Loss of oil pressure.

[trooperholman]

I have a searched on the forum a little and online for the issue I have been having. So in December I loaded up the sport with the pup to go have some fun snow time. I get about 5 miles away from home and I see the oil pressure gauge dancing up and down. I pay attention to it but I know my rig has a few gauges that aren't perfect(temp). The pressure drops to 0 so I pull over to the closest gas station to check fluids. The beast was a tiny bit low on oil so I added half a quart. I fired it back up and the gauge is still back at 0, so I decided to cancel the trip and get back home asap. I drive the few miles back home and the motor is starting to make noise and I'm getting worried it maybe the exploder I call it. Now when I'm back home I turn it off and it still has no pressure and now sounds like a sweet diesel truck!

I let it sit till this weekend when I decided on taking the good tires and put them on my other rig. I fire it up and drive it to the next door tire shop and when I did the gauge was 0 pressure again with engine noise then right when I put it into gear the pressure jumps to normal and no more noise. I get it to the shop and its running quiet and no issues(surprised me) and after the tire swap I drove the beast around through our snow storm about a mile or so and still great pressure and no noise. I let it sit till today to fire it up and then no pressure again with slight noise then when put into gear the pressure is back and its running smooth.

I know the gauge isn't the most accurate but I'm kind perplexed on why the loss of pressure is happening-now intermittently. Any suggestions would be great.

 

[Turdle]

Most likely you have timing chain component fragments in the oil clogging the oil pickup.when you turn off the engine they fall off, and everything is good ( well, not good but gauge says good) until they get sucked back into the pickup screen.

2nd off chance would be a clog of some sort in the oil filter itself. I recommend dropping the oil pan to have a look.

 

[trooperholman]

Most likely you have timing chain component fragments in the oil clogging the oil pickup.when you turn off the engine they fall off, and everything is good ( well, not good but gauge says good) until they get sucked back into the pickup screen.

2nd off chance would be a clog of some sort in the oil filter itself. I recommend dropping the oil pan to have a look.

Thank you. I'm going to bring it to the mechanical shop I use here at my body shop. Were gonna do an oil change and a real pressure check.

 

[BruceExploder]

I'm not saying to do this but I ran a half a quart of marvel mystery oil minus a half quart of oil and it cleared up oil pressure issue I had. I think the pan may have been clogged.

 

[donalds]

Drop the pan look for plastic in the oil pickup as @Turdle says

 

[ranger7ltr]

Did I miss which engine your truck has in it? If it is the SOHC then plastic fragments in the oil pump are probable; if it is the OHV not so much and the engine still starts and runs... If you drop the pan in either case I would recommend a new oil pump and oil pump pickup in hand to replace what is in the engine...And if the pump does have plastic bits in the pickup take a look at the oil pump driveshaft...And have it as a replacement as well...It can twist and break...

Hopefully it is a RWD truck... The oil pan drops out the bottom easily enough...Did the same on my 99 Sport with OHV when I bought it with no oil pressure...Mine was completely sludged and the pan was as well...New oil pump, new oil pump pickup, and new oil pump driveshaft later I had 60 psi of oil pressure...

 

[koda2000]

If you have the SOHC V6 engine an oil change should not be your first though...

Broken pieces of plastic from your timing chain components are a good bet. Remove your lower oil pan and check for pieces of tan plastic around the oil pickup. If found remove them and clean the pick-up screen.

BTW - If you find the broken plastic pieces in the oil pan you're engine is living on borrowed time, because the timing chains will eventually jump and you'll bend valves. Does your engine rattle and/or make noise at start-up?

The oil pressure switch also can cause false no pressure readings, which bounce the oil pressure gauge's needle so hard it can get below its stop peg. Hopefully this is your issue. Many of my Explorers have suffered from this (V6's and V8's).

 

[CDW6212R]

Given the engine noise, there will probably be some evidence in the oil pan that points to the problem. Plan for doing work on that SOHC 4.0 valvetrain if that's what it has.

If not it's likely a bad oil pump. But note the oil pressure sensor is only and ON/OFF sensor, it simply shows any pressure as normal on the gauge. The older Fords all had a large pressure sensor, and with it a variable display reading on the gauge. The newer models just use the simple small sensors. Check the wiring connection to that, in case it's off or damaged. Good luck,

 

[BruceExploder]

Now my gauge is acting up again. Guess I'll drop my pan.

 

[koda2000]

Now my gauge is acting up again. Guess I'll drop my pan.

If there's nothing found in the oil pan (and the pick-up screen is clear) it could be your oil pressure switch (it's a switch not a "sensor") is bad, but while you're replacing it you might want to install a real oil pressure gauge to test your actual pressure. Ford's OP switch causes the dummy gauge on the dash to read normal (center of gauge) if you have as little as 5 PSI of oil pressure. A real gauge should read at least 30 PSI on a cold start, should vary between maybe 5-7 PSI at warm idle and increase around 10 PSI for each 1000 RPM up to around 35-40 PSI. I installed a heavy duty oil pump in my '61 T-Bird 390 and it made so much oil pressure it almost exploded a cheap oil filter and I had to switch to a higher quality (thicker steel) filter. That oil pump made about 75 PSI on 30 weight oil at cold start.