JoshMaffers

Thank you for the quick responses. I do also fear that it is the head gasket, because of what I have seen on forums. I am going to replace the thermostat Saturday, if the weather holds up. Thank you the instructions, that is a massive help. I will let you know how it goes.

Hello guys, hopefully I have posted this in the right location. I have a Lexus is220d, when driving after about 30 minuets or so, or after high engine revs the temperature gage rises and shows that the car hot. After about 30 seconds it then drops down to the normal temperature again. However after 1-2 hours of driving the temperature then rises and very rarely drops, when it does drop it is only very slightly. When I checked, the engine water had sprayed all over the top of the engine from the water reservoir and there was no water left in the reservoir. Also checking the water that had sprayed on the engine, it is not oily. I am having to top the water up every day, sometimes twice a day. When the temperature is normal the heating in the car works, but when the temperature rises the heating goes cold, even on max temperature. The engine runs perfectly and when opening the oil cap it is not grimy and it is clean. Finally when opening the reservoir cap to fill it, the pressure is being releases causing the reservoir to fill with the water again and spray out of the overflow pipe. I have seen some people mention that it could be the head gasket, however a mechanic mentioned it sounds more like the thermostat, any ideas? I have ordered a thermostat and I will replace that, however I can't find anywhere the actual location of the thermost. All of the guides are for the 250, which is different and it is not in the usual simple location, at the top of the engine. If anyone could point me in the right direction of that, it would be extremely helpful as well!