Merc007

Mt output should be 90°C but its mid 20°C take it might be that the thermostat isnt opening?

Wires

I don't know how you bleed an Audi, but BMW has a specific service mode that you set the car in to prime the system from what I've read. If you have air, cooling efficiency drops, and temperatures rise.

The overflow tank gets any additional coolant that is forced out of the radiator when hot, and then sucks it back in when the system cools.