Now I know this isn't an Aseries based engine but the logics are the same
Part one
The engine has done about 130,000 miles and was from a y plate micra, so 13 odd years old.
During the buying of the car everything engine wise was tested, oil hadn't been changed recently which was evident although researching on the type of oil filter meant it had been changed at least in the last 2 years or so so not that bad
On startup of the engine in the micra, light oil was noted during startup pointing to valve stem seals along with timing chain rattle, both of which resolved once the engine had reached full operating temperature.
On removal of the cam covers no scoring was evident on the cams.
Conclusion the engine although high mileage had no major issues bar valve stem seals on the way out.
Part two.
Engine was removed from micra and fitted to mini, welded inlet manifold fitted to cylinder head using instant gasket to test ignition etc. engine ran fine but oil was seen coming from all four cylinders, engine never reached full operating temperature during this test as no exhaust or coolent system fitted
Conclusion, valve stem seals gone.
Part three
Engine taken apart, valve stem seals changed and valves relapped in, no scoring on valves evident and all sealed to an equal level with the petrol valve seal test. New headgasket fitted. On examination of the inlet manifold the oil substance seen coming from cylinders was a mix of instant gasket and petrol from carb over fuelling. Engine was found to taken apart for no reason due to me being a muppet, valves lapped in and stem seals changed, engine should now be in good workable condition. Engine filled with castrol gtx fully synthetic 5w40 as recommend by micra sport club as best for the car. Engine tested, no puffs of smoke from valve stems.
Conclusion engine sorted
Part 4
Cylinder head removed to change head gasket as on previous build up part of the gasket was caught leading to major oil leak on engine running. That all went fine and oil leak has now ceased. Engine topped up with oil from my garage again 5w40 like before, tesco make not castrol (was on the side from a previous car).
Conclusion everything should be finally hunky Dorey
Part 5
Well it's not. On engine reaching full operating temperature it's pissing out oil enough to give a hell of a shiny coating on the gravel drive
Video attached
http://i1111.photobu...1029_171146.mp4
So my conclusion is oil control rings as there seems to be no issue with the engines compression that I can tell of
Exhaust manifold removed
Cylinders 1-3 clean if running slightly rich
Cylinder 4 pissing oil like no tommorow
, So piston 4 has leaky oil control rings It then catches my eye that 5w40 fully synthetic is not what the manufacturer recommends for the micra k11. The recommendation is 10w40 part synthetic.
Therefore I come to the conclusion that the car has worn oil control rings that are causing oil to burn once the engine has got to temperature as I have fitted a lower oil viscosity than recommended.
My plan is to add some oil fortifyer to up the viscosity of the oil to prevent oil burning. If this proves successful drain the engine and fit good quality but higher viscosity oil than recommended.
What are peoples opinions on this idea
I apologise for the essay but wanted to add some background to this issue
Many thanks
Lawrence
Edited by lawrence, 05 November 2014 - 02:59 PM.
