Ford focus 1.6 tdci engine management light has come on water temp crept up slowly but dropped when heater switched on any ideas?

Hi Lee,could be a bad thermostat not opening fully,or a bad bearing in your water pump causing antifreeze not to recirculate properly,or your radiator is clogged and needs blown out.

sure , read the FSM.
go to Ford, , parts counter and buy the Factory service manual.
on my car 08 , its on CD and is 7000 pages. long.
make sure its covers the Diesel option.
some (many) makers of cars, alternate engine options have
SUPPLEMENTS. ask em'
what country are you in, or where was car sold to.
see the diagnostic pages for your DTC errors and all tests to do.

second gen, Focus engine; line up, WHICH ONE>?

1.4 L I4 Zetec-SE
1.6 L I4 Zetec-SE
1.6 L I4 Zetec-SE Ti-VCT
1.6 L I4 Diesel TDCI
1.6 L I4 Diesel TDCI DPF
1.8 L I4 Duratec HE
1.8 L I4 Diesel TDCI
1.8 L I4 Duratec HE FFV (Flexifuel vehicle)
2.0 L I4 Duratec HE
2.0 L I4 Diesel TDCI
2.5 L I5 Turbocharged T

diagnosing any engine.
step 1 is engine
and step 2 is blown fuses.
and step 3 is read the TSBs on your car. (tech .serv. bul)

you need to have the check engine light repaired first most likely related to heat and or gas issue and a check engine light is not a 1 issue thing code will need to be pulled if you have a autozone they can pull it for free and theres where we need to start .could be anything from o2 sensor to a thermostat ect...

Am sure you have a thermostat stuck open, i suggest replace it and make sure the aantifreeze is in the correct level.

There is no such thing as a fuel injector shut off switch. The fuel injectors are controlled by the camshaft position sensor and other engine management components.

interior engine problem most probably head gasket, sorry

hi the cabin/pollen filter is usually accessed behind the passenger drop down glove compartment adjacent to the heater assy best to remove the drop glove compartment to ease access

abs sensors on brakes need replacing eml should go off when abs problem resolved

This is normal for a car that has an electric fan system for the cooling system. There is a sensor that operates based on engine temp. When you turn your vehicle off the coolant stops flowing and the water temp goes up in the engine block. The electric fan may run for approximately two or so minutes.

better left to mechanic not easy to do