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Why oil psi ought to be monitored

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by vmaxer, Jul 9, 2011.

  1. Reasons why oil pressure should be measured on expensive engines

    1 - Most modern computer controlled engines do not monitor oil pressure. They use oil temperature feedback to assist in adjustment of the fuel/air mixture to the injectors. Does overtemp on the oil temperature eventually also lead to the computer shutting down the engine ????? Or will the engine keep running if the oil pressure is low but not low enough to de-activate the pressure switch and the oil temp does not climb high ?????

    2 - Most oil pressure switches operate at extremely low psi, in the order of 2 - 5 psi (or 0.2 - 0.3 Bar).

    3 - If your engine runs on open road use at 30 - 60 psi and something blocks or fails but you still run continue to run at say 5 - 10 psi, you run the risk of engine metal wear and or serious damage. The pressure switch is still activated, ie no warning and you continue to ride not knowing there is a problem in the sump.

    Now let's look at the reasons for oil pressure loss:

    A - Any component manufacturer knows about the "bathtub" reliability or failure curve. Well it applies also to oil filters, they can be faulty, if they are blocked for whatever reason and the internal bypass valve does not open completely you will have a very large drop in oil psi. Filters are only batch tested, not individually.

    B - If your engine oil is or was neglected over time and gunk builds up covering the stainless steel mesh on the oil pump intake, psi will be reduced. If your lucky the psi will be so low it de-activates the pressure switch and the computer shuts down the engine. If you are unlucky you could be running with low psi. Buying a used engine is a risky business !

    C - The oil pump could be faulty, ie relieving at low psi levels.

    It really strikes me as odd that new computer controlled engines monitor virtually everything but oil psi ? The level of sophistication on the control system is quite mindboggling, yet they leave out the oil psi ? Sensors and transducers are so cheap today, so it's not been done for cost reasons and writing extra software for a computer chip would not break the bank.

    Even the BMW R1200 with it's German ingenuity omits to monitor oil psi and opts for 2 x cylinder head temp sensors, 1 x oil temp sensor & 1 x oil pressure switch ? The GSX1400 computer only monitors oil temperature and possibly uses the feedback only to adjust the fuel mixture ?

    If your engine is old fed from Carbies then quite possibly you have only the pressure switch and an oil warning light to rely on.

    Personally for me I fit an oil pressure gauge to any expensive M/C motor, bitten by past experience of disasters, I like to have peace of mind with what's going on in my sump.

    Vmaxer @ http://ozmcripoff.webs.com/