I have noticed that the oil pressure guage on my Cat D3G 2005 is sometimes erratic. Or maybe the oil pressure is errratic. When I start my machine it normally shows about 50 psi. After I am operating for a while, it settles down in the 40 to 45 psi range. It may even drop off just below the 40 psi line if it is idling at the lowest govenor position. Recently it has been reading 60 psi at start up. It settles in at about 50 psi after operating a while and will read about 45 at idle. A few times while I was on the machine at start-up, I watched the pressure guage and I saw the needle swing all the way over to 80 psi and then swing back to 60 psi. It did this little trick about 3 times over a 3 minute period. It finally settled down and ran all day at about 45 to 50 psi. The question is two-fold, one, why the increase of about 5 psi that I have seen over the past couple of months (or over the last 100 hours of operation) and , second, why the spike to 80 and then return to normal during start-up. I have never seen it above 55 psi during operation. That phenominum only occurs at start-up. The machine has 2100 hours on it. I have put the last 500 hours on it. The engine ( 6 cyl 3046T) and all parts are original and un-modified. The machine operates very well. Starts right up, has great power and response. So I am not really experiencing any problems. Just want to know if a problem is coming!
The first thing to do is attach another pressure gauge that you can monitor and compare to the oem gauge. If they agree you probably have a pressure relief that is sticking or a bad gauge,sender or a wire grounding out.
I have the same problem with my d5 looking through the service manual it states This condition will occur when an oil pump bypass valve sticks in the closed position and the full pump volume is directed to the engine bearings.
Shawneecat, Is this something that needs to be fixed? It only occurs infrequently and during start-up.
I have been running my machine like that only I know to fix is to replace oil pump
Thanks
You might try adding some Marvel Mystery Oil to the engine oil.Sometimes this will free up sticking Valves.I used it to free up sticking lifters in a gas engine.Next time you change oil add some.Might help.
What do you think about automatic transmission fluid 2stick? It would also dissolve crud built around the bypass value.
Be worth a try.I just know about the Marvel oil on sticking hydr.lifters.Now I have added Automatic Tranny fluid to diesel fuel in a Cummins because of gauled injectors.Worked too.Till we had time to replace them.
You will want to get this checked out soon. We recently had a D6R blow off an oil filter, and the turbo went out around the same time. It turned out that the oil pump relief valve was sticking. When the pump valve was stuck the oil was not being filtered, it was going straight through the filter bypass. We checked the rods and mains and saw some issues there as well. We are leaning to the extreme oil pressure causing the damage because the motor had been built by a Cat dealer less than 400 hours prior to this. Good luck.