mygusto Report post Posted October 4, 2010 2003 Cummins 350 When I first start engine, oil pressure goes to 100 lbs. Lowers as engine warms up. Is this a serious problem? Share this post Link to post Share on other sites
wolfe10 Report post Posted October 4, 2010 What is ambient temperature? What viscosity oil are you using? What is reading after warm at idle/cruise RPM? Brett Share this post Link to post Share on other sites
mygusto Report post Posted October 4, 2010 Ambient is approx 70-75 degrees Viscosity is 15-40W Oil pressure is around 30/35 lbs after warming up. The oil has approx 400 miles since change. Thanks Brett Share this post Link to post Share on other sites
wolfe10 Report post Posted October 4, 2010 I made a quick call to the Cummins Hotline (800 343-7357, 0) . The short answer is that this is a non-problem. Brett Share this post Link to post Share on other sites
mygusto Report post Posted October 5, 2010 I made a quick call to the Cummins Hotline (800 343-7357, 0) .The short answer is that this is a non-problem. Brett Thank you my friend. How easy it was for you to make somebody's day better. Share this post Link to post Share on other sites
clintonmotor Report post Posted October 10, 2010 Our Monaco Windsor 1999 with 80,000 miles with a 330hp Cummins runs the following pressures. Oil Pressure on the 8.3 330hp or 350hp. Starting the engine it will run 120lbs of oil pressure. When running down the highway it will run about 80-90lbs. At Idle 35lbs. These are normal pressures for these Electronic engines 1999 and newer. So, don't be alarmed with high oil pressure in these engines. My Kenworth T300 had 327,000 miles on it and it did the same thing, but it is how you maintain your engine. My recommendation is use the best oil and best oil filters that money can buy and change it frequently. Phil Barr - Michigan Share this post Link to post Share on other sites
deenad Report post Posted March 3, 2011 My recommendation is use the best oil and best oil filters that money can buy and change it frequently. Phil Barr - Michigan Oil and filters are CHEAP compared to a rebuild!! And cheaper yet if you do the work yourself like I do. Share this post Link to post Share on other sites
Spike45 Report post Posted June 21, 2011 2003 Cummins 350 When I first start engine, oil pressure goes to 100 lbs. Lowers as engine warms up. Is this a serious problem? ISC 350? The specified minimum idling warm oil pressure is 15 PSI. Per the base engine data sheet for this engine, maximum cold start up oil pressure (spike pressure, no pun intended) is 150 PSI. Normal warm engine oil pressure is 45 - 50 PSI. This is about standard for all Cummins engines in the midrange class; B5.9L, 6B5.9, ISB, C8.3, ISC, ISL9. Share this post Link to post Share on other sites
MikeCanter Report post Posted June 21, 2011 Yes, Spike if we can control your spiking we will be doing good Share this post Link to post Share on other sites
