On a Ford Powerstroke 7.3 Diesel High Pressure Oil Pump, what does the Oil Pressure Sensor on the oil reservoir do? It does not appear to be attached to any light or gauge that would show a drop in oil pressure. How does it work or what does it do? Thanks, Donna

Is that a fluid level sensor?
Two wires, Light green w/ red and Gray w/ red?
That would be for fluid level in the reservoir.

I believe that I was told there is 1 wire but I am not sure.

I understand what it's for and what it 'should' do, but am not convinced it is doing anything.

As I stated in my original question, it's not attached to any light or gauge of any kind, therefore how can it tell you what the fluid level is?

Unplug the connector with the engine running...

You say it does not look like it goes to anything, can you actually see the end of bare wires? Make sure you post the model yr. Because in model changes yours could be slightly diffeent than another. There are all kinds of sensors that give info to the computer, but do not "show" anything.

Does it start and run?

We have a 1997 Dually and I learned a lot from here. (our first diesel)
A good place to start would be Diesel - Ford Truck Enthusiasts Forums



They have forums for individual yr/body style Diesel's or any ford truck.

A lot of them post pics, schematics.

ALZ1

My original question came from our mechanic. He wanted to know if there was a light or some way the sensor will tell you if the reservoir or the pressure on the high pressure oil pump is low. Just one of those little things that bugged him and he asked me if I would get on-line and see if I could find an answer for him.

I don't believe you can see any bare wires. I honestly don't know without asking him. Perhaps it does just talk to the computer?

At this time it is not running. It just would not start one day and we could never get it started again.

We have replaced the computer, drive module, glow plugs, wire harness, cam sensor and several other things. The high pressure oil pump is about the last thing to try and we are in the process of getting that done now.

It is a 1995 F250 and it is our first diesel also. We have had it for several years and love it. Can't wait to get her running again.

Thanks for the information and the other website.

I will pass this along to the mechanic and he can try it - once he gets the truck to run of course. Maybe this will answer his question. Thanks.

Donna, you are asking for our help, but you gave incomplete information: what year is the truck?

Upon further checking of online data, the sensor on the high pressure oil pump is for oil temperature, not oil pressure.

The Engine Oil Temperature sensor is a thermistor mounted to the oil reservoir whose resistance decreases as engine oil temperature increases. The Engine Oil Temperature signal is used by the PCM to calculate fuel quantity, injection timing, glow plug operation and exhaust back-pressure.

At low ambient air temperatures, and oil temperature below 50°C (122°F) , low idle is increased to a maximum of 1300 rpm to increase engine warm-up. Fuel quantity and timing is controlled throughout the total operating range to provide adequate torque and power.

An Engine Oil Temperature signal detected out of range, high or low, by the PCM will cause the PCM to assume an engine oil temperature of 20°C (68°F) for starting purposes and 100°C (212°F) for operating purposes. The Malfunction Indicator Lamp in the instrument cluster will be illuminated as long as the fault condition exists.

OUCH! There are things on a diesel that work in a different way gas engine if I am not mistaken.
If he is asking you what a sensor does...


Do you see the RPM needle move while turning it over?

Water in fuel bowl, clogged fuel filter, fuel screen on the bottom of the bowl.
We change our fuel filter every other oil change.




How was it acting before it had to go to a mechanic? Dying, chuging, lack of get up and go.

ALZ1

Comments on this post
CaptainRich disagrees: I don't have the truck in front of me so I rely on the info you give. Obviously, you don't know what you're talking about. Get more info before asking for any more.


Well Captain Rich, I humbly apologize for not knowing what I am talking about.
I thought that was why this forum was here - to ask questions. My mistake.

I also apologize that I did not give all the right information. I'm sure that everyone else knows better.

This is the first time that I have used such a forum. I am not a mechanic and being a woman have no desire to be one. Obviously I have failed miserably at my first attempt to use such an avenue to get an answer for my mechanic.

Please forgive me. Donna

I'm sorry but I'm not able to answer most of your questions.

All I know is one day my husband went to start it and it wouldn't start. It has not started since and that was months ago. It has been at our mechanics house for several months while we save some more money to put yet another new part in it to see if that will be the right fix. My husband does the general maintenance, oil changes, fuel filter, etc. but this was not something he could figure out. Hopefully after replacing the high pressure oil pump it will run, if not I don't know what else they will do.

I thank you for trying to help me and for trying to answer my original question, which at this point I honestly wish I had never asked. Thank you, Donna

Its OK, I deal with it every day talking men too not just women. (day job)

PSD parts are not cheap as you know and to go on guessing is going to cost you dearly.
like what??

Then what does your husband know? Pick his brain, some times women have to do that with some men if he will let you. NOT all men... No offence to any of you men out there!!
If "they" want you to find out this stuff, make "them" give you more info.

Print or write stuff down to relay the message as clearly as possible.
I guess in the end it is a matter of how much money you want to burn, compaired to how much info you want to write down/print and relay.


How was it running before?
Smokes when starting or tuning over?

I don't like to assume, so...
Dumb? but did he check the fuses under the hood?
Clean battery connections, charge batteries over night?.
Check the battery ground?
It takes both batteries to be functioning Fully. Do it just in case. Fuses too.
After each thing you have replaced, you try to start it---each time the batteries do not get recharged by the alternator(because it does not start and run)---sitting over time you loose some battery power. Especially months.

Check the oil level in the high pressure oil pump itself?
Fuel bowl screen inside at bottom driver side of bowl?
Make sure fuel is in bowl?
Check HPOP to make sure it was full.

Your mechanic:
A friend that works on cars?
He do it for a living?
And either is OK, just so people know.
Did he scan it for code? (If I remember correctly one of those cost less than a HPOP.still not cheap.)
Send him to the post to read it or respond.


Oh the Crankshaft sensor is located just above and to the right if the harmonic balancer. It is held on by a 10mm bolt.
Is that the one he changed?


http://www.forddoctorsdts.com/articl...icle-06-08.php Link to pdf files on different yr PSD. Some files are 39mb

http://members.cox.net/calico5string/HPOP%20Manual.pdf direct link to HPOP technical info. And some things to test and look at on the HPOP.
Pictures too...
New Page 0


I hate to see a PSD just sitting there...
ALZ1

Oil Pressure Gauge not working on Intrucment panel of F-Series F350 7.3. I have replace the Oil sending Unit located under the Hood. I cannot find a Fuse for the Instrument Oil Gauge.

The sensor on top of the HPOP reservoir is the oil pressure switch that goes to the gauge. The gauge on the dash is not an actual gauge but is just on-off at 6psi.

As to the engine not starting, the most likely cause is the Cam Position Sensor. Ford has a recall on this part. It should show up if you pull codes if that is the fault.

For hsaylor, I am fighting a similar problem on my PowerStroke. One comfort you can take is that if you truly don't have oil pressure the engine wouldn't run at all. Where the pressure is measured is at the HPOP, High Pressure Oil Pump, reservoir. If there is no oil pressure there the HPOP wouldn't get oil and the injectors wouldn't fire. Chances are it is a connection somewhere. I haven't looked at the fuse or wiring diagram lately but I would expect that there wouldn't be a single fuse for the oil gauge alone. It would most likely be a fuse for more of the stuff on the dash if not the entire instrument cluster.