News > News Archive > Beware of Oil Pump Differences

There are several brands of replacement A112 oil pumps available on the market.  I recently ran across a situation where I had a brand new pump made by a major manufacturer, which had abnormally high oil pressure output of 80 PSI at idle.  Even with the oil heated to 200F the pressure was still 75 PSI (5.2 bar).  At 3000 RPM the pressure was again at 80 PSI (5.5 bar).  This indicated to me that the pressure bypass flow was too small.

Pressure this high, particularly at higher RPMs will cause premature wear of the oil pump drive gear and the risk of damage to this gear or even the gear on the camshaft.  Further, this high a pressure could damage main, connecting rod and cam bearings as well.

There is a simple fix for this problem which results in a pump producing 40 PSI (2.7 bar) at idle and around 65 PSI (4.5 bar) pressure at 7500 RPM with the oil at operating temperature.

There are also component differences between the different brands of pumps, and not all parts are interchangeabale.  I have some from two different manufacturers, and the pump rotors are different diameters and have different number of teeth.

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