2008diesel navara oil leaking from the exhaust muffler and blowing white smoke

White Smoke = Steam
Blue Smoke = Oil
Black Smoke = Rich Mixture

Are you losing coolant?

Are you losing oil?

And my learned colleagues excellent advice should be down here.

Have you opened the bonnet up and looked at engine ?
Suggest checking oil cap is screwed on properly ?
Look at exhaust manifold is there oil spilling onto it ?
check oil dip stick is fully inserted into engine ?
Also check power steering pipes for leaks ?
Let us know how you get on !!

Sounds like a blown head gasket or cracked head

Causes of White Exhaust Smoke

White smoke out of the exhaust indicates moisture (water) in the exhaust. If the car is not driven very far each day, some moisture will collect in the muffler and cause white smoke for a short while after starting. If the smoke is continual, however, you need to watch you coolant level as you may have a blown head gasket.

Blue smoke is oil. Compression check. and check plugs for fouling.

IF LOT WHITE SMOKE KEEP COMING OUT OF EXHAUST PIPES YOU HAVE LEAKING HEAD GASKET.CHECK ENGINE OIL.LOOK AT DIP STICK.IF OIL LOOKS LIKE MILK SHAKE ON DIP STICK ANTIFREEZE LEAKING INTO OIL CRANK CASE.

THIS IS NORMAL IF IN COLD WEATHER BUT IF YOU HAVE WHITE ALL THE TIME YOU MAY HAVE A COOLANT LEAK WITHIN THE ENGINE.THE WAY TO TELL IS TO TAKE THE RADIATOR CAP OFF,BUT MAKE SURE THE ENGINE IS COOL,AND CRANK IT UP,IF WATER STARTS PUSHING OUT THEN ITS A HEAD OR GASKET PROBLUM WITH THE MOTOR

take it back the engine has a blown head gasket or cracked head all cost over 1200 to fix

This is usually an indication of a bad head gasket.I gasket. The white smoke is the coolant leaking out of the engine and winding up in the oil passages, due to a bad head gasket. To confirm this,
1. check oil. Is level increased, or milky appearance?
2. Is coolant level dropping, but u don't see any signs of leaks?
The above indicates a bad head gasket, causing the white smoke u describe. Let me know how u make out.

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White smoke is caused by coolant or water coming out the tail pipe. There is a chance that the white smoke was caused by water splashing up from a puddle onto the exhaust pipe. Keep an eye on the coolant level in the radiator in any event. If its less then there leak coolant leak in the car engine which is causing this problem....