I have changed the Tstat and the waterpump. coolant still steaming and bubbling in the resevior. What the hell??? any advice would be most appreciated at this point.

 

Well..... it could always be a bad head gasket.

But other than the bubbling.... are you having any problems with heat in the car or overheating the engine...?

 

I added coolant today and completing the timing belt and water pump. added coolant car warmed up and steam from the coolant tank. Only cold air coming out of the vents.

 

possibles...

air in the system. T-stat not installed properly/bad t-stat. pressure relief in the coolant cap is not pressure relieving. clogged heater core. small crack in coolant reservoir....

there are more.

good luck. keep us updated

 

i would examine your cooling lines. All of them. U might have a small leak allowing air to penetrate the system. You will need to fix that before the gurggle stops.

 

Even though mine is a B5 a4 i had same stuff happen too me, cold air blowing and so on. I took off the reservoir cap and held the gas at 2000RPMs for like 10 minutes and then my heat started working and the coolant level in the reservoir dropped since there was full circulation. My engine temperature also went back to the middle where it should be. Try that its a simple check

 

You have air in the system if you just replaced your timing belt.

You need to bleed the air out which can be tricky sometimes. I invested in a 160.00 vacuum bleeder that makes it painless. But its worth it to me because i do this quite frequently.

I would run the car with the resevoir cap of for 30-45 minutes at idle.

You need the thermostat to open with the cap off so the hot coolant will expand forcing the air to its weakest point which will be the open cap. With the cap on the air has no where to go and will just form a pocket

 

I just had an overheating problem today on my a6 2.7t. Changed the timing belt, water pump, t-stat, and valve cover gaskets 2 days ago. Was driving today, after about 30min of stop and go traffic the top radiator hose blew off, engine was extremely hot. Ill try this tomo and see if it helps.

 

I thought the 1.8 engine already has a bleeder screw on the top return line right next to the fuel rail. I know on some 1.8 the bleeder is plastic and on others it metal torx. IF u have plastic expect it to leak.

 

I agree with the guy above. When I changed my TB I had the same issue. Air is stuck in the pipes. I used the good ole fashion pump the hose at the top of the radiator method to get it to run through the system (while it was off and cold of course).