What is the minimum oil pressure before the light actually comes on.

I have an 87 BII 2.9 and some times the light flickers, but never stays on.
But this is only at low rpm (idle).

No tapping, clicking or higher than normal engine temps, and I don't have low oil.

I messed with it a bit today after it warmed up and
I could only get it to do it if I let the clutch out real slow almost stalling the engine, and dropped the rpms to about 900, usually idles at 1000. couldn't get it to do it like it did when I was idleing earlier today.
It was flickering at normal idle then, if 1000 rpm is normal.

Is this normal? , I don't know the minimum pressure to trigger the idiot light.

I'm getting ready to install an actual "pressure guage",
Guess that's a good starting point.

Also going to change the oil and filter, could be clogged also.

Lifting the motor to change the oil pump is not really an option right now.
Should I flush the engine with some cleaner ? I've heard yeah and nay on that idea. And NO FRAM !!!

any other tips ?

Best oil type?

Thanks

Also, someone posted one time about cleaning the screen through the drain pan, is that possible ?

 

I would guess the light comes on around 10psi.

 

id say its your oil pump screen, the thing on the oil pump.

i really dont know why they have that on there though? Why not have the suction line form the oil pump run through the oil filter first so the screen clogging thing will never happen.

Try putting thicke oil in, it may help keep the oil pressure up for now.

i noticed with my 87 bronco II when i first turn the key, the oil pressure light dosent come on but the battery one dose. Yet if the engine have been started then shut off or stalled it comes on when the key is on. The eninge has to be started in the past like i guess hour for the light to turn on when you turn the key on but not start th engine. Is this supposed to happen, anyone?

 

The pickup screen is on there so you don't pick up any hard parts / shavings from the oil sump if anything fails (bearings, etc.). That would completely render the pump useless...

The oil pressure light switch actuates the light @ 10-15 psi, if I remember right (I believe it's closer to 15). Usually, the light isn't on when you turn the key on when it's cold because the oil has leaked back down into the oil pan / sump, and this sensor needs direct pressure / contact with the oil...

Warm idle rpm is supposed to be 850 rpm for a manual tranny and 900 for an auto, if I remember right. Anything above that after warm-up means that the idle stop is not set right and/or some of the sensors are going out or giving bad information.... OR, you might have a vaccuum leak.

The sensor might be going bad / or the wrong one, or your engine is starved for oil. The latter is a big problem with the 2.9, mostly due to the oil pump pickup clogging. Engine idle is ... quirky at best with the EECC-IV system... from what I've experienced with my '87 BII XLT so far. I just don't have the time or money to replace all the sensors and tinker right now... and it's still starts and gets me around without fail... so... until it dies... *shrug*

 

Check the wire that attaches to the sending unit. If it has a bare spot on it and it touch metal it will ground and make the light come on.

 

I know what you mean, but why not have the suction line from the pump run right from the pump to the screw in oil filter then have a pipe from the to the oil pan. this way theres no need for the screen sence the pump sucks right out of the oil filter. Also if there chunks clogging that from blown bearings and/or engine id just get a new oil pump weather or not i really needed it, cuase no oil is a cuase of bad bearings and if im doing the whole motor why not?

 

Hey.
I kind of have a similar problem. I don't have the light, I have the gauge. Start the car, warm it up-pressure nice and high. Blip the throttle-no reaction. As soon as I get to the third gear. it starts dropping a little bit. If I go in the third gear up to 40mph, it drops almost into the red zone. Interesting thing is that it is not so much affected by the rpm but by the load. For example, I am going in 4th gear 40mph. Pressure is normal. I floor it. As soon as I get to the 50mph, the arrow is far into the red zone on the pressure meter. I switch gear into the 5th, and the pressure slowely comes up.
Oil and filter were changed recently.

Any ideas?

Thanks,

Klim
P.S. Spiritwild, I don't want to hijack your thread. Just think we have a similar problem and it makes sense to post under the same thread

 

It is always a good idea, especially on older vehichles, to do an engine flush when you change the oil....

Mulik, what it sounds like to me, is that your oil pump is wearing out and possibly the prop shaft from the distributor... unless, of course, you have blockage somewhere causing oil flow problems

Another issue might be voltage... your alternator/battery might be partly to blame as well (loaded engine, voltage drop or surge in the charging system)

 

Thanks.
Ill do the engine flush next time I change oil.
Wierd thing is this, for example i am in 4th gear doing 35. Pressure is normal. I floor it, and get to 50mph. The pressure is in the red zone. I keep doing 50 mph steady(leveled surface) for 5 mins-the pressure slowely rises and shows a very good pressure...
This is just perplexing...

Thanks again,

Klim

 

Light comes on right about 4 PSI.. EEEK I know. Best thing to do is install a mechinical oil pressure guage. Couple hours saves a lot of uncertanty.

 

Will an engine flush help or would it break to much crud loose on an older engine not trying to hijack the thread but I am curious?

 

Some people will say an engine flush will help, others will say it is dangerous. If the engine has a lot of crud build up in the crevices really not bothering anything and you have it flushed, there is a good chance that will all break free and the flush may do more harm than good.

So it is really your call. Most of the time the pickup screen on the oil pump gets cruddy. But when I pulled my oil pan of my 2.9 with 130K, it has absolutly nothing on it. Suprised me