I've noticed today that my oil pressure gauge shoots straight to 3 on ignition, before the engine even turns over, so I guess it's a faulty sender unit. Where are these located and is it an easy job? The cars under warranty, but its a case of seeing if this is covered and then going back and getting it done as the car was bought from quite a few miles away.

Also the engine runs on temp 80 but it goes up and returns so the thermostat seems to be working okay, and the top hose is hot and the bottoms cold as it should be.

It’s just had a main dealer service and the engines dry and quiet so I’m not too worried. But my old W123 230CE temp was always around the third mark and my C180 ran much hotter and it’s got the same type engine?