'88 ranger 2.3 no oil pressure

Shran · Nov 9, 2014

Help. I am working on a 1988 Ford Ranger with a 2.3. Yesterday, I replaced the plugs, wires, cap, rotor,valve cover gasket, and installed aftermarket temperature and oil pressure gauge set. I also changed the oil in the truck.

Today, I drove about 20 miles and everything seemed to be fine. I had about 40 psi oil pressure at highway speed,and it suddenly just dropped to zero. I figured at first that it was just a bad gauge, because that has happened before. About 2 miles later, it started making a lot of noise so I pulled over and shut it off.

the engine still is full of oil, and is at the proper level.I don't understand what happened here. None of the things I fixed should have had any effect on this - any clues?

rfl · Nov 9, 2014

What kind of a noise? Did the engine temp rise?

If it were not for the noise then I would be guessing the gauge or sending unit. But, since you have noise and did change out the valve cover gaskets it does call into question what kind of a mess you may have been working in. Deteriorated gaskets and dislodged engine sludge can both get pulled into the oil channels and cause a blockage. Seems rather on the edge, but given what you have stated that is where I would look unless the noise is completely unrelated.

RonD · Nov 9, 2014

Oil pressure sending unit is not leaking, it is on the main oil passage.

Could new oil filter be clogged/bad?

Oil pump runs off a timing belt gear so engine would have shut off on it's own if belt broke.

If possible remove oil pressure sender, disable spark(no start) and crank engine, with bowl under sending unit hole, see what kind of flow you get.
Then remove oil filter and repeat, if you get flow out of filter housing and not sender hole then filter was the problem.
If no flow from filter housing then oil pump or gear is bad.

My bet is bad oil filter.

Shran · Nov 9, 2014

The noise it is making I would describe as a really loud, fast lifter tick.

The engine did not get hot, it was sitting at 190 when I shut it off, as read from an aftermarket gauge.

Filter used was a Motorcraft FL-1A

I was very careful when I removed the valve cover. I even vacuumed out gasket chunks and debris before and after changing the gasket.

Bad filter: if the filter was bad, wouldn't the bypass valve just open up?

Here are a couple more things. I let it sit for about an hour while I went home and got the car trailer. When I got back and started it, I got about 10psi oil pressure for a few seconds while I loaded it on the trailer. The valvetrain noise was not quite as loud.

When I got home, I started it again and it built up about 20psi pressure and the noise quieted down a lot but not completely gone. I let it run for about 20 seconds or so and the pressure started dropping. I revved up the engine to about 2500rpm and it did not increase at all.

RonD · Nov 9, 2014

Filter can be made on a Monday

And where is the bypass valve?
In the oil filter

That is just my best guess since it is something you changed, and it can block oil flow

And from your above description this is looking more likely, that or pick up screen is full of debris, what did the old oil look like in the drain pan any debris?

Shran · Nov 9, 2014

I changed the filter. The old one had very little oil in it. Cranked it over with no filter for about 2 seconds and did get some oil that came out. Now it is not making noise anymore but is not holding much pressure, maybe 15 at idle and it drops to 10 or so at 2500. Perhaps the fitting and plastic line to the gauge is clogged?

Shran · Nov 9, 2014

Also the oil that was in the old filter was very dirty with streaks in it, but the oil I got out of the engine looked good.

RonD · Nov 9, 2014

The Ford oil pressure switch that was on it was set for 6psi, as long as pressure was above 6psi oil gauge stay at 1/2 or just below it.

General rule of thumb for oil pressure is 10psi per 1,000rpms, but it is a curve so there is less pressure at higher RPMs, i.e. not 50psi at 5,000rpms, maybe 30-35psi, 700rpm idle would be 7-9psi.

Oil pressure means there is TOO MUCH OIL
The oil pump pushes oil to the filter and then out to the main oil passage and then to the bearings, oil pressure sender is on the main passage, oil flows to smaller passages and to the bearings.
If there is more oil coming in than the bearings can pass, then the oil backs up, pressure builds up in the main passage, that's the oil pressure you see, there is too much oil.
Because of gravity you need above 5psi for the valve train to get oil, depends on the setup but usually above 5psi is OK, you start to get ticking valve train noise below 5psi.

