Term used to describe the damage in a filter whose appearance shows a crushing of the central support for the filter element (Figure 1).

When we find a filter element where a collapse has occurred, the natural tendency is to think that something in the filter did not work correctly, this being the cause of the damage. Generally this is not the cause of the damage, but the symptom of a problem in the engine.

 

figura_1Internal combustion engines have a relief valve between the inlet and outlet of the total oil flow, this valve allows continuous lubrication creating a bypass through which the oil flows without passing through the filter directly into the engine when there is a significant restriction in the oil pressure, due to the saturation of the filter or cold start (figure 2).

Generally engine manufacturers have designed these relief valves to open when the differential pressure exceeds 10 PSI; others use pressures up to 30 PSI. Thus, some engine manufacturers design this valve integrated in the monoblock, while others prefer the filter to carry it.

Automotive filters are designed to withstand significantly higher pressures than the normal operating pressure of work without collapsing, hence when a filter collapses; it is usually the result of an obstruction and malfunction of the relief valve.

figura_2Sometimes the obstruction of the valve is not enough to collapse the filter. The pressure regulating valve can also become clogged resulting in a pressure increase in the flow through the filter, although this condition can be temporary, quickly can collapse the filter if the relief valve cannot release the pressure excess due to the sudden change above the normal working operation.

A collapsed filter can cause loss of filtration and engine lubrication, if this condition occurs, the pressure regulating valve and relief valve should be replaced by new ones as soon as possible, thereby preventing further damage.

The malfunction of the relief valve and pressure regulating valve and the subsequent collapse of the filter, cannot cause significant damage to the engine, but sometimes have catastrophic results, often resulting in serious overheating and even damage to the rods due to lack of lubrication.

Common causes for the malfunction of both the pressure regulator valve and the relief valve can be:

  1. Sticky surfaces caused by cold start or use of highly viscous oil.
  2. Excessively contaminated oil associated with condensation, refrigerant mixture and oxidation of the oil itself.
  3. Owner neglect to prolong the intervals for changing oil and filters recommended by the manufacturer.