Douglashowes

Hi, I have a 2.0tdi year 2010 on 135,000 miles. Was recently loosing lots of Coolant and it turned out to the EGR cooler. Had this replaced but was still loosing Coolant. Put some steal seal in (https://www.steelseal.co.uk/) that seals headgaskets and other broken parts and it’s stopped the leak. However my Coolant system is very pressurised, the pipes are rock hard and there was air bubbles returning to the reservoir through both the return lines. There is no coolant loss just a very pressurised system. Had a block test done twice and there are no emissions within the Coolant system. Anyone had a similar issue? Garage is now saying it’s the head gasket but with no emissions in the coolant? Oil is fine and without leaks. IMG_1499.MP4

Diagnosed as faulty buzzer/ speaker

Audi Q5 2010 reversing sensors not working. No noise at all from the sensors. This is the model without the sensor display on the screen all i get is a noise normally. I’ve checked the fuse, reversing lights are on and I’ve checked all the sensors are plugged in. Any thoughts? Could it be the buzzer/ speaker? I believe the speaker is located by the rear glass, looks difficult to remove, does anyone know how and how to test the speaker? Thanks