Audi 80 B3 1.8: Persistent Interior Cold Air Issue Post-Bendix Replacement

Hello, I have an Audi 80 B3 1.8.

I have a problem heating inside the car. Some time ago everything was ok and it was very good. I couldn't stand it sometimes because it was hot. He was at the mechanic's to replace the bendix. After this period, these problems began. It is possible that this is a problem with it not venting. But I'll leave it to your opinion, because I don't know anymore. Today I changed the thermostat, but as you can see it was good because it is still the same problem. The temperature shows 50 degrees. The pointer will start for 3 lines and that's it. There is such a temperature all the time, and the fan turns on, i.e. the engine is already about 90-95 degrees. All tubes are warm.

What may be the problem?

Do you have a breather on the pipe to the heater? If so, it's worth using it, as you can't try to pull the return hose from the heater, but it's with your head, because it's easy to get a severe burn.

And what is the condition of the coolant at your friend's? Bigger / smaller / the same? After driving 2 - 3 km the upper pipe from the heat or cold radiator? Thick pipes to the radiator after warming up the engine are normal or hard, difficult to knead?

marqqv wrote:

And what is the condition of the coolant at your friend's? Bigger / smaller / the same? After driving 2 - 3 km the upper pipe from the heat or cold radiator? Thick pipes to the radiator after warming up the engine are normal or hard, difficult to knead?

I had a sensor down because it didn't show me the temperature. There was 2-3 lines and that's it. I exchanged and it's git. The pipe is warm. Everything works well in the pipes. It is possible that the problem was in the heater. Because the valves should have a sponge, and it crumbled on some and fell off. I covered the plates and everything is put on. The new heater was put in because this plastic had fallen apart, more precisely this tube from the heater and it was necessary to remove the entire interior and fold it. Tomorrow we will pass the test and let you know if it heats up. Because I have to pour the liquid and bleed it.

Added after 4 [minutes]:

Gunslinger wrote:

Do you have a breather on the pipe to the heater? If so, it's worth using it, as you can't try to pull the return hose from the heater, but it's with your head, because it's easy to get a severe burn.

Well, there is no vent. I took off this hose and vented just like that. But the heater tube was already broken and the second time wanting to do it broke completely. She's already broken from old age, I think. Because it is made of plastic. But everything is done, and as I wrote above, I pour in the liquid and bleed it tomorrow. I will let you know what effects