DBLXX Posted June 6, 2014 Share Posted June 6, 2014 Would there be any correlation between oil pressure in an engine and the life of the oil? Will the oil pressure number on a meter go up or down as the oil ages and gets dirty, thinner and begins to break down? Thanks Quote Link to comment Share on other sites More sharing options...
rockmeupto125 Posted June 6, 2014 Share Posted June 6, 2014 The relative viscosity of the oil degrades with use, and that may show as a decrease in oil pressure. It would take an amazing amount of contaminant to increase the viscosity/oil pressure. Any decrease in pressure should, in my opinion, be less than 10% from baseline or its an indicator of something wrong. Bear in mind that I'm speaking of a warmed engine, not the variances that occur during cold startup. Ambient temperatures may also play a role as the warm summer months are upon us......keep an eye on your temp gauge as well. Higher temps will equal lower pressures. Quote Link to comment Share on other sites More sharing options...
DBLXX Posted June 6, 2014 Author Share Posted June 6, 2014 (edited) OK...so if I get a digital oil temp reading and a digital oil pressure reading I should be looking for a higher number in temperature and/or a lower pressure number from what it reads after a fresh change? Nothing wrong with the bike....just a interesting experiment to keep track of and plot. Thanks Joe. Edited June 6, 2014 by Dave_K Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 6, 2014 Share Posted June 6, 2014 For the most part, I think the whole analysis is purely academic. Your oil fill is way more than minimum the engine needs...to compensate for oil loss via a number of likely means. I don't see how oil pressure is representative of any volumetric indicator of oil amount or condition. Your "low pressure" light comes on when you are below the minimum you are supposed to have or have otherwise suffered a catastrophic loss in the system. I'm sure the PSI rating on a healthy oil system has a significant range reflecting many situations but it's only a concern if it drops below X once the engine has been running for several seconds. Quote Link to comment Share on other sites More sharing options...
jon haney Posted June 6, 2014 Share Posted June 6, 2014 Dave didn't mention anything about volume, Mike (AKA Mister A.D.D.). Quote Link to comment Share on other sites More sharing options...
Zero Knievel Posted June 6, 2014 Share Posted June 6, 2014 Well, my point is that if you have a sufficient quantity of oil, your pressure will vary between a normal high and low point...I don't see how you'd know much about the condition of the oil short of it dropping well below that low point or shooting well over the high point. The variations from wear or temperature effect on viscosity probably are very difficult to distinguish from one another. Quote Link to comment Share on other sites More sharing options...
tomek Posted June 6, 2014 Share Posted June 6, 2014 The variations from wear or temperature effect on viscosity probably are very difficult to distinguish from one another. Oh boy. Quote Link to comment Share on other sites More sharing options...
RXX Posted June 6, 2014 Share Posted June 6, 2014 Get a digital ZDDP meter and use that to get a fractionate representation of the inverse sine of the viscocity/lubricity coefficient. That'll tell you all you need to know, and there is a bluetooth functionality that will send a text when tolerances fall outside predetetermined +/-pi values. This only works at near sea level (standard temp and barometric pressure of course) which of course, living in New Joisy is not a probelm for you. I think there is an app that warns you of impending systemic engine failure by a degradation of Neil Piert's drum solos into dilettantes thrashing one of the shrines of percussion. 3 Quote Link to comment Share on other sites More sharing options...
CALCXX Posted June 7, 2014 Share Posted June 7, 2014 Phillip, you are absolutely brilliant. LMFAO. Damn near choked on the pop top. Still rollin on the floor. Quote Link to comment Share on other sites More sharing options...
TOXXIC Posted June 7, 2014 Share Posted June 7, 2014 As has been mentioned, the viscosity of the oil will impact oil pressure. I have an older Jeep Wranger with almost 200K miles and I see noticable oil pressure increase in the gage with thicker oil. To answer your first question, yes, oil will break down over time and you will possibly lose oil pressure. Oil pressure will go down with aged, or worn oil However, that is relative as everything you own and drive is brand new, not like the flogged 200K mile Jeep I referenced above. So you might not see a discernible drop in oild pressure over 6-8K miles. Quote Link to comment Share on other sites More sharing options...
tomek Posted June 8, 2014 Share Posted June 8, 2014 Some people here are trying desperately reinvent the wheel. Just RTFM and follow recommended drain intervals. Quote Link to comment Share on other sites More sharing options...
