Renault Megane - smoking engine

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Mon 31 Jan 2011 17:49
Renault Megane - smoking engine - kwakman

I have an 1.9 diesel with 68000 on the clock and the car is blowng oil. It is worse at start up and is less when the engine is hot, it is white smoke and smells more of diesel than engine oil. The car drives well but is not 100% smooth. Can you throw any light on this issue please, i would not expect an engine with only 68000 miles to be blowing oil out at all. my logic tells me it is unburnt fuel for whatever reason. hope to here from you soon many thanks

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Mon 31 Jan 2011 22:49
Renault Megane - smoking engine - Peter.N.

White smoke is caused by unburnt fuel, if it only does it on start up it could be one or more glow plugs, if it does it all the time and the engine runs unevenly, could be low compression one one or more cylinder, unlikely to be due to wear at that mileage but could be reduced valve clearances. Another possibility is air getting into the fuel system but that usually causes difficult starting.

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Tue 1 Feb 2011 00:10
Renault Megane - smoking engine - kwakman
many thanks for your comments, i will use these for further investication, i was just wondering is the valve clearance adjustment would be a straight forward and routine operation on these cars and i will probably replace the glow plugs as a matter of course, thanks again.
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Tue 1 Feb 2011 03:36
Renault Megane - smoking engine - unthrottled

is it the IDI engine or a DI engine? The cold start behaviour of the two engines is quite different.

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Tue 1 Feb 2011 10:03
Renault Megane - smoking engine - Peter.N.

I wondered that but replied on the basis that it was an IDI. I don't know this engine but I expect as with most others the valves are shimmed which doesn't make it a particularly easy job to adjust them.

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Tue 1 Feb 2011 12:48
Renault Megane - smoking engine - unthrottled

True, but valve train clearances tend to get bigger with age-unless valve seat recession comes into play.

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Tue 1 Feb 2011 22:50
Renault Megane - smoking engine - Peter.N.

Possibly on this car, most of my experience has been with PSA XUD engines and they tend to close up with age likely due to 'pocketing'.

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