What kind of internal disaster would result in your engine if oil stopped flowing while driving at highway speeds? If your engine was not getting oil flow past the oil filter . We just hope the little idiot light turns on let us know there is a problem with our oil system . Disaster happens fast at 2100 rpm and highway speeds !
If your oil stops flowing there is a loss of critical lubrication and critical cooling of your engine . An engine disaster is imminent .
Motor oil filters are designed to capture a certain amount of contamination before they need to be swapped . I say designed loosely because I believe some companies know how to assemble filters but don’t really know how to design and test them . I personally want more for my engine .
Regardless, if the synthetic or paper filter does become obstructed oil filters have a bypass valve which is spring loaded . This bypass valve opens at a specific pressure differential that varies between vehicles . If the media does get overused and blocked then oil will flow through the bypass valve. When the bypass valve is open dirty unfiltered oil is pumping up into your operating engine .
Sometimes this will show up as an oil light indication that there is low oil pressure downstream of the filter (hopefully your oil filter bypass valve is not stuck!). I can guess that sometimes the pressure decrease is not enough to cause an oil light indication.
Bypass valves tend to be open when you first start your engine when your motor oil is cool and thick. The pressure drop through the filter media is too high to pass all the thick oil and some has to go through the bypass filter. Again this causes unfiltered oil to pass up into the engine. Don’t worry too much though lubrication system and filter design has been like this for years and engines have done pretty well.
The problems occur when oil filters are not changed for long periods of time and become blocked for extended periods of time. Unfiltered motor oil can then continuously circulate through your engine and cause extensive wear.
