2005 Audi A3 1.9 TDi not heating up

[S2central.net]

Not my car - just trying to help someone else zoom on a problem. I have a vague memory of some oddball heating setup on the 1.9TDi engines as they are naturally quite efficient and don't heat the water very quickly.

The patient has had a new thermostat and water pump as the engine temp showed low all the time. It still doesnt get up to proper water temp which has me thinking airlock or a faulty water temp sensor.

Is there anything else specific on the 1.9TDi to look at in this area ? I have surfed round a few other Audi forums but not found anything significant.

[baltiboyS2]

Cant remeber if that model had a heater control valve fitted these can cause issues
How long does it take to get up to temp ??

cheers Raj

[baltiboyS2]

Tell you what just a thought has the heating problem started during the cold months ??
as my 80 TDI will not go past the 3 lines on the start of the guage have put cardboard doen the front of the rad and blocked off 3/4 of the Rad it now runs up to temp no bother now
there was no fault during the warmer month's

cheers Raj

[S2central.net]

The owner just got the car a week or so back - so he has no feel for what is normal on these cars... doesn't get to temp even on long journeys. I have seen other threads about control flaps causing issues with control of cabin temperature. The owner is a long time mechanic and a bit confused by this one as it had all the symptoms of a thermostat stuck open.

[baltiboyS2]

Would agree sounds like stat but you have changed that i just did 40 mile trip and had the cabin heaters on full and on fan position 2 and the temp guage never went anywhere quarter then i put cardboard on the way home temp got to 80 ish, i am popping down to audi tomorrow will get the craic with the boys hopefully they will shine a light on the problem

cheers Raj

[S2central.net]

Unless there is some other valve or failure scenario that allows coolant to bypass the stat. The car isnt drinking or dropping any coolant. Bit bizarre

[baltiboyS2]

We are all racking our brains some theory thermostat fitted without the rubber seal around the stat itself
aircon on makng the fan run all the time on the rad
faulty temp sensor need to put on vagcom and measure the difference in the engine management sensor and guage sensor no other info im afraid bit of a weird one


cheers Raj