Mechanic question

I have a 2011 F-150 that has been giving me problems the last few weeks. 170,000 miles.The truck seems to run good but keeps throwing truck problem read outs on the dash panel.

Fixed a couple problems by replacing ( 3) NAPA alternators in the last months finally with a ford OEM alternator. Also replaced the ECM module. These repairs seem to have fixed a few problems.

At least it has fixed the dash alerts of low voltage and the check engine indicators so far. Only have had the truck back from Ford garage a few days now. Time will tell if it has fixed those for good.

The Low oil pressure dash read out is flashing now once again. We have changed the oil pressure sensor twice in the last few weeks. The oil level is good in the truck but the truck has been running low on oil occasionally but no smoke from exhaust. Just is low every couple of weeks it seems. No significant signs of leaking.

So what else could be causing this low oil pressure indicator to read on the dash.

Ford gauges for oil is not a gauge. Glorified idiot light. A lot of people did not understand fluctuating oil pressure,(rpm,temp ,etc) so ford put in a on off gauge. If you have a light or a gauge, put a mechanical gauge to verify pressure

It may actually be low oil pressure causing the light to come on. The next thing I wuld do is hook up a mechanical gauge to the oil pressure sending unit port and check oil pressure at a hot idle.

Yep.

I had 300k on an F-150 and when that light took to flashing I should have done something. The pump went down and I seized it up for good so beware

Checking the oil pressure with an actual gage is a must.

Other than that , you may have some electrical gremlins causing alternator charging issues. Common things to look for or to have your mechanic look at - bad ground , bad fusiable link coming off battery. Short in wiring. If your oil pressure is truly good , bad electric problems can also cause the oil pressure lamp to flicker too.

Bob, check your starter too. It might be staying on. I had an 88 Nissan pickup that would always go through alternators. Replaced the starter which fixed the issue.

BJ

If your engine is low on oil every couple weeks, that oil is going somewhere. If there is no visible external oil leak, it is burning the oil thru a cylinder(s). If the oil level gets low enough, oil pressure will drop, and it will trigger the low oil pressure code to come on. At that point, if you keep driving it, damage or death is sure to follow. You need to get this checked and resolved quickly. A mechanical oil pressure gauge screwed in at the oil pressure sending unit hole will tell you the actual oil pressure, but it sounds like loosing the oil is the main problem that needs to be addressed.

Good luck.

Dave

Did u replace pcv valve yet?

Which motor?

Didn't change the PCV valve.. The motor is a 5.0 Had a new alternator installed last week.

Not sure about this exact engine, but most modern engines no longer have a replaceable PCV valve.

Bob!!! It’s a Ford what did you expect.
Doug lol

Not real familiar with the F150's, but I know from a couple friends who own them, they don't seem to get the miles on them without a lot of issues, like the 3/4 and 1 tons. I will say that the Napa rebuilt lifetime warranty alternators are usually pretty good, I think every rig but my newest truck is sporting one right now. Never had to replace one at less than 150,000 miles after I installed it. . .UNLESS there was an electrical issue with the rig that was frying the alternator.
If it isn't leaking oil but it is going through it, it pretty much has to be burning it. This could be a bad sign, on the other hand a lot of American made vehicles burn oil from the time they are new and get plenty of miles without issues, just make sure and check it regularly and don't run it too low. Otherwise you need to find out if the low oil pressure light is an electrical issue or an oil pressure issue, if it is just a malfunctioning electrical sensor, no big deal, if it is actually low pressure, get it fixed before it causes you to buy a new motor.

Instrument cluster/dash might have problems. My 250 the fuel gauge quit working, then a year later mileage and speedometer quit. These new vehicles all kinds of things go thru or are controlled by instrument cluster. They are not cheap, make sure that's the problem before spending any cash. Got my replacement from circuitboard medics in sc?