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Probably 40% of the 7.3's are sold for commercial use. Take oilfield, railroad, or mining: these guys drive to jobsite, then often wait many hours until their specific work is needed. Meanwhile they idle the company truck for endless hours with AC or heat on as they play with their phone.
If excessive idling was killing these engines I think fleet owners would have raised hell with Ford by now.
The real test for these 7.3 engines is in EMS trucks. Read a report from a guy over at RV.net last year and he stated the 7.3 were still not as reliable as the V10 engines.
I did some reading through the service manual this morning and played around with ForScan for some live data logging. It was interesting. According to the manual, if you unplug the solenoid and start the engine, you should see a minimum 40psi rise in oil pressure and yes it will set PO6DD. That to me says you can defeat the variable displacement functionality.
Cold startup, the oil pressure was right at 95 and stayed there for about 20 seconds then it went down to 28ish and held there independent of RPM. Note the oil pressure is abs.
That video shows how the oil pump varies its output. The pump cannot do that on its own.
What it does not go into is the hydraulic control circuit which varies the displacement. It does however confirm that it defaults to maximum displacement when no control is applied.
That video shows how the oil pump varies its output. The pump cannot do that on its own.
What it does not go into is the hydraulic control circuit which varies the displacement. It does however confirm that it defaults to maximum displacement when no control is applied.
I thought what changed the displacement of the pump was the rpm of the engine. Putting more or less pressure on the spring he mentions in the video which changes the displacement of the pump.
I did some reading through the service manual this morning and played around with ForScan for some live data logging. It was interesting. According to the manual, if you unplug the solenoid and start the engine, you should see a minimum 40psi rise in oil pressure and yes it will set PO6DD. That to me says you can defeat the variable displacement functionality.
Cold startup, the oil pressure was right at 95 and stayed there for about 20 seconds then it went down to 28ish and held there independent of RPM. Note the oil pressure is abs.
So the truck does have a real oil pressure sending unit somewhere. I thought it only had a pass/fail sender and that's why we cannot see real oil pressure on the dash.
I did some reading through the service manual this morning and played around with ForScan for some live data logging. It was interesting. According to the manual, if you unplug the solenoid and start the engine, you should see a minimum 40psi rise in oil pressure and yes it will set PO6DD. That to me says you can defeat the variable displacement functionality.
Cold startup, the oil pressure was right at 95 and stayed there for about 20 seconds then it went down to 28ish and held there independent of RPM. Note the oil pressure is abs.
Very interesting, wasn’t aware Forscan had that capability. Would be interesting to see the stock oil pressure once the engine is fully warmed up (assuming that it wasn’t) with oil temp around 190 degrees. If it is still in the upper 20 psi range wouldn’t that be sufficient to lubricate the engine? Only asking because I have no clue and have seen people saying on the forums that it is probably around 8 or 10 psi at idle.
So the truck does have a real oil pressure sending unit somewhere. I thought it only had a pass/fail sender and that's why we cannot see real oil pressure on the dash.
Originally Posted by saratoga2011
I did some reading through the service manual this morning and played around with ForScan for some live data logging. It was interesting. According to the manual, if you unplug the solenoid and start the engine, you should see a minimum 40psi rise in oil pressure and yes it will set PO6DD. That to me says you can defeat the variable displacement functionality.
Cold startup, the oil pressure was right at 95 and stayed there for about 20 seconds then it went down to 28ish and held there independent of RPM. Note the oil pressure is abs.
I thought what changed the displacement of the pump was the rpm of the engine. Putting more or less pressure on the spring he mentions in the video which changes the displacement of the pump.
As he stated in the video, the spring pressure is controlled by a solenoid.
Also as he stated in the video, and as saratoga2011 has confirmed, when the solenoid is disabled, the pump defaults to maximum volume and pressure.
He never says the word “SOLENOID” in the video. He just says “THE CONTROL”, so he’s referring to a solenoid when he says “THE CONTROL”?
Yes, the solenoid regulates oil flow into the control circuit, which works in opposition to the spring. Which is pretty much what you said, other than the flow in the control circuit is not mechanically controlled by rpm.
Still makes absolutely no sense that only Super Duty trucks built from (1/4/23 - 4/11/24) at KTP, and (3/8/24 - 4/11/24) trucks built in Ohio, and Econoline built from (5/31/19 - 4/11/24) qualify for this update. The one common denominator is it looks like the fix was in on (4/11/24) and this issue is serious enough that Ford put a delivery stop on these trucks until this update get's implemented.
Ran the same data log again right after I ran some errands with a bit of 70mph driving so everything was hot. Coolant was like 195, oil and trans were both 200 if memory serves. Looks like oil pressure was steady around 20-21 psi. Didn't matter whether it was in park or in gear idling. Pressure did come up to around 50 when I raised the RPM up to about 2,000 in drive.
@saratoga2011
How were you able get the actual oil pressure values?
I found a DTC for variable oil pressure on some other more mainstream Ford vehicle, looked that up in service data for the 2023 F250 and found the procedure to test the oil pressure control solenoid which gave the PID to monitor.
Setup the same PID in Forscan and monitored live data.
Yes, the solenoid regulates oil flow into the control circuit, which works in opposition to the spring. Which is pretty much what you said, other than the flow in the control circuit is not mechanically controlled by rpm.
So if you remove this connector you essentially disable the variable oil pump portion of the pump?
