The True Cause of an Over-Pressurization Condition in Your Vehicle
A blown gasket or a deformed filter canister in your vehicle are symptoms of over-pressurization. The oil filter is often blamed for this condition; but it’s not the true culprit. The actual root of this problem with oil pressure is due to a malfunction within the oil pump.
Most vehicles have a pressure-regulating valve with a plunger/ball and a calibrated spring tension built in the oil pump. This valve maintains the oil pressure within a given PSI range determined by the vehicle manufacturer. Pressurization problems pop up when the plunger sticks in the bore in which it travels. If the plunger sticks in the closed position, an over-pressurization condition will occur. If the plunger sticks in the open position, a loss of oil pressure will occur.
Here are a few things that promote sticking pressure regulating valves:
- Plunger or bore wear
- Imperfection in the valve bore
- Sludge deposits due to poor maintenance schedule
- Debris, restricting plunger travel
- Metal fragments from machining or bearing wear
- Removing gaskets with an abrasive disc that produces fine grit
- A damaged or improperly sealed air filter can allow dust and debris to enter the combustion chambers and eventually into the crankcase
Also, if the O-ring that seals the pick-up tube to the oil pump fails to properly seal, a low, no, or fluctuating oil pressure condition may be the result.
Oil filter flow rates for the newer engines result in a higher-pressure differential across the filter media. This requires a higher bypass valve setting. Filters that are not manufactured to these specs will result in unfiltered oil flowing through the engine causing major internal damage and oil pump failure.
This is why it is crucial to select and know the quality of filter in your vehicle. Failure to install an extended life oil filter on vehicles driven for extended mileage between servicing, for example, can promote premature engine/component failure. Conventional filters will not provide sufficient filtration for extended service intervals, allowing filter by-pass to occur.