So my audi only ever reached operating temperture during the summer now that its winter it never does but i pulled the thermostat and it does not apear to be stuck open infact it was holding back water when i pulled it out. Is there something else keeping my car from heating up. I cant remember the heat ever blowing very hot what so ever so unless both my radiater temp sending unit and heater core are bad i cant see anything really wrong with it. Any advice will be putting new thermostat in tomoro and will be going from there any advice would be appriciated. Also possibility that it opens fully at low tempertures a possibility?

 

Thermostat, regardless of how it looked, is common to cause this. How's your coolant level? I'd change the t-stat and the CTS and go from there.

 

^This. I just did my timing service and it turns out my t-stat was stuck open.

 

Tstat stuck open is such a common problem and not at all good for cold winter weather.

Did you take out the tstat and boil it in a pot of water to check that it actually closes and opens properly? I'd lay odds that the Tstat is stuck open and never moves (remember that a t-stat limits flow regardless even when 'stuck open' compared to not having a tstat at all) <-- many race drivers remove the tstat completely because of better cooling and flow for example.

If you have a new one next to the old one, do the boiling test with both and see what results you get (you might have an 'a-hah' moment seeing one 'stuck' open all the time while the new one opens and shuts like it should!

 

Thanks guys I'm gonna install the new failsafe one today but imthedevil what's the cts

 

And my coolant level was low but allways between the marks

 

CTS = Coolant Temp Sensor. It can cause all kinds of screwy stuff to happen. Top off your coolant too. The heating system/heater core is in parallel to the rest of the coolant pathways in the engine and is a very low-pressure part of the pathway compared to the rest of the system. Being low on coolant though, means you don't have enough to adequately fill the entire system, so your car's capacity to transfer heat from the engine to the heater core (where the blower motor will blow the heat into the cabin) is diminished. Get some G12 and top it off.