Car heater

[Slashmb]

Quick questions about the cabin heater in my car.

Would you expect it to have warmed up after 12 miles driving?

What about if the thermostat was stuck open?

It was only just taking the chill off after 12 miles. Roads were an even split between 30, 40 and 50 mph and the car is a 1.6 turbo petrol.

Can't say I've ever noticed it taking this long before.

Thanks

[Baryonyx]

Yes, the water in the system should heat fairly quickly. After 12 miles, I'd suspect a fault in the heating circuit, probably a sticking thermostat like you say but possibly HGF! A mate of mine recently picked up a used Nissan Navara which wouldn't give heat whilst driving and it was traced back to a failing head gasket.

[ianwayne]

Are you sure it's not low on coolant? If it's lost or leaked some, there may not be enough circulating to reach the heater matrix. Rapid rises and falls in indicated coolant temperature usually happens if this is the case too.

[iva cosworth]

I'd expect the heater to be hot after 1/2 of your 12 miles.

If the thermostat is stuck open it might never get hot unless in heavy traffic.

[Slashmb]

ianwayne said:

Are you sure it's not low on coolant? If it's lost or leaked some, there may not be enough circulating to reach the heater matrix. Rapid rises and falls in indicated coolant temperature usually happens if this is the case too.

Never thought of that. I'll go check now.

[Slashmb]

Feel stupid now...

It took about 800ml to top it up but then I noticed a drip from underneath and a small pool on the drive.

I'll ring my mechanic tomorrow...

Thanks for your replies chaps.