TuffguyF4i Posted June 8, 2014 Share Posted June 8, 2014 (edited) You guys know that oil viscosity is supposed to change, as the engine warms? 10W40 will vary somewhere between 10 and 40. And as it gets chewed up by motorcycle gears, 5 and maybe as low as 20. Dave. I think your oil pressure will stay very close to the same PSI even as it degrades. For all practical purposes, it is a closed loop system and the pump sustains the needed pressure unless something is very wrong. Zero is right,, the PSI for healthy engine wear is likely a wide range. Edited June 8, 2014 by TuffguyF4i Quote Link to comment Share on other sites More sharing options...
tomek Posted June 8, 2014 Share Posted June 8, 2014 You guys know that oil viscosity is supposed to change, as the engine warms? 10W40 will vary somewhere between 10 and 40. And as it gets chewed up by motorcycle gears, 5 and maybe as low as 20. Dave. I think your oil pressure will stay very close to the same PSI even as it degrades. For all practical purposes, it is a closed loop system and the pump sustains the needed pressure unless something is very wrong. Your two paragraphs contradict each other. Yes, there is relief valve but it only regulates maximum pressure. I don`t think you understand how lubricating system works, it is kind of open, oil from various parts of the engine drips down to the oil an where it starts its journey again. In the nutcase pressure at given point of lubrication system in the engine depends on rpm and viscosity. So different oil can give varied pressure readings all other things being equal. I have a high quality aftermarket oil pressure gauge in my rx7. I had a fairy large and thick (3.5 ich) intercooler blocking somewhat the airflow to the oil cooler. I have since re- engineered my radiator/intercooler/ac/oil cooler arrangement so it now get unobstructed flow of air. The oil pressure for given driving conditions went up by 20-25 % . Why ? Because the oil temps went down and consequently viscosity went up. Quote Link to comment Share on other sites More sharing options...
RXX Posted June 9, 2014 Share Posted June 9, 2014 (edited) You guys know that oil viscosity is supposed to change, as the engine warms? 10W40 will vary somewhere between 10 and 40. And as it gets chewed up by motorcycle gears, 5 and maybe as low as 20. Dave. I think your oil pressure will stay very close to the same PSI even as it degrades. For all practical purposes, it is a closed loop system and the pump sustains the needed pressure unless something is very wrong. Your two paragraphs contradict each other. Yes, there is relief valve but it only regulates maximum pressure. I don`t think you understand how lubricating system works, it is kind of open, oil from various parts of the engine drips down to the oil an where it starts its journey again.In the nutcase pressure at given point of lubrication system in the engine depends on rpm and viscosity. So different oil can give varied pressure readings all other things being equal. I have a high quality aftermarket oil pressure gauge in my rx7. I had a fairy large and thick (3.5 ich) intercooler blocking somewhat the airflow to the oil cooler. I have since re- engineered my radiator/intercooler/ac/oil cooler arrangement so it now get unobstructed flow of air. The oil pressure for given driving conditions went up by 20-25 % . Why ? Because the oil temps went down and consequently viscosity went up. Yes, mine is fairly large and thick also. Unlike yours, though, mine is not a blower. But it does get blown. Edited June 9, 2014 by RXX Quote Link to comment Share on other sites More sharing options...
CBRXX Posted June 9, 2014 Share Posted June 9, 2014 drive it and make sure it doesnt drop to zero. Quote Link to comment Share on other sites More sharing options...
TuffguyF4i Posted June 16, 2014 Share Posted June 16, 2014 You guys know that oil viscosity is supposed to change, as the engine warms? 10W40 will vary somewhere between 10 and 40. And as it gets chewed up by motorcycle gears, 5 and maybe as low as 20. Dave. I think your oil pressure will stay very close to the same PSI even as it degrades. For all practical purposes, it is a closed loop system and the pump sustains the needed pressure unless something is very wrong. Your two paragraphs contradict each other. Yes, there is relief valve but it only regulates maximum pressure. I don`t think you understand how lubricating system works, it is kind of open, oil from various parts of the engine drips down to the oil an where it starts its journey again.In the nutcase pressure at given point of lubrication system in the engine depends on rpm and viscosity. So different oil can give varied pressure readings all other things being equal. I have a high quality aftermarket oil pressure gauge in my rx7. I had a fairy large and thick (3.5 ich) intercooler blocking somewhat the airflow to the oil cooler. I have since re- engineered my radiator/intercooler/ac/oil cooler arrangement so it now get unobstructed flow of air. The oil pressure for given driving conditions went up by 20-25 % . Why ? Because the oil temps went down and consequently viscosity went up. Where are you measuring that pressure? At the pump? I'm sure as oil cools and viscosity increases the pump is doing more work and it has more resistance against the pump. You will also be picking up resistance through the entire system. Thanks for the info. Always happy to learn more. Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted June 26, 2014 Share Posted June 26, 2014 Depending on the contaminants accumulating in the oil while it's breaking down through use the pressure may rise or fall. I doubt the pressure change would be measurable unless you ignored changing the oil for a very long time. Quote Link to comment Share on other sites More sharing options...
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