sharjeelpk

Hello Everyone, I am new to this forum and Audi world. I bought 2008 Q7 3.0 TDi Q S Line from Car Auction in London ,When I was driving it back from Auction I noticed that heater is not working and temp needle is also not going up even after driving it more than 100 miles, I stopped on services to check the water , water was full in water tank but it was cold after good 150 miles on motorway. There was no warm air/ No Heat and temp needle does not go up at all. Needle stays at the lowest point 50. Showed it to my mechanic and he said it is Thermostat so put new Thermostat, but problem is still there, some time in local drive needle slightly goes up but never hit the mid point where I think it should stay, when needle go up I can feel slightly warm air, another thing is Not enough air coming out of the Air vents, I changed the carbon pollen filter but no change.
Any help would be great , Thanks In advance

dreadlocks

clogged heater core?

sharjeelpk

And Can I sort that out ?

dreadlocks

test by finding the two coolant hoses going though the firewall into the cabin, one is input and the other is output.. they should not be more than 4-5 degrees off from eachother.. if one side is hot and the other side cold, its clogged.. its not too terrible to replace, you can get to it from under the dash IIRC.

Could also be a failed water pump or a clog somewhere else, feel all the coolant hoses and make sure you dont have one boiling hot somewhere.. I'd stop driving it til you figure it out, with no coolant flowing through engine your setting your self up for a catastrophic failure.

sharjeelpk

I booked the car again for complete coolant flush to make sure there is no ari trap I will tell mechanic to check the heater core as well. I already spent £150 on it for thermostat . I was driving it today local and temperature was much better and air from heater was warm, It was not enough tho . what do u think why not enough air from vent . when I was putting new pollen filter I noticed that there was not any filter there , it was empty . please also advise me on the following
I want to do things in following order

1- Fully flushed coolant and bleed it
2 - heater core clean
3 - water pump check or may be replace

do you think I should do something else or missed something or do it in different order

Thanks Agian

dreadlocks

make sure they put the proper G12 coolant back in, you cant really clean a heater core.. if it wont flush its gotta be replaced.. bleeding the system is a total PITA, I'd go to a shop that knows what they are doing and not your corner service station.

sharjeelpk

Thanks Mate, mechanic said he found couple of blocage which he cleared but problem is still there , gets very cold when i drive over 30mph but start getting some warm air and gauge goes up slightly if I stuck in traffic or red lights , Now he said car need a new water pump. so booked it to replace water pump.
What I do not understand is , if water pump is dodgy then it should not be pumping water in engine, in a result engine should overheat but it is not overheating. in fact when I drive fast it gets cooler.
I dont know where are you from but I am struggling to find any Audi specialist in my area, I am bradford now.

sharjeelpk

Ok, I have done everything, cant fix the heating issue, Now planning to change engine coolant temperature sensor. at the moment I dont not know where the sensor is located in my 2008 Q7 . Any Idea ?

AddyA6

Did you manage to solve this? I have the same problem.... Thx!