ok i have a 98 audi and recently my heater is only blowin cold air my temperature is going all the way till the warning light comes on and even my oil is gettin hotter all at the same time,i did replace the thermostat and the coolant temp sensor and it still doing the same thing,does anybody know what else it might be,any input would be great help.

 

Sounds like you have air bubble in the coolant lines. There is a bleeder screw on the heater core, or you can bleed through the drain on the radiator. Dont drive with it like that, you could warp a head and end up with a leaking head gasket [:'(]

 

yeah,i'm not driving it,it's been more than 2 weeks ,ever since i had to drill out the broken bolts on the exhaust manifold(yeah 2 out of 3 bolts snapped)then this started happening,i heard it could also be a water pump,coul it?

 

If it was your water pump, youd hear a gawdawful sound coming from it. The impellor is plastic (if not upgraded to the metal type) and shatters over time causing the bits of pieces to clank around inside the pump housing. Hopefully you didnt put the thermostat in backwards