I was seeing so low oil pressure with my digital autometer gauge recently with the warmer weather. I saw as low at 4psi (from the furthest main by transmission) when coming off the throttle to a stop oil temps around 205F. Just idling not letting off the throttle itll see 7-8psi hot at 205f. The idiot light doesnt come on or anything, but i have noticed when its hot, the truck will start surging when i first start it for a second or two and the factory oil pressure gauges didnt kick on yet. It clears up when it does.

Anyway i installed a new melling pump tonight, took me about 4hr. I didnt remove the fan or shroud (first fan i couldnt get off with an air hammer) so i left it in place and just loosened the shroud and moved it around. I held the flexplate with a large pair of vice grips wedged against the bell hosuing. No issues loosening or torquing to 215ft lb that way. The teeth on the old pump look pretty rounded, or is that how the are supposed to be? Engine has 303k on it. Orgintal oil pump as far as i can tell, had gray rtv on the crank keyway, i put red back on and on bolt.

With the radiator in place i didnt have room for a long (6-8 inches) hamonic balancer puller, but a shortened stem from a tie rod puller (4") worked fine. 4 inch 3/8-16 botls were too long, i used 2 inch ones. I ran a tap through the 3 holes before threading them in too, they were pretty corroded. I purchased a 70mm 16mm bolt to pull the balancer back on carefully, then when that got tight i put in the old bolt. It went in about 4 turns by hand and i didnt have any issue pulling it on that way.

Anyway does this pump look worn? My injector have 303k on them too they looked orginal as they had the old style hardnesses too, and the oil stays amb colored until about 4k in this truck. It seems to be sealed very well so i cant see bearings being trashed. I didnt get a chance to take it for a ride i just let it idle. Idling around 36psi with 140f oil (engine was still warm from when i changed it) I will report back tomorrow to see if it changed any. It did fire right up immediately, like 2 revolutions, i was pretty impressed how quick it primed.

 

Curious if the LPO sensor was reading correctly. Rarely due LPOPs go out on these ,and when they do she simply quits as the reservoir will not remain full. Typically its a quit failure and not a progressive failure. What does it read now with the new one? Pump looks fine to me, However Im not an expert on the tolerance allowance on the tooth spacing.

 

I can still see the oil pressure drop to 5psi or so letting off the throttle coming to a stop. Hot idle is up to 10ps in drive, 12psi in park, i cruise at 60mph/2000rpm is up to 38psi. It was around 35-36 before. I have my sender in the rearmost main on driver side.

maybe I need to start looking at some new injectors. The hot restart issue was still here. Maybe 2-4 seconds of cranking before it fully catches and fires up.

In the past 10k/8 months, new batteries, cables, motor craft ipr, glow plugs, motor craft Icp, international CPs, rebuilt idm, efuel kit, rob valve who like, rebuild oil Cooler with new bundle removed inspected and cleaned regular staked back in.

Im not so worried about the oil pressure as I am the extended cranking at times. Sometime I fires right up sometimes it's 4 seconds where it sounds like it's firing by just not catching then it fires right up. It hasn't surged today yet. I've tried the stock towing and daily tunes for it.

Im gonna hook auto Enginuity up to it when I get home and look at ipr again. I know before I could see 3300psi at only 35% when I had a no start because of idm. Maybe an injector oring went or something. Mileage has been consistent no additional oil consumption. I drive it 100-200 miles a day

 

I can't believe the oil pressure is THAT low. Are you confident in the gauge and where it is located?

 

I had it on my old truck. It replaced a glow shift oil pressure gauge that i thouugh may be innaccurate. It was at lower pressure on an IDI turbo i had (it was reading 10 and would then drop to almost 0psi). This gauge is far more accurate and gave me a true reading of 3-11psi on that engine at hot idle. Most gauges aren't rated for low pressure. What gauge are you using? It's an Automter rated to read as low at 5psi. I may pull the sender and wire it to a manifold with a mechanical gauge to double check but im pretty cofident its accurate. What are you reading pressure with?

2-1/16" OIL PRESSURE, 5-100 PSI, COBALT DIGITAL

 

I also have it tapped in on the driver side rear of the engine almost to the bellhuosing. If that's the last part of the mains feeding the turbo i am not surpised. On my IDI turbo i had it tied into my turbo oil feed line which was the same feed location based on the block. And despite what everyone argued with me that a worn turbo bearing wouldnt affect oil pressure, i replaceced it with an BW SX257 turbo and magically gainedlike 6psi at idle. If it's the last run of oil line and going through an extremely small turbo bearing the size of that orifice will directly affect oil pressure. I could also tee the gauge into the idiot light/gauge port but im not concerned about oil pressure there, i wasnt to know what pressure my turbo is seeing. My turbo is most definitely the orginal turbo with 303k on it and i would not be surprised that bearing is pretty worn.