03 5.4L 2V - new oil pump won't prime

[Eric M]

I just completed reassembling the motor after doing the head gaskets. I followed FordTechMakeuloco's procedure for priming the pump (crank motor with crankshaft position sensor unplugged until pressure guage shows pressure).

I did this several times with no change to the pressure guage. There should no issue with debris in the oil pick-up (timing guides weren't chewed up, etc.) and I definitely installed the o-ring between the pump and pick up tube.

I decided to remove the oil filter to see if oil was reaching it. It was full of oil BUT the oil was cloudy. I just added new oil!

So, I guess I have two issues that may be interrelated (??): cloudy oil and no prime.

Thanks in advance for any input you might be able to offer.

 

[Hamfisted]

It does take about 30 seconds of cranking for the oil to pick up and circulate before you get a oil pressure indication. How long are you cranking it ? I think you said you drained and installed new oil and filter, right ? Did the oil pump seem to seat correctly when you bolted it down ? Oil pressure sending unit still plugged in ?





.

 

[Eric M]

It does take about 30 seconds of cranking for the oil to pick up and circulate before you get a oil pressure indication. How long are you cranking it ? I think you said you drained and installed new oil and filter, right ? Did the oil pump seem to seat correctly when you bolted it down ? Oil pressure sending unit still plugged in ?





.

I cranked for 10-15 seconds, but I did so several times. I'll try the 30 second crank and see if it works.

Yes, new oil and filer.

Checked the oil pressure sending unit and it looked fine.

The pump itself seated with no problem and I double checked the torque on those bolts.

I definitely put the o-ring on, but I had a heck of a time getting that last pick-up tube flange bolt in, which makes me wonder if the o-ring was damaged with all the fiddling around.

(Regarding the cloudy oil thing I mentioned, I don't think it is related to this problem. When I pulled the heads a good amount of coolant went all over the place and probably ran down the oil passages into the pan, which made the new oil cloudy (?). They have been sitting together in the pan for a couple of weeks now.)

 

[Eric M]

One follow-up question: I did install the high pressure Melling pump. Might this one be harder to prime by just cranking the motor?

 

[Hamfisted]

One follow-up question: I did install the high pressure Melling pump. Might this one be harder to prime by just cranking the motor?

No. They're about the same as far as that goes.
If you have the Expy up on ramps don't be surprised if your fuel pump inertia cutoff switch got triggered and you have to reset it.



.

 

[Eric M]

I did a few 30-40 second cranks and still no pressure. So, I pulled off the filter for a second time and, again, it was filled with oil and a good amounted of oil came pouring out of the orifice on the oil filter adapter.So, some oil was moving around in there.

I know many of you will disapprove of what I did next, but I started the motor to see if pressure would rise. It only ran for 2-3 seconds before I shut if off. But the pressure gauge didn't budge and the "low oil pressure" light stayed on.

At this point is it even worth hooking up a gauge to the oil pressure sensor orifice, or is that just a waste of time? I'm thinking I should check power to the oil pressure sensor plug too.

 

[Hamfisted]

Did it sound and run normal ? No clattering from the top end ? It'll clatter if those valve lifters don't get oil pressure. Either replace the sender or hook up a manual gauge to confirm what kind of oil pressure you're getting. It's a 1/4" NPTF fitting.


Oil Pressure Test Kit on Amazon

Motorcraft Oil Pressure Sending Unit at Rock Auto



.


.

 

[Eric M]

Yeah, the motor sounded exactly like it should, no unusual sounds at all. Thanks for the recommendations. I'll buy a manual gauge and we'll see what happens.

 

[Hamfisted]

Sounds like the sending unit is bad ? Did you ever have any issue with oil pressure indications before you did the rebuild ?






.

 

[Eric M]

Never any issue with oil pressure lights before rebuild. No codes are being thrown either. I just happened upon a video and it appears that this priming problem is fairly common. I am going to take a pressure reading (when my gauge arrives) and then use the priming method suggested in this video:

Melling m360hv prime after no oil pressure after install- unedited but valuable info if you need it

What I had to do the prime a Melling m360hv oil pump on a 5.4 3v Expedition. Sorry I am not a video producer so this a bit rough but wanted to get this info...

www.youtube.com

 

[craig72]

I am getting ready to change my oil pump on my 4.6 Romeo as part of a timing job. I saw the same video you mentioned above and even have it bookmarked. I'm interested to know what you find out.

