Oil pressure up and down on 93 2.3L

[Billjr]

Hi all,
I started having a problem with my 93LX 2.3L. I was driving and the engine started mild pinging and smoke was coming out of the back as I drove home. I then noticed the oil pressure gauge was down to 0. Like the key was off. I drove the 8 tenths of a mile back home and parked the car. Then went in to search craigslist for a new/used motor as I figured mine was cooked. It has 136000 miles on it with no problems until now. I bought it with 118000. So yesterday I was going to check out a motor, and I went to move the Mustang out of the way to make room for my trailer and the car had great oil pressure again. I let it run for 20 min. then revved it to 3000 rpm and no smoke. I let it run 10 min. more and the oil pressure dropped to 0 again and the car smoked again. I shut it off. Five minutes later I started it up again and the oil pressure came right up. That was yesterday. I had changed the oil and filter about 50 miles ago. So I know its not a clogged filter. Today I removed the valve cover to check for clogged oil drains. Everything is clean and open. The oil is at proper level according to the dipstick. Now I'm lost. Anyone got any ideas or similar experiences? Thanks in advance.
Bill

 

[Delray Dude]

Had a very similiar issue with my '93. Had oil pressure, then didn't, then did, then didnt, then really didnt.

What it was: with the DIS system, you don't have the distributor anymore, so the guys took and chopped off the distributor and made a plug and the oil pump drive that sticks down and is driven off the side shaft. it is located on the drivers side - behind the alternator and below the intake. You can see that plugs into the block and there is a small bolt that clamps the thing down. Undo the bolt and it may take a little effort to get it out the 1st time - but it pulls right out. look at the gears on it. Mine were stripped one one side and what happened was that it would land on that area sometimes and would stop spinning the pump. I went to the junkyard and got another one off a another 2.3. Rangers or Mustangs will have it. Put it in and ran fine for a bit - carried a spare in the trunk. It wore out in a week and back to the same deal. It turns out the actual shaft had a bad spot on the gear and it would chew up the oil pump gear. had this been in my 88 with the distrib - it would stop the distrib and the engine wouldn't run.

So, I'd pull the oil drive gear and look at it to see if it's galled up on an area of the gear. if so, chances are the shaft is got damage and you can (for the short time) put in another drive gear, but you will need to get another shaft and drive gear. I got one out of a newer Ranger - 1996 I think. Got both the shaft and gear and over 30k miles have not had a problem. Obviously you will have to remove the timing belt to replace the shaft and you will need a nice phillips screwdriver that has a provision to put a boxed wrench on it to help remove the shaft retaining piece. It's in tight and you need lots of pressure on the screw both holding the phillips into them and rotating the screw loose - once broken free - easy to replace.

I recommend checking yours 1st by pulling the gear and looking. If it is bad - then practice pulling at the junk yard. before you cut the donor's timing belt - always a good idea to break the timing gears bolt free 1st. once you get it all loose - (pull the oil drive gear 1st) the shaft pulls out from the front really easy.

 

[Billjr]

Thanks I'll look into that. but... I have oil pressure it seems until the car heats up [20 min] then it goes up and down a little then goes to 0. Also that is when the smoke starts. I guess if things expand in the pump drive to the point they no longer mesh, this is possible. Let me know what you think Delray dude.

 

[Delray Dude]

Could be just that - it might be just worn enough that it catches when cold and doesn't once warmed up. Hope whatever it is, it's an easy find. But I'd pull the oil drive gear 1st - thats a fairly easy check and you don't destry any seals or anything to do it. I think the 1st time i used a small screwdriver on the side to get the thing poped up and then it pulled right out.

 

[Billjr]

Got the gear out with little trouble except for having gorilla hands and couldn't get to it easily. It appears worn but intact. While it was out I spun the oil pump drive/6pt hex shaft with a drill. Got little to no pressure at first so I reversed the drill thinking I might be going the wrong way. Still nothing. Switched back to forward and got good pressure. Oil was coming out of the cam lobe holes in a nice stream. I had the valve/cam cover off to check for clogged oil drains. The inside is very clean. I read on another site that the gasket sealer or gasket on the oil pan breaks down and little pieces will eventually clog the oil pump pick up screen. Maybe when I reversed the flow it cleaned the screen a little. I did have pressure when the car first started as I said in my OP. Maybe after it warms more particles move around and clog the screen. Then after shutting it off the oil drains back out the pick up tube and flushes some of the particles off. Not sure but after I check the oil pump drive shaft behind the timing belt, the oil pan will be the next thing to come off. Let me know what you think Delray.

 

[Delray Dude]

could be that there was some crap in the pickup and was blown out on the reversing of the pump. might drain oil in a clean catch can and see if it's contaminated - if not - dump it back in the engine.

 

[Billjr]

Hey delray dude,
I finally got some time to work on the car again and it is finally warm enough to work without frostbite. I pulled the timing belt cover and and belt. Then the oil pump drive gear. I have no phillips screw. I have three 10mm bolts that seem to hold the auxiliary shaft in. I can't get the auxiliary shaft to come out. It moves about a 1/16" only. It turns side to side about an 1/8". What do you think I need to do now. Thanks

 

[Delray Dude]

IIRC: the 3 bolts hold the cover and the shaft seal to the shaft. You will need to carefully pry that off to get to the thrust plate that holds the shaft in place - that is held on by the 2 phillips head bolts.

after you get the plate removed the shaft will slide out very easily.

 

[MustangLX-5.0]

I remember my '88 2.3 had that problem. Had solid pressure when it was cold, but the engine was hell noisy. Made a lot of clak/clik knocking noises. Was worse when it was colder and quieted down when it warmed up. After it warmed up, pressure would eventually drop below the bold white line just above the red line. The pressure was jumpy. When the engine had been running long enough and it was fully warmed up, the pressure would sit just above the bold white line at the bottom at idle. If I just increased the idle RPM's so slightly to around 1000 - 1400 RPM's the pressure gauge would drop like a bomb below the red line... it never smoked or anything. once it got above 2000RPM the pressure shot way up . Never knew what the problem was. The only thing that smoked was the radiator from the leak.

Sorry to hijack your thread. carry on .. just something that came across my mind. Haven't owned the car for a long time.

 

[clash69]

Been there done that, it is going to be the oil pan gasket breaking down and clogging screen, I have done 3 in last 2 years