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MG MGF Technical - Oil Consumption

My mgtf gives a big puff of Blue smoke on starting when the car has been standing for half an hour or longer. Otherwise it starts and runs well with no trace of smoke from the exhaust. However the oil consumption is high going from top of the dipstick to the bottom in about 1500 miles.

I believe that valve guide seal wear is likely to cause the smoke problem but would that also cause such an excessive oil use?

The car has done 65K and the previous owner said that it had new piston rings about 10k ago when the head gasket was replaced.
M.E. Prior

Although there may not be visible smoke, if a valve guide seal has failed it will be letting oil into the combustion chamber fairly constantly, so a 1 litre drop in 1500 miles isn't unlikely. It is possible it's not all going that route though, is there any evidence of a leak elsewhere, i.e. oil collecting on the sump?
bandit

The sump looks clean and there is no evidence of oil drips on my garage floor.

mick
M.E. Prior

Replacement of the piston rings following a Head gasket failure indicates pretty heavy secondary damage that is not the normal.
There must have been an indication that the rings needed replacing ie. a seized engine or scoring/damage of the bores which may require further investigation.
Geoff F.
Geoff Farthing

Very rare for a K-series to do this at this mileage - which either means that oil is leaking outside, but burning off on exhaust manifolds, or as has been already suggested, burning off inside the engine, indicating valve stems etc etc....

If the latter, then its rebuild time, or replacement (may be cheaper, if good engine purchased second hand)
Rob Bell

This thread was discussed between 30/11/2009 and 07/12/2009

MG MGF Technical index

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