The 40psi at 2,500-3,000 RPMs sounded high for what I assume is a medium to high mile engine.
20psi would be more like it.
High oil pressure causes issues as well, 8-30psi is an acceptable range for most engines

Shran · Nov 9, 2014

Hmm interesting. I guess I'll drive it around and see what happens. The drop in pressure still seems off to me, I just have never seen a drop or no change in pressure with an increase in RPM. Seems like usually when you crack the throttle, you get an almost instant, significant increase in pressure.

Also the clear plastic tube leading to my gauge has a lot of air bubbles that don't move much.

RonD · Nov 9, 2014

Did you remove the sender and crank engine, could have some "gunk" in the hole

Or remove the tube on the back of the gauge and crank the engine over, clear out the bubbles, put end in the bowl or bucket

Yes, oil pressure should increase with RPM, the volume the pump sends increases with RPM but the oil the bearings can pass/use doesn't increase as much.

Shran · Nov 11, 2014

I have the day off today so I pulled it off the trailer and messed with it. I started it and let it run for about 20 minutes and drove it around the block. It sounded normal, no ticking or weird noise, but the oil pressure gauge never moved off zero.

After the run around the block, I let it run for a bit and ran the snowblower for a bit. While I was doing that, it started ticking loudly again...still no oil pressure.

So where do I go from here? I am thinking I should pull the engine and have it gone through or buy a crate motor. Crate motor is sounding like a better option, one of the local machine shops wants $2600 "worst case" to rebuild my block...... crate engine from O'Reilly is $1300....

Automan1988 · Nov 29, 2014

Not sure if you are still having this problem or have decided to go another route, but I just got done working on a 91 2.3 that took well over 30 sec. to build any oil pressure. I had read that oil pan gasket was known to rot out and plug the pick up screen. The engine had to be removed to get the pan off, but when I did the screen was plugged almost solid. Installed a new screen and pump and now have instant and good oil pressure. Just another thing to look at.

Shran · Dec 4, 2014

I pulled the engine and am having it rebuilt. I found a machine shop in town that will rebuild it for $1300, assuming the head, crank, and block are usable.

Lot of money to drop on an old truck but the body is in really good shape, and I already have $1500+ into it so might as well fix it.

I thought about putting a newer 4 cylinder into it since they seem to be more common in the junkyards but the wiring conversion is more than I want to tackle right at the moment.

03ranger4x4 · Dec 5, 2014

Damn, 1300? You probably just could have bought a reman long block and called it a day for around that. You could probably save yourself about 7-800 bucks and rebuild it yourself if your handy. Master rebuild kits for these 2.3s are dirt cheap, often 350$ sometimes less including pistons, some kits even give you a new cam and lash adjusters.

I know the feeling, I bought my 88 ranger in July and already dropped over a grand into it to fix all the hidden problems with it when I got it. A payed a grand for it. So two grand for a gutless, beat up, rusty clunker. At least it's reliable now though. And entire cooling system and head gasket later.

Shran · Dec 5, 2014

03ranger4x4 said:
Damn, 1300? You probably just could have bought a reman long block and called it a day for around that. You could probably save yourself about 7-800 bucks and rebuild it yourself if your handy. Master rebuild kits for these 2.3s are dirt cheap, often 350$ sometimes less including pistons, some kits even give you a new cam and lash adjusters.

I know the feeling, I bought my 88 ranger in July and already dropped over a grand into it to fix all the hidden problems with it when I got it. A payed a grand for it. So two grand for a gutless, beat up, rusty clunker. At least it's reliable now though. And entire cooling system and head gasket later.

None of the parts stores can get the right long block and they are right around $1500 too. It seems that 4 plug heads and blocks with a distributor hole are getting very hard to come by.

The $1300 is literally everything though, new cam, valves, pistons, seals, machine work. The local shop that is "well known for quality sprint car 2.3's" wanted $2600 to go through it :shok:

F that!

I would have just had them do the machine work and put it together myself but I have Christmas coming up, out of town at least 4 days in the next couple weeks for work, kids activities, and so I am really short on time.

'88 ranger 2.3 no oil pressure

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