Oil became milky in rover 200 - GMC Cars & Trucks

Head or intake gasket leaking. Is the coolant milky? Or do you just see a little oil in the colant? If it's not milky i would not worry. If it's milky ,To buy you some time add some bars leak into the radiator. Then change the oil and antifreeze.

Milky oil indicates coolant is getting into the oil . These engines are know for intake manifold gasket problems .

Look close for oil leak from your valve cover on the exhaust.
check coolant with cold engine and top to max. next day recheck if yore losing coolant

Have you checked your oil level? Is it over full on the dipstick? What does the oil look like - clear or milky? If milky, you may have had a head gasket failure or crack in the block/head that allowed coolant into the crankcase. If you kept running the engine after this, it may very well have seized. The timing chain can't get 'too tight', so that is not your problem.
Use a breaker bar with the appropriate sized socket and see if you can manually rotate the crankshaft pulley. If not, your engine is going to need some serious work (or replacement).

milky oil is antifreeze got in,,head gaskets going internal,,ck coolant to see if u lost any

Yet--Hopefully

Head Gasket
Intake Gasket
Water Pump & drying off so you don't see it

Milky oil usually indicates a leaking head gasket which is allowing coolant and oil to mix. How does your collant look?

Milky oil is usually a sign of coolant getting into the oil and this is either through a leaking cylinder head gasket or a cracked head or block. Get this attended to before using the vehicle again. You could still save the bearings and rings. Pull the head/s first and check the gasket, that is the most likely cause of the problem.

milky oil in commodore enigine or any engine is the sign off leaking head gaskets or cracked cylinder heads and the coolant and oil are mixing which is the cause of the milky coloured oil

You do not say if it is a manual or auto.

Manual - The level fill plug is left hand side looking up at the gear box from underneath on your back, head at the engine end. Undo on level ground or a ramp if possible. You will need a imperial socket/spanner set.
When you undo the upper plug, which is about the middle of the box, you should find a clear red oil in side, is just below the thread level. You will not see this so use a pencil as a dip stick, only putting in an inch, do not let go of it, and if you find that the level is low check seals. If less than 1/4 inch don't worry.

Top as needed with gear box oil see owners hand book, or your local autostore. If if brown or milky coff coloured it is in need of replacement and any problems such as water ingress will need to be identified.

Autos is easy, dip stick in the engine bay up by the bulk head......though you will need to run the engine at some stage of checking this, and use you hand brake, engine in neutral. There is an oil filler tube to top to amke life a bit easier.

Get a service manual or book or try http://www.landroverweb.com/Land-Rover-Range-Rover-manual-pdf.htm

Charlie @ http://www.theoffroadstore.co.uk/