My 04 focus st170 oil temp has just started going up and down while driving will stay constant at half way when ticking over but while driving goes up and down oil pressure is fine water temp is fine renewed thermostat and housing has anyone had this problem with the st170 and does it have an oil temp sensor if so where is it on the engine never goes above half way but is it affecting the way the car runs

 

there normaly on back of engine mate

 

when was oil last changed as worn/cheap oil can cause this too

 

Fairly sure mine used to go up and down when driving, it's normal don't worry too much. As long as the water temp isn't rising past half way.

 

It will go up and down as when your driving the oil is being pumped around a engine that's also have coolant pumped around the head and block so should keep it a nice temp unless your ragging the shit out of it , sitting there is allowing the oil to get hot hence why cars have cooling fans to cool the coolant which intern cools the oil to a safe constant temperature
Mine does this all the time so I wouldnt worry about

Cheers Paul

 

thanks for your replies i do not have the car any more but i did find out what was wrong with the oil temp.the oil temp gauge is not connected to the oil system it is connected to the water temp so it is not an accurate measure of oil temp.The problem was a faulty thermostat once repaced the oil temp went back to normal