The service life of engine oil depends on many factors, but cold starts, short runs, dusty environments and towing all affect it. The K9K has a single camshaft, eight valves and a maximum oil service life (according to Renault) of 2 years. 12000 miles is the safer choice.
The turbo is also lubricated by the engine oil and it is cheaper to change the oil frequently, than change the turbo at 70,000 miles.
a) The recommended oil for UK use/ temperatures is synthetic Elf 5W30 or 5W40 ACEA C3. Your Dacia dealer will supply it, or you can use the Renault recommended grades from Castrol or other makers. The Castrol UK recommended oil is EDGE 5W-30 LL or Magnatec 5W-30 C3.
b ) Some owners like to change the engine oil more frequently than 12000 miles, and these interim oil changes can be made through the engine oil filler cap, which on the K9K contains the dipstick tube. You can change the oil filter too, but there will usually be no need until 12000 miles, unless you want to cut the filter open to check for engine wear.
c) A useful interim oil change period is 6 months or six thousand miles. The 3000 mile periods loved by some Americans dates back to the times of older engines, and doesn't have too much relevance for the K9K DPF engine.
d) Dipstick oil suction pumps come in manual and electric types. The cheaper manual ones have plastic tubing which fits down the dipstick tube, others such as Pela, use a 6mm spiral wound metal tube. The metal tubes are slightly easier to use, though plastic tubes can be adapted to take 6mm plastic tubes from aqaurium suppliers. The metal spiral tubes, which look like curtain wire for net curtains, are much easier to use as they provide good feedback when the end of the tube hits the bottom of the sump.
Suction pumps tend to hold 4 litres of used oil, which is about right for a K9K pump-out.
e) First, you'll need an empty container of about 4.5+ litres to take the old oil, and 4.5 litres of the correct oil before you start. A couple of old rags will be needed for the drips.
f) The technique is to warm the engine, then turn it off and wait ten minutes for oil to drain down in to the sump.
Using a dipstick pump
1) The pump tube is gently fed down the dipstick hole until it just touches the bottom of the sump. The engine oil is pumped out with the suction pump until gurgling noises are heard, then the sump is empty.
It takes about five minutes, with gently continuous pumping to keep the oil flow going.
2) If you push the tube too far, it will curl above the oil level, and only air will come out. When the sump is empty, the tube will make a gurgling sound, and flow will stop. If you want to abort the pump out quickly, raise the suction from the dipstick tube.
3) Refill the engine oil with 3.5 litres of fresh oil, then add a little more, slowly, checking the dipstick each time. Don't add more than you have pumped out. Fill to the half way mark on the dipstick, run the engine, let it cool, then check again.
4) Overfilling is bad for some modern engines; it increases crank-case pressure and can lead to foaming, which beats air into the oil, reducing its protection. So take some care when you refill.
5) The old oil is poured into the empty container. Most council refuse-dumps have a used oil tank. You might be able to take the pump bottle to the dump and empty it yourself, but many dumps now insist on checking the container for petrol waste, and ask you to leave the container.
i) This technique does not get out all the old oil as some is left in the oil galleries and oil filter, but will pull out about 4 litres.
ii) It is used very often for marine engines, where there is often no access to the sump drain plug without lifting the engine.
iii) Amazon carries the cheaper Silverline pump, which might need some extra 6mm tubing, or the more expensive Pela pump, which comes with a metal 6mm tube for the dipstick tube.