I have a 1999 ford e-250 v-6. i had the oil changed at a firestone where i always have it changed. a week later the oil pressure started dropping to 0 at idle it go back to normal while driving. i replaced the oil pump and it didn't fix the problem. any suggestions???

First, is it a 7.3 power stroke or is it gasoline ?

Simple check first. Check your oil and make sure it is reading correctly on the dipstick. If it is low then add oil and watch everyday to see if the oil drops. If it is dropping quick enough to notice in a day or two then you have a leak somewhere an need to find that. A pressure test may need to be done as well to make sure oil pressure is high enough.

Try removing the cooling fan and shroud, unbolt the engine mounts and try to jack up the engine until you have clearance.

The oil warning light is telling you the oil pressure has dropped below 10psi which does not always mean the oil level is low.
When the oil pressure drops, the power for the fuel pump is cut for safety reasons. You would not want the fuel pump to keep going if you were in a wreck and the engine stopped but the key switch was still on.
It could be a faulty sensor, or you really could be loosing oil pressure.
If the light comes on again, you would need to have the pressure checked with a mechanical gauge.

Oil Pump or cam bearings

either you have an oil leak somewhere... or your oil pump is going bad!

TPMS sensor stands for Tire Pressure Monitoring System. Basically there is a pressure sensor in each wheel. It sends a signal to a computer and tells you if you have a low tire. This was probably not the dealerships fault as they usually check your tire pressure when they do a oil change. You should check your pressures and fill any tire that is low. They probably run at 32psi on your vehicle but you can check inside your drivers door on the sticker, that will tell you what they should be set to. If it is really low you might want to take it in and have it checked you may have picked up a nail or something along the way. Also that light will come on if a tire is too much over inflated. Good Luck

It may be a coincidence but try replacing the oil pressure-sending unit if it does not change try changing back to the original oil

The High pressure oil pump is going out.. This is the oil pump that operates your injectors .. when the oil gets hot this oil pump puts out less pressure and will not let the injectors operate right . when the oil is cold in the morning it will have more oil pressure because of the oil stiffness. later after ran a while and it gets warm it wont operate your injectors.. you can also change the oil to a heavier oil but this will only temp fix it.. .. good luck and this is what is wrong with it .. not sure what these cost but they are located at the rear of the engine on top .. on the 6.0 if i remember right not inside the engine.

Unhook the battery for about ten minutes... that should take care of it..


Robert

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