 

[Vincent Vega]

@Eric M This is just a thought but the oil sending wires may have gotten a beating as you were removing the LH valve cover, and then removing and installing the power steering pump. Oil pressure sending wires go right through there. Oil in the filter and no top end clattering while it was running suggest you might have oil pressure. I recall being worried about how many times I pulled and poked those wires while I was doing my timing, so just something to consider. Will be figured out or confirmed when you test using an external gauge that @Hamfisted suggested.

 

[Eric M]

@Eric M This is just a thought but the oil sending wires may have gotten a beating as you were removing the LH valve cover, and then removing and installing the power steering pump. Oil pressure sending wires go right through there. Oil in the filter and no top end clattering while it was running suggest you might have oil pressure. I recall being worried about how many times I pulled and poked those wires while I was doing my timing, so just something to consider. Will be figured out or confirmed when you test using an external gauge that @Hamfisted suggested.

You are right about the wires. I did come into contact with them many times during the rebuild. I will need to inspect them more closely and check for voltage.

 

[Eric M]

I am in the process of checking the oil pressure sensor wires and the sensor itself. I have a couple of questions:

1. The sensor has one blade that inserts into the plug. How can I test to see if current is reaching the sensor if there is only one slot in the plug? I tried putting one lead from a multimeter into the plug slot and the other lead to ground, but that did not work. I also tried using a test light, but same result. Perhaps I need to crank the motor while testing (?).

2. I bench tested the sensor for continuity. The sensor is in the open position. Is this correct? Some sensors start in the closed position and then open up when the motor is running. So, the question is whether the sensor for this particular vehicle needs to be in the open or closed position when at rest. This will tell me if this sensor is bad or not.

I'll keep Googling this ....

Thanks for any assistance you can offer.

 

[Hamfisted]

With the key in the RUN position and you ground the harness plug, do you get a normal oil pressure indication on the gauge ? The sender should close circuit between 5 -10 psi of oil pressure. Cheap enough just to replace the sender.

Single Pin Oil Pressure Switch Test Video






.

 

[Eric M]

Thanks for the diagram. I will resume testing when my new sender arrives tomorrow.

 

[SafariGoneWrong]

I couldn’t get pressure by cranking the engine after installing a high volume Melling pump during a full timing job along with roller followers and lash adjusters. I took the chance of starting the engine and got pressure within about 5 seconds. Risky business but no ill effects 20K miles later.

 

[Eric M]

I couldn’t get pressure by cranking the engine after installing a high volume Melling pump during a full timing job along with roller followers and lash adjusters. I took the chance of starting the engine and got pressure within about 5 seconds. Risky business but no ill effects 20K miles later.

Good to know. I may be going this route myself if the manual priming doesn't work out.

 

[Eric M]

Things just keep getting weirder.
I used this oil pressure test kit (thanks toHamfisted for the recommendation) and it worked great, I think. I used this kit to prime the pump. It comes with everything you need for a DIY pump primer except the pump itself. Just remove the gauge, insert the appropriate fitting in its place, and connect whatever pump you have on hand. I used a pump similar to this one. One hose in the oil jug, the other hose connected to the fitting on the gauge hose, whose opposite end is inserted int the oil pressure sensor orifice.

After the priming, and with the manual gauge once again hooked up, I cranked the motor and the gauge got up to the 20 psi range. So, I figured everything was A-OK. I ran the motor and the pressure rose to 90 psi and stayed there.

So, I figured I was basically done with this project from hell. Wrong again. I put in the *new* oil pressure sensor and connected the wire. Started the motor, which sounds great. After ten minutes of idling, the "hi temp low oil" light comes on. There is plenty of oil in the motor. Also the "Low oil Pressure" light has never turned off and the oil pressure gauge has not moved.

So, it appears that my oil pressure is quite high, but there is clearly some issue. Is it possible that I lost the prime during the time in which I unhooked the gauge and installed the new pressure sensor? Seems unlikely.

Is the high volume oil pump causing the sensors to malfunction, and in reality everything is fine?

This car can truly drive a man to drink....

 

[Hamfisted]

Can you take a jumper wire and ground the sender's plug then turn the key on and see if the oil pressure gauge goes to the middle and the oil pressure light goes out? This will at least test the circuit and the instrument cluster gauge. If you look into the oil fill cap opening into the motor do you see oil on the parts? Or do they still look dry? What brand and part number pressure sender did you use ? That "High Temp Low Oil" references oil pressure, not oil quantity. So it's all oil pressure related on your issue.




.