Aud1 a4 2005.heater blows cold all the time

Try removing the thermostat and reverse flushing the motor, Actually try flushing in both directions, this will tell you if you have a circulation problem but 1 thing you should know is that the water goes in the water pump and out the thermostat, try running it without the thermostat and check your water flow

If the coolant temp gauge is in it;s usual position when driving(at least 1/3 way up) then flush the heater core with a garden hose.Clamp off the heater hoses,remove them from the heater core and flush back and forth a few times until flow is good,reattach heater hoses and you should have heat as long as the heat/cold airflow door is in the heat position in the heater assembly under the dash.

sounds like you may need to replace the thermostat and also check fluid level....hope this helps ....good luck

1. if your thermostat is going out...you will generally over heat if its stuck in the closed position....initially you might not even notice.but watch your temp gage.

2. If sticking in the open position..rare... your car will require a longer warm up period...operating temp.....heater takes longer to heat up...tough to check in the summer time...if you think its going out then just replace it and be sure to install the new gasket that should come with it....they are cheap and one of the easiest things to fix on a motor...failure to fix it can result in an overheated engine, oil breakdown and seized engine parts

3. Water Pump.
Listen for a faint ( initially ) metal on metal sound from the front of your motor.... easiest thing is to take a cut off broom handle...solid wood....place it on a section of the pump where you won't get hit by the belt or fan blade...then place the stick against your ear and listen...you will hear a faint smooth grinding sound...thats the bearings...if its chattering or very loud, then you have a pump going bad...also just before they go out you should see water dripping from the bottom of the pump or engine, near the pumps location.
You can buy stethoscopes and use water hose etc to check it but the wooden handle is the cheapest.

It should be 200 degrees. If your running cold the only thing that regulates temp is the thermostat. If it is indeed 150 degrees thats why you have no heat.

If you replaced the water pump and the radiator for this condition then it was a waste of money. If you had a water pump or radiator problem it would overheat.

The fact that your blowing cold air tells me the that you really are 150 degrees or the heater core is plugged.

It's possible you have a bad vaccum line to the actuator door in the heater assembly
or possibly a stuck thermostat

Hi there,
firstly why did you replace the water pump, would i be correct in thinking that it broke, if so, when you took it out was there damage to the impellor, usually there is and these bits of debris have to be retreived. the hot air in your car comes from a heater matrix that is seperate to the main radiator the cause of your problem could be explained by loose debris blocking the heater matrix inlet, also that debris could fall back down and destroy the impellor on the new pump.
If the impellor completely broke up then it will be debris in the system this should be fixed asap to safeguard the new pump.

sounds like the thermostat is not functioning correctly? either that or not in at all? thus making the water which would normally warm up quickly, warm up extremely slowly and on really cold days not at all? with a 2.6 engine your car shoudl warm up in record time?

dont get many faults with heater matrix in 51 plate golfs,but its a very common fault you have........the water pump impellor breaks up and dont move the water round the system,and the system is self bleeding..

Sounds like a thermostat sticking. Some things to do. First check coolant level is up and moving. Second (most likely), change thermostat. Very easy fix for backyard mechanic. Make sure to put thermostat in so water flow is correct direction. Look for arrow on side of thermostat. Next, is belt to water pump loose. Another easy fix in most cars.