i just finished replacing the timing belt, thermostat, water pump, and valve cover gaskets. the timing belt was due for a change and the VCG's were leaking a bit. everything was put back together properly (hoses, wires, etc.). when i started my car everything seemed fine. took it for a ride up the road and i noticed my temperature was climbing and i had no heat. brought it back home and let it idle for a few minutes and the temperature leveled off...but still no heat.

when i first filled the coolant back up after i finished my work, i put in about four liters. after driving it i noticed it had gone down some so i added more because it is about a 6 liter system. ran the car again and it maintains a normal engine temperature at idle, but its only blowing cold air inside.

any suggestions would be helpful. only 11 degrees here today...i need heat.

by the way...98 A4 2.8
thanks

 

T-stat in backwards, upside down, faulty ... or air-lock?

 

t-stat was installed the right way. dont think it would be faulty since its brand new. i was thinking that it may be an airlock. gonna try everything else before i take it apart to remove the t-stat again.

 

first check for good flow from your water pump then bleed it properly. Did you pull the wiper cowl off and pull the heater hose back to bleed it? That's how it's supposed to be done unless you have the vacuum tool which you don't. Try this 2-3 times before you pull the tstat out. Make sure if it has a hole in it that it is facing 12 oclock upwards and that the spring is twards the block.

 

you might be suprised, ive seen some that dont work from the get go... thats why i always test them in boiling water before wasting my time.

 

i went back out and bled the heater core hose and the two bleeder screws in the order recommended in the haynes manual. ran the car and now i have heat! however...the lower radiator hose isnt getting hot. i let it idle for about 10 minutes and took it for a short drive. the temp gauge is saying its at normal temperature and not getting hot like it was before. im gonna go back out in the morning and bleed the system again and see how it works afterwards. thanks for your help

 

so it turned out to just be an airlock in the cooling system. bled the system a few more times and its running perfect. thanks for all the help.

 

how do you bleed the hoses?

 

like I said in post 5 pull the wiper cowl back and there is a hole in one of the heater hoses. You take the clamp off and stick a pin down the hole as you pull it back it'll match up to the pipe. This is the highest point of the coolant system so all the air will come out there.