update on my overheating audi, now bleeding the coolant system help needed

[kier1990]

I took the thermostat out my audi today, will try and upload a picture later.
Am hoping this is the problem looking at the state of it.

I have replaced the thermostat and have tried to bleed the system but haven't managed to get all the air out. I have no heating in the car. The bleed screw on the top of the pipe can't be undone, what other ways can I try to bleed it? Thanks

 

[Mike.M]

The system self bleeds.

Remove the cap on the overhead tank, put the climate controls on the hottest and fastest setting.....then keep revs about 2k to get temp up to 90 and keep it there while monitoring the water level and topping up.

This whole process should not take anymore than 30 minutes max

 

[Ian2012]

Correct me if i am wrong but i am sure one of the 2 hoses that goes through the bulkhead should have a little hole in it maybe under the hose clip, if you slide the hose off a little bit and let coolant /air out the the hole then this is how to bleed the heater

 

[SL11CKK]

Yep your correct on the TDIs - I don't know about the Petrols.

The two pipes going into the cabin are indeed the bleeding pipes well the one on the left. You need to undo the clip holding the hose and take it down a certain amount as there is little small hole on the pipe itself which will let all the air out.

Anyways I went by this guide How to do a VW Passat TDI coolant flush and change

 

[kier1990]

Have had a go this morning, as soon as car heats up to 90 and is running for about five minutes, the water bubbles out over, there is nothing coming out the bleed hole by the heater, the top of the radiator is hot, the bottom is cold, the small return pipe when taken off has steam coming out, the water is flowing out of the expansion tank out of the hole where the return pipe would be, this suggests the water is backing up the out pipe at the bottom of the expansion tank. Still got no heating in the car.

 

[adamss24]

Blown head gasket or cracked head...

 

[kier1990]

How does this stop the system bleeding? When I turn the radiator drain plug at the bottom of the radiator nothing is coming out. I have a head gasket test I can do on the car but I don't think it can be done when the water isn't circulating.

 

[s5joe]

It sounds like your putting the water in too fast or not squeezing the hoses to try and get the air out first. Try taking the top hose off and filling the rad though the top hose first to make sure it's not blocked

 

[kier1990]

I haven't put any water through it as it's not going around so can't pour any water through if that makes sense, tried pouring the water into the top of radiator yesterday but this doesn't seem to have made any difference, there is nothing coming out the bottom of the radiator so am assuming the radiator has a block.

 

[s5joe]

Sounds like it to me i would take it off and try it that way if it is blocked get it reconditioned

 

[Catcherofcarp50]

Hi there had similar problem on a mg and I pushed my hose pipe in it to see if there was any blockages and I took one hose off the heater matrix and put the hose in that hope you get it sorted

 

[kier1990]

Here is the thermostat once taken out, if picture has attached properly. I think I have now bled the system and it appears to be ok. Going to take it for a drive in a bit and check everything is ok.

 

[BakPak]

What's that lodged in the thermostat?

 

[s5joe]

That does not look rite it's as if the spring has snapped if so the water will not go around the engine properly

 

[Mike B]

The stat has stuck open which is what is intended.The wax inside has failed allowing the spring to extend