Car not reaching running temp? :(

[MrPresident]

Morning All,

2004 Audi A4 B6 1.9tdi 130 Sport

Recently replaced the coolant flange at the rear of the engine and hose to the heater and filled up with new coolant if that could have anything to do with it. I've tried bleeding the system twice to see if that helps.

Basically the car used to get to 90c on the gauge and stay there. Now it only starts to climb in temp if I drive the car, idling barely moves it.

This morning I drove to work then drove in circles round the car park to bring the temp up close to 90c as I could. When parked it drops more. The Gauge shows abit below 90c and VCDS ranges between 75c - 80c max

Heres some images of the gauge and my reading from VCDS that I had running while driving.

I'm not sure how to diagnose it exactly and what to replace first

Click for Link to photos


Thank you

[Crasher]

Straight away something is wrong there, the gauge never tells the truth. I would suggest firstly you change the thermostat.

[MrPresident]

Straight away something is wrong there, the gauge never tells the truth. I would suggest firstly you change the thermostat.

Ordered thermostat off ECP, could go dealership but used Circoli Brand for my waterpump and no issues so far touch wood.

Circoli Thermostat | Euro Car Parts

Is there any diagnostics I can do really or just go straight in and replace it?

[Crasher]

The diagnostics you have done so far suggest the thermostat and what you are doing is what a mechanic would do.