Audi A4 B8 2.0TDI - Coolant temperature drops down when heater on

[IgorUK]

So if you start your car and drive heater on...how long it takes car to warm up to 90 degrees?

You said dealer swapped many parts for test etc...what parts they tested?

Depends of the outside temperature,traffic and how hard you push the car. If its cold outside and stuck in traffic it wont warm up even after 1 hour driving. Dealership changed thermostat,and tested the water pump and egr valve,they have also checked hoses and pipes. Audi specialist tested the hoses that have thermostat in it and some sort of one way valve, and they also tested the heater control valve.

[IgorUK]

Is your car facelift? I've had the same problem with my b8 2008 2.0tdi 105kW and solve it with replacing hidden thermostat 1K0 121 113A which is placed in rubber hose 03L 121 157 B which connects egr cooler and oil cooler. That hose is not part of newer engines on facelift cars.

Yes is facelifted model. I think my car have that hose as audi specialist said they have tried to swap from another car but the issue was still the same. I will suggest audi dealership to do the same. The problem with dealership is that all communication goes throus service advisors and they dont have idea what are we talking about and they dont even listen.

[Gunnark100]

Do you guys have aux heater also?

[Audidua]

I dont have auxiliary heating only suplementary heater which isnt part of cooling system.

[Gunnark100]

I dont have auxiliary heating only suplementary heater which isnt part of cooling system.

Ok, in that case, this will not apply to you:
Audi A4 B8 2.0 TDI Diesel 130kw COOLING SELENOID VALVE WATER PUMP 4H0121671D | eBay

Just few reports from 130kw and this was a issue, without vcds error, but this valve is just front of aux heater by diagram, not in generic coolant diagram...

[IgorUK]

Do you guys have aux heater also?

I think that i also have the supplementary heater as when temperature below 7 degrees the cabin is getting warm even when coolant temperature is 0 degrees.

[Gunnark100]

I think that i also have the supplementary heater as when temperature below 7 degrees the cabin is getting warm even when coolant temperature is 0 degrees.

I dont have english copy(ATTACMENT), so use translate etc....do not show this to dealer otherwise they give you keys and say it is normal!

Was your climate update this action?
2013-16 A/C software upgrade service advisory issued - AudiWorld Forums

[IgorUK]

I dont have english copy(ATTACMENT), so use translate etc....do not show this to dealer otherwise they give you keys and say it is normal!

Was your climate update this action?
2013-16 A/C software upgrade service advisory issued - AudiWorld Forums

Im not sure about the climate update as i havent got the letter from them. They phoned me up and booked the car.The update took about 25 mins.
Ive read the russian file and i can say its a lot of crap in one file. I have my car for 2 and half years and this is first time to have this issue. Last 2 winters even on -10 the engine was warming up fast with heater/fan on full blast and coolant temp was staying on 90 degrees. The dealership is sending technical data to audi germany for now and waiting for advice. I will call the tommorow to ask if they checked the thermostat in the hose.

[Gunnark100]

Ive read the russian file and i can say its a lot of crap in one file.

I know its crap, but this is AUDI a.s cover crap...

As i read a bit this italiano thread, looks like there one guy did somekind of costum solution...as i guess egr termostat opens at 75 degrees and in traffic this will cause lower temps...
Anyway hopefully audi will resolve your issue...just dont take keys until it has been fixed!

[IgorUK]

I know its crap, but this is AUDI a.s cover crap...

As i read a bit this italiano thread, looks like there one guy did somekind of costum solution...as i guess egr termostat opens at 75 degrees and in traffic this will cause lower temps...
Anyway hopefully audi will resolve your issue...just dont take keys until it has been fixed!

The problem with audi dealerships is that they are going to start charging money soon, once they start charging i will have to take it back,as ive already spent a lot on it. At the end i might end up trading it in, i should swap the egr valve and tyres before that lol