1.8T AMB Coolant Circulation problem need HELP!

[lemon]

Hello i have big trouble with coolant, the water is not circulating well. It happened in winter when my heater was on. Suddenly I felt something like burning smell in the car and the heater started to blow cold air. Since that it blows only cold air. The heater works well only when I am driving on high RPM. First I thought that dirt was stuck in the radiator of the heater, but I removed hoses, started the engine and the water wasn’t spilling out. Only when I was giving a gas, little bit of water was starting to spill out. After that I thought that the problem was in water pump. I changed the pump, but nothing has changed. I still have the same problem. Can anybody help me?

[A4SoftWalker]

Sounds like a blocked heater core to me.
Try searching on here for the post of a kind member took the time to type up with pics included.
It has all the info u need.

Guess I'm in a good mood today... Hope others link to this excellent DIY from here too:



B6 A4 Heater Core Replacement DIY

[lemon]

thanks for reply but my heater core is working fine (tested with water not blocked) coolant not circulating normally in whole system and now i burned cylinder head gasket :(

[Charles.waite]

Have you checked your water pump? Sounds to me like the impeller broke loose and isn't circulating coolant properly...

[lemon]

I changed water pump and old one was fine

[boy412]

Thermostat?

[lemon]

Thermostat is working, opening big circle

[diagnosticator]

Thermostat is working, opening big circle

You may believe the t-stat is working, but it is the only device that could be the cause of the low coolant flow, that has not been replaced yet. The t-stats on our cars have a history of failiing eventually.

[Jeff]

Thermostat or Head Gasket. John (diagnosticator) knows what I'm talking about. ;)

Some people say our thermostats FAIL while "open", this is not true. I've seen them fail cracked half-way open--thus preventing coolant from flowing to the heater core properly.

[Charles.waite]

My B7's Thermostat failed in that it was fully closed when cold, but opened prematurely. If its not the Water pump, i concur with everyone above that its the thermostat. Get wrenching!

[MTS]

What are the engine temps doing? Most obd2 code can read live data, get the temps then make an assessment. Think I would try bleeding air out of the heater core first if engine temps are normal.

[lemon]

I have already tried bleeding air out of the heater core, i was reading live data with android device and engine temperature was jumping like 85-125C
Thank you all for your reply. I am going to check T-stat and change burned head gasket.

[POPO]

Are you sure you have enough coolant? I had problems getting air out my system after new turbo/water pump install. Today what I did when refilling the system was crack open the nut on the top hard coolant pipe then filled the reservoir. after I filled it, I lifted the reservoir in the air so that the coolant would flow faster into the system. I did this several times until coolant came out of the hard pipe. I topped of the coolant again and after starting up, I had no air in the system and the heat worked after about 2 or 3 mins. Hope this helps

[heateris]

I had the same problem with only getting heat a highway speeds. I flushed and bleed the heater core. Still had the same problem. I ended up having the heater core chemical soaked and power flushed. Fixed the problem.

[Myst420]

I didn't see anyone mention this, but have you checked your coolant flange? When mine leaked I didn't get any heat while sitting still.

Sent from my DROID RAZR using Tapatalk