Mk1 Octavia 110 TDI 2002.

Start car up from cold both fans start up. Heating doesnt work well even when engine is 90C, gauge on car sits straight up all time.

With engine on and cold fans start when climate control is on, switch climate to off   the rad fans go off. Blowers push some warm air out max 45C and goes up and down. Done 110k miles belt and water pump think were done.

Changed the fan control unit made no better.

Tried to remove the rad sensor bottom right near battery, cant get plug off it is there a trick. Does this control the fans or the coolant sensor.

Think the head gasket has gone but no smoke yet, thinking the heater matrix might be getting blocked. If rev engine 3000 rpm the top matrix hose gets 75 C and bottom one 45C.

If I take to my garage will the be able to test it whats wrong.

many thanks

Sounds like perfectly normal behaviour for Climatronic in Auto mode to me.

If Climate Control is switched on the fans are supposed to operate all the time. Only when climate is switched off or set to Econ will they go off. Top hose should be hotter than the bottom.

For lack of heat from the heater, my suspects would be, heater motor flap is stuck, blocked heater matrix, air lock, failing water pump, head gasket.

Edited 28 December, 20169 yr by pauldazzle

Mk1 Octavia 110 TDI 2002.

Start car up from cold both fans start up. Heating doesnt work well even when engine is 90C, gauge on car sits straight up all time.

With engine on and cold fans start when climate control is on, switch climate to off the rad fans go off. Blowers push some warm air out max 45C and goes up and down. Done 110k miles belt and water pump think were done.

Changed the fan control unit made no better.

Tried to remove the rad sensor bottom right near battery, cant get plug off it is there a trick. Does this control the fans or the coolant sensor.

Think the head gasket has gone but no smoke yet, thinking the heater matrix might be getting blocked. If rev engine 3000 rpm the top matrix hose gets 75 C and bottom one 45C.

If I take to my garage will the be able to test it whats wrong.

many thanks

The fans running sound normal, I would imagine the reason your not getting hotter air in the car is the thermostat is stuck or partially stuck closed so not allowing full flow of water around the system. I would get it replaced and see if that makes any difference