Engine overheat warning and no heating

[Jamie Marples]

Good Evening all,

Just putting it out there as I've searched and searched with no luck and would really like to know if any one has had the same issue or has any knowledge of this.

I have a 2013 Q7 3.0 TDI is done just over 100k.

 The car warns me of high engine temp and the gage reads 130'c, i can stop the car then re-start and the gage will go down.

The rad pipes feel warm but not overheating temperature (touchable) and there is no leaks of coolant. the fans kick in as normal when the engine left running for a prolonged period and also when the temp warning is active.

I have swapped the whole thermostat and housing along with a new water pump and new coolant.

The other issue is the heating is very intermittent with temperature. I can hear the heating unit through the dash making noises like a valve/motor operating unsure if this is normal as i expect noise when the heating is being altered and flaps changing and so on but not constantly. 

Could the heating issue be the sole cause of the engine temp warning or is this something as easy as the temperature sensors being inconsistent and then throwing the heating out?

I have read on various threads that the car is fitted with two sensors is this correct?

thanks for any help really struggling with this and i have a large drive due next week and don't fancy a journey on a recovery truck!

[skittisher]

Hi,

Have sorted the issue?

 

Had exactly same issue on the way home today.

Pipe near thermostat was worm. Near bottom of the engine hot. Engine itself felt normaly hot.

Collant tank was at a normal level and worm. And for aome reason no high preasure it ahould be when engine is overheating, colant pipes were soft and could be squeezed easily.

All above indicate stuck close thermostat which was taken out so to get home.

Coolant was topped up and strangly temperature stayed at 90deg for nearly 20miles of driving then fell (finally!) to approx 75 deg and stayed at at this level until home was reached after around 100 miles. I was accelerating slowly and drove mainly on motorways.

Water pump seems to be working as idicated by pressure teater.

Not sure why there was no preasure in cooling system if engine was overheating, pipes should be stiff and hard to press even at normal operating temperature.  Secondly both radiators fans kept running on full speed even if engine temperature as per gauge was 90deg.

Will replace the thermostat and fingers crossed it will be ok.