Essential oil filter fault-finding guide

Leading parts specialist MAHLE publishes oil filter troubleshooting advice

Essential oil filter fault-finding guide
Opened oil pump with integrated regulating valve.

International development partner and supplier to the automotive industry, MAHLE has released an oil filter fault-finding guide for technicians.

Oil pressure regulating valve clogged

In vehicles with spin-on (OC) oil filters, leakage from the filter or oil loss from the filter’s screw-on flange may occur due to a clogged control valve in the oil pump.

This is visually confirmed when the seal has become dislodged or the filter housing has expanded, or even burst in some cases.

This can typically be attributed to deposits and carbonised residue in the engine oil that are swept through the oil pump, where they cause sporadic clogging of the control valve.

Close-up view of the clogged control valve.

Since the oil pressure is no longer adequately regulated or may even cease to be regulated altogether, extreme pressure peaks of over 30 bar may occur as a result.

The oil filter is unable to compensate for this tremendous rise in pressure and deforms.

The seal may also become dislodged or the end cap may bulge significantly, giving rise to insufficient contact pressure between the seal and the filter.

Oil filters, side-by-side comparison: left is normal and the right filter is deformed.

As a result, oil is lost directly from the screw-on flange or the filter bursts—in which case the entire end cap detaches from the housing.

In the damage scenario described above, it is not enough to replace the filter.

It is essential to make absolutely sure that the entire oil circuit is inspected and flushed to remove all deposits.

The oil pump may also need replacing (with integrated regulating valve).

Damaged oil filter paper

If during an oil change, the filter paper in the old oil filter insert is found to be deformed or damaged, there are several possible causes.

The first and most common reason is noncompliance with proper maintenance and replacement intervals. The oil filter is worked too hard, reaches its maximum absorption limit, and collapses.

The second possibility is continued operation at high engine temperatures, which makes the filter paper age faster and the impregnation layer become brittle.

Collapsed oil filter inserts.

The third possible cause relates to carbon build-up in the engine.

As a result, the oil pressure regulating valve can stick, therefore damaging the filter.

Other circumstances can also result in damage to the filter paper, such as increased fuel input and a high biofuel content in the engine oil.

An increase in short journeys and advanced engine wear can also lead to shorter replacement intervals.

Besides complying with the manufacturer’s specifications, oil and filter changes should always be to suit the individual driving profile.

The use of high-quality engine oil can also significantly reduce the load on the oil filter.

For further information about MAHLE, click ‘more details’ below.

Have your say!

0 0

Lost Password

Please enter your username or email address. You will receive a link to create a new password via email.