BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason

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Mon 23 Sep 2013 17:38
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - Wild Oat

I have had this car from new. It now has about 113000 miles on the clock . In the last few thousand miles oil consumption has become every high - about 1 litre per 800 miles.

Servicing has always been on time /early and only BMW recommended oils have been used

It is not showing any smoke so I presume that it is not burning the oil through poor piston rings or valve stem seals.

There are no signs whatsoever of any oil leakage either below the car or from the oil-filler cap.

I am at a loss to explain the oil useage or how to correct it economically. I have experieced BMW main dealers with their "highly-trained technicians" and am not impressed. I suspect all that they would provide would be a large bill, with little satisfaction, so I am not inclined to approach them.

It has been suggested to me that the problem could be with a failed "Cyclone Valve". I have never heard of a Cyclone Valve nor where it is or what it does .

Does anyone have any suggestions on this problem or information on Cyclone Valves

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Mon 23 Sep 2013 18:44
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - unthrottled

It's probably part of the oil separation process of the crankcase ventilation system. Essentially crankcase vapours are vented to the inlet manifold-hopefully without engine oil. If this fails oil vapour could pass straight into the inlet manifold and be burned up that way.

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Mon 23 Sep 2013 19:10
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - madf

It's probably part of the oil separation process of the crankcase ventilation system. Essentially crankcase vapours are vented to the inlet manifold-hopefully without engine oil. If this fails oil vapour could pass straight into the inlet manifold and be burned up that way.

Or the entire system has become pressurised...blwoing oil straight into teh manifold.

A cat will burn off small quantities of oil and leave little blue smoke...

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Tue 24 Sep 2013 09:08
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - elekie&a/c doctor

The cyclone valve is indeed part of the crankcase ventilation system and is located under the inlet manifold.However when these fail,there is a noticable uneven engine idle and often slight "hunting" of the engine as excees air is being drawn in.hth

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Tue 24 Sep 2013 15:15
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - Wild Oat

Thanks for the info.

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Tue 24 Sep 2013 15:13
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - Wild Oat

It's probably part of the oil separation process of the crankcase ventilation system. Essentially crankcase vapours are vented to the inlet manifold-hopefully without engine oil. If this fails oil vapour could pass straight into the inlet manifold and be burned up that way.

Or the entire system has become pressurised...blwoing oil straight into teh manifold.

A cat will burn off small quantities of oil and leave little blue smoke...

Thaks for the extra info following your initial reply

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Tue 24 Sep 2013 15:12
BMW 325i Touring Dec 2001 registration - Excessive oil useage with no apparent reason - Wild Oat

Thanks for the info

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