Heater Issue

[niftyandy]

Hi guys
Got a problem with my heater in that it seems to now only blows out either cool or very luke-warm air. The luke warm air arrives after about 30mins of driving, though the heater fan kicks in ok after 3mins or so as usual when set to 'Auto' with 25'c set on the display. Car is getting up to temp ok - sits at 90'c all day long so thats ok, so I dont think its a thermostat issue and the car drives fine.
If i drive for a while, say on the motorway, then air gets a bit warmer but not overly so and when i stop at lights or into slower traffic the air from the blower goes colder again. The blower is trying to blow air but its just cold ot cool even though system is set to 'HI' or whatever warm setting I use.

Any ideas...?

If its the heater matrix blocked, as Ive read on some threads, is it relatively easy for a garage to flush it through? (as id rather not buy a replacement!)
Probably mean a complete coolant system flush etc eh?
Cheers for any info
Andy

 

[AU01 A4]

does it ever go past 90 on the temp, when you drive it hard. if it does it could be your water pump

 

[niftyandy]

Hi
No, whatever I do it stays solidly at 90c, which is good so think the pump is ok...thinking maybe thermostat might be stuck closed (as well as heather maybe blocked).
Could the thermostat be the culprit too?

 

[donsajid]

i think you need to check if you have water circulation. If you do then that should rule out thermostat and water pump.
Best way is to remove the inlet pipe in to the coolant res and start the car, wait 2 seconds and switch off the car again. If no water then this could be waterpump or thermostat. Another check is to see if both pipes coming off the rad are hot, if only one is hot and not the other, then it would point to a circulation problem i.e thermostat or waterpump