I'd say it depends on useage.. I have a 6bt with 350,000 miles.. and it idles at about 15 fully warmed.. 65-70 cold... buyt notw powered up.. factory oil pump is fine unless you are doing high rpm /high power I don't see the point... but if you are going to replace the oil pump... Id suggest changing the cam bearing at the same time.. you'll be there anyways..Any thoughts about going with a high volume pump? Diesel tuff has 5346430 for sale listed as a high flow for the 4bt. I am running a HX30W which may be taking some extra oil
so if that doesn't work , check for a spun bearing.. like the cam bearing..So I finally got this thing put back together, I pulled the pan and pickup to clean and inspect, and also replaced the oil pump. I took it on a drive and got it warmed up, I was thrilled that after it was up to temp, my idle psi was around 40! Then as I kept driving, it wouldn’t come below 80 at idle, and acceleration would put it well above 120. Idled home and shut it off, restarted and it was perfect again, 30-40 at idle. Drive it around the block, pulled in the driveway and it was zero at idle unless I fed it some fuel. So I guess I’m looking at the oil regulator/and oil bypass seems like the regulator may be sticking. I do see some wear marks on the plunger, is it possible to polish these? Or just replace?
I’m using a glow shift multi gauge, but the factory gauge fluctuates as well.Sure does sound like the regulator is malfunctioning. Also, the bypass should kick in around 65 PSI so this is really odd. Don't believe you've ever mentioned what type engine block, oil filter housing you have and which type gasket. You could have a miss match of parts there causing problems.
Great info, I’ll probably pick one up and pull it apart and replace it, and the bypass if it keeps acting up. Do you know if the regulator plunger is specific? Or does the 3918428 cover all?You have the standard 4bt engine block and it is likely a CPL 0767. The thing that identifies that CPL is that tilted exhaust manifold was only found on that one as far as I know. That tilted manifold was discontinued because they found it caused premature wear on the turbo bearings. The gasket for that filter head would be Cummins part 3929792 shown below. You can find those as cheap as around $7 to $22. If you need an engine serial number to look up parts you can try 44205343 or 44216332. They are both CPL 0767 but have different injection pump models. Neither of those ESN's show the exhaust manifold since it is no longer used.
a spinning bearing will some times block the Oil hole to the bearing.. causing an increas in pressure.. and when it spins back to the original position.. so the oil flow hole is open... you'll lose most if not all oil pressure.. because the bearing is too loose..