Engine overheating Audi A3

Hi,

Engine is overheating coolant level is normal, if I turn on the heat
in the car all I get is cold air ???. Noticed that if I open the
coolant/expansion tank and leave loose and run the engine. indicator
for engine tempature stays normal and I ahave heat if I turn back on
the heating.

Anyone anyideas.

Thanks in advance

> wrote in message
...
> Hi,
>
> Engine is overheating coolant level is normal, if I turn on the heat
> in the car all I get is cold air ???. Noticed that if I open the
> coolant/expansion tank and leave loose and run the engine. indicator
> for engine tempature stays normal and I ahave heat if I turn back on
> the heating.
>
> Anyone anyideas.
>
> Thanks in advance

the water pump continually forces water around the system diverting it
(short cut) when the thermostat opens and closes. Cooling being carried out
by fans and temperature sensors.

Thermostat faulty
Radiator blocked
Fan faulty
Airlock in system
Expansion cap faulty...........could well be this.

In article
>,
wrote:

> Hi,
>
> Engine is overheating coolant level is normal, if I turn on the heat
> in the car all I get is cold air ???. Noticed that if I open the
> coolant/expansion tank and leave loose and run the engine. indicator
> for engine tempature stays normal and I ahave heat if I turn back on
> the heating.
>
> Anyone anyideas.
>
> Thanks in advance

Maybe the radiator cap has gone bad. A failed inner seal causes the
coolant to boil during hard acceleration. A failed outer seal causes
air to be sucked in when the car cools.

Kevin McMurtrie wrote:
> In article
> >,
> wrote:
>
>> Hi,
>>
>> Engine is overheating coolant level is normal, if I turn on the heat
>> in the car all I get is cold air ???. Noticed that if I open the
>> coolant/expansion tank and leave loose and run the engine. indicator
>> for engine tempature stays normal and I ahave heat if I turn back on
>> the heating.
>>
>> Anyone anyideas.
>>
>> Thanks in advance
>
> Maybe the radiator cap has gone bad. A failed inner seal causes the
> coolant to boil during hard acceleration. A failed outer seal causes
> air to be sucked in when the car cools.

Check also the water pump impellor, depending on the age of the A3 some
of the earlier ones (1997-) had plastic ones. During a particularly
cold winter, the plastic fins snapped off on mine and this caused the
car to overheat.

Not sure whether the fact that opening the expansion tank fixes the
problem negates this theory however.