IDIT oil pressure delay

[Tim McKay]

Truck: 1993 IDIT 7.3. Ford Reman engine has about 15k miles. Good hot oil pressure of 65-70psi.
I have searched the forums, but have not found an answer to this particular question. I am aware a delay in building pressure is “normal”, but the delay I have seems more excessive. I recently installed a electric sending unit at the stock location at the turbo. If cold, the truck can warm for 5 minutes or more before seeing pressure build. If you drive after starting, it can take a 1/4 mile or so before it builds. If after driving, you stop to fill both tanks, or go into the hardware store, the pressure does not seem to leak down, and at startup its near or at its max.
Does the sending unit being at the turbo further delay the pressure build? It doesnt seem logical for the short tube run from the stock N/A sender location for it to take so much longer for pressure to build.
Thanks for all your help in advance

 

[IDIBRONCO]

Yes it will have a little longer delay with the sender in this position, but not 5 minutes worth. Maybe you should try another location to pull oil pressure from. If that doesn't help, try a different gauge/sender. If that oil pressure is accurate, you're doing engine damage with no oil pressure. I do doubt that it takes that long to build oil pressure. If it did, you'd have missing or a non running issue due to there being no oil pressure to the lifters.

 

[TNBrett]

Do you still have the factory oil pressure switch installed and feeding the dash? If not, what was it doing before you replaced it with the aftermarket gauge? I think your new gauge and sending unit may be at fault. 70psi hot seems pretty odd to me, and 5 minutes without oil pressure would kill an engine pretty quickly.

 

[Big Bart]

Sounds like a bad sensor, delayed reading, then a stuck reading.

 

[Tim McKay]

I used New Vintage gauges. I thought about the sending unit or guage being bad, but once it starts working, it works just fine. The original guage on the dash would just go to its predetermined spot, as I know its more of a switch than a guage. No funny behavior.
Well, the engine hasnt made any tell tale noises of no oil pressure yet, and I would think if there was something wrong, it would have happened by now. Another data point its the damn guage. You try to buy quality styff to do it once, and you get junk. I always doubt my logic on these things, but it sounds like its the sending unit or guage.
Oh, factory spec is 45-70psi, so that should be normal.
Thanks for your input.

 

[snicklas]

Also, make sure the hole you put the new sender in is clean. We had a member here kill a brand new turbo because there was schmoo in the hole in the block, blocking oil flow. If you took out a plug to install it, there could be 30 years of crap in the way between the sender and the oil.

Also, if you had issues with oil pressure building, you would HEAR it. I had a 2000 P71 that at idle, the oil pressure gauge would go nuts, it would go full swing and actually bang off each end of travel. It was an electrical issue, not an oil pressure issue, because there was no lifter tick and the engine didn’t seize up. I put an additional heavy ground wire from the battery negative post to one of the mounting bolts for the alternator that went straight into the block. Lots of strange little things dissapeared after that…. even the headlights were brighter……

 

[Tim McKay]

No lifter noises, I have been listening for that tell tale.
I will go thru the electrical….again, good idea on the ground, that can cause strange gremlins, once had a Corvette with ground issue nightmares. I plan on getting another sending unit based on above suggestion.
Thanks for the input guys.