oil gauge early warning sign?

[RodGod]

hey everyone i just found this forum site today, glad to see this forum is still alive. i just purchased an 02 explorer xlt 4.0 - V6 Its been well taken care of over the years, i believe the guy who owned it b4 me towed a lot because theres an electronic brake control installed, anyways, i dont know what the issue is with my oil gauge. everytime i start the truck, while idling to warm it up the gauge reads Low and the red indicator "CHECK GAUGE" comes on. Then after about a minute or two something clicks or skips in the engine and it goes back to normal, with the needle in the middle for normal oil pressure, as well as the indicator light goes off. I just want to know if anyone knows whats happening. My mechanical knowledge experience is beginner at best. thanks

 

[Mbrooks420]

If the motor makes a rattling sound when you first start it you most likely have broken timing chain tensioners, and possibly have plastic pieces of them clogging the oil pickup.

I know the oil pressure gauges on earlier don’t actually read a value, they are either on or off. I assume it’s the same on the third gens.

I’d want to verify it actually has a low oil pressure on startup and work from there.

The previous owner probably had gotten an estimate on fixing this, and now you know why they decided to get something else.

 

[LMHmedchem]

An analog oil pressure gauge is pretty reasonable,

PITTSBURGH AUTOMOTIVE Engine Oil Pressure Test Kit ($30)

This will let you read the actual oil pressure and let you know if there is real pressure loss of if the sensor is bad. There are allot of videos out there on how to use these. Even the Motorcraft sensor is only $8 or so if you need to replace it. If you do replace the sensor, I would also replace the oil filter adapter gasket at the same time unless you know it has been changed out recently. These gaskets always start to leak at some point.

As Mbrooks420 suggests, it is likely that there is an obstruction to the oil pickup tube which can be broken plastic or sludge from oil that wasn't changed often enough, or oil/air filters that weren't changed often enough. When the engine oil gets hot enough it thins out and can move more easily around a partial blockage. You could drop the oil pan to check if you would rather wade in than buy a meter. Sometimes you can clean out or remove the obstruction and sometimes you need to replace the pickup tube.

If there is chain rattle on startup then you need to address your timing chains immediately. This can't wait on the 4.0L v6.

LMHmedchem

 

[RodGod]

An analog oil pressure gauge is pretty reasonable,

PITTSBURGH AUTOMOTIVE Engine Oil Pressure Test Kit ($30)

This will let you read the actual oil pressure and let you know if there is real pressure loss of if the sensor is bad. There are allot of videos out there on how to use these. Even the Motorcraft sensor is only $8 or so if you need to replace it. If you do replace the sensor, I would also replace the oil filter adapter gasket at the same time unless you know it has been changed out recently. These gaskets always start to leak at some point.

As Mbrooks420 suggests, it is likely that there is an obstruction to the oil pickup tube which can be broken plastic or sludge from oil that wasn't changed often enough, or oil/air filters that weren't changed often enough. When the engine oil gets hot enough it thins out and can move more easily around a partial blockage. You could drop the oil pan to check if you would rather wade in than buy a meter. Sometimes you can clean out or remove the obstruction and sometimes you need to replace the pickup tube.

If there is chain rattle on startup then you need to address your timing chains immediately. This can't wait on the 4.0L v6.

LMHmedchem

after i let it warm up for 2 minutes or less when its not as cold out, oil pressure goes perfect. a couple times i have been in a rush and just started driving and the gauge goes back to normal. when i open up the oil cap there does seem to be some golden/yellowish sludge build up 3 inches down. i appreciate the insight guys.

 

[Mbrooks420]

I don’t think there is a “perfect” on these gauges. If you have more than 5-10 psi it reads in normal zone. If it’s less than the threshold it reads zero. It may as well be a light.

 

[LMHmedchem]

when i open up the oil cap there does seem to be some golden/yellowish sludge build up 3 inches down.

What does the oil look like at the dip stick? Also, check you coolant to make sure there is no oil in it. If there is any oil in the coolant, it will sit on the surface in the reservoir. I would clean out the yellow sludge and see if it comes back.

LMHmedchem