I have a 2005 Focus ZXW. it's ran like a dream for the past few years. she only has 81,000 km on her.

Last week she started acting strange. it would become sluggish when I stepped on the gas. almost stall in some cases.

Now, she won't stay running. If I can get it to start, it chugs like it's running out of gas and stalls. Also, seconds after starting the temperature gauge goes to maximum and the fans come on. even though the engine is not hot. ( can rest my hand on the manifold while it's claiming it's hot.

a couple people have suggested a few problems. Air lock in the cooling system. blockage in the heater core. a broken sensor. or worst of all, a blown head gasket.

any help is welcome. such as, where is the sensor for this located. where can I find part numbers to look up replacements?

Thanks in advance