Hi guys I have a coolant problem my 300 tdi shows some leaking from the P gasket but I lost about 1/4 pint of coolant when I stopped out side home. it took a kettle of water about 1.7 Ltr butt decided to look further took of big brass nut from thermostat housing not very much coolant that side topped it up see how it goes looked on RAVE coudnt find any mention of P gasket in cooling section and why are there two electric senders under the thermostat housing.