Is this a head gasket failure? I am wondering if LR3 have the issue where the coolant temp sensor is not accurate if the thermostat gets stuck.

I have a V8 LR3, it ran low on coolant until the heater stopped working. The dashboard gauge never showed any signs of overheating and the car drove home fine. The only odd thing is the car would surge a bit when doing 2-1 gear downshift. My guess is the thermostat got stuck or there was an air pocket in the cooling system. However, I have noticed white smoke from the exhaust that emits a few minutes after the car is started. Its a similar amount to when the car is started on a cold day but it doesn't go away even after 15 minutes. The oil is fine, no milky color.

 

Does it run rough on a cold start? Usually, when the headgasket is blown and you are burning coolant, it will misfire. At least all the ones I have seen. Headgaskets on these are not common, but can happen if run hot enough. Are you having to add coolant? You can try a "block test" (chemical test which checks for combustion gasses in coolant), but I have found them to be less effective on vehicles with expansion tanks (like Rovers and BMW) vs vehicles with a radiator fill neck. Most decent parts stores sell the Block Test.

 

I posit since you ran the coolant low, air may be in the coolant passages. Did you bleed the air out when you filled back up?

 

It starts and runs fine, only thing is the white smoke from the exhaust. I'll have to try the block test, thanks for the suggestion!

 

Yeah coolant is fine now but it's the exhaust that has me worried.

 

I have an lr3 2006 replaced thermostat cover and water pump now Runs hot and leaks from the bottom... Did I blow a gasket too, could it be something else

 

Did you hook the electrics back up on the fan?

 

I will ask my mechanic about the electronics on the fan... It leaks now from underneath the front on the drivers side. It was not doing this until I changed the water pump.