A Plugged Motor Oil Filter Can Spell Disaster
Wednesday, September 8th, 2010Here’s a scary picture to put yourself in…you’re driving down the highway like any other day and all of a sudden the oil quits flowing inside your motor…can you imagine that? There’s no way your oil could pass through its filter. We put a lot of faith in a tiny light bulb to warn us of a potentially serious oil problem. Disaster happens fast at 2100 rpm and highway speeds!
When oil stops flowing to the engine you lose critical lubrication and cooling. Catastrophic seizure is imminent.
Oil filters are designed to handle so much contamination loading before they need to be replaced. ‘Designed’ is a word I use with some hesitation since I think there are those less than honest companies out there who pleat some paper media, stuff it in a can and say they have a decent oil filter. My engine deserves more than a kindergartener’s adaptation of a fan made out of paper for an oil filter.
Luckily, oil filters have a bypass valve that’s spring loaded so if the paper or synthetic media gets blocked for some reason, there may be some hope. This bypass valve opens at a specific pressure differential that varies between vehicles. Through overuse of the media in the filter, blockage can occur and when it does, oil will use the bypass valve to flow through. This is ok for a quick fix to get you home or to the shop, but by no means should you run your vehicle like this because your oil isn’t getting filtered anymore.
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!).Sometimes an indicator of this problem will present itself using that little light bulb, you know…the one we have so much faith in, that says your oil pressure downstream of the filter is low (and hope that your oil filter bypass valve is working properly!). It’s pretty safe to say that the decrease in pressure may not be enough to turn your oil light indicator on.
The bypass is also prone to open on startup when your motor oil is cool and thick. The pressure drop through the filter media is too high to let all of the thick oil pass through, so some oil has no choice but to travel through the bypass filter. Again this causes unfiltered oil to pass up into the engine. Don’t worry too much though it has been like this for years and engines have done pretty well.
The real damage is done when an oil filter is left unchanged for long periods of time, and ends up blocked for long periods of time. Preventable and unnecessary wear and tear will occur as unfiltered oil surges through your engine.
