oil pressure gauge keeps droping out

[LMHmedchem]

Starting yesterday, my "check, gauge" light started coming on briefly. Today I noticed that when I came to a stop, the oil pressure gauge reading would drop to 0 and the light would come on. When I started going again, the reading would come back up to normal and the warning light would go off. The oil was low, so I added more oil, but now it is even worse with the reading staying at 0 for longer periods of time. Other than that, everything else seems normal. The engine is not running hot, there are no unusual noises or changes in performance.

Is this likely an instrumentation issue or a problem with the oil pump? The way it goes on and off, its seems to be acting like a flaky sensor, but the system is a bit too important to ignore and hope for the best. There defiantly is enough oil in the system, so it there anything else I can check to make sure that the oil pump is actually still working?

Help would be greatly appreciated, I am going on the road tomorrow and this is not a good time for engine trouble.

LMHmedchem

 

[FordFool2]

The oil pressure gauge is kind of a misnomer. Ford has been using a pressure switch to signal the gauge through a resistor to make it read 1/2 scale normal. The pressure switch is set around 5-8 psig so when it opens oil pressure is pretty low. A good engine should have 25-40 psig. You need to take this seriously. At idle, low rpms create a lower oil pressure output from the oil pump.

First thing, change out the oil sender/switch. See if that takes care of the problem. I have personnally seen them go bad.

 

[LMHmedchem]

Well I took it to my mechanic and he replaced the oil supply tube, but the boot on one of the front axles was also ruptured. He said, "this doesn't look good" while pulling at the boot, and then oil pored out of the boot and all over him. He was not amused. I don't know if this was just a sensor, but even if it was, I don't feel comfortable driving around without a working oil pressure gauge.

LMHmedchem

 

[Explorer Pete]

LMH, did the oil supply line cure the problem with the oil guage? The oil that came out of the rubber boot is for the CV joint that is inside the boot. You need to replace the boot and refill with the right amount of oil that is recomented. He should fave known about the CV boot having at least some oil in it. my 2 cents Pete

 

[LMHmedchem]

LMH, did the oil supply line cure the problem with the oil guage? The oil that came out of the rubber boot is for the CV joint that is inside the boot. You need to replace the boot and refill with the right amount of oil that is recomented. He should fave known about the CV boot having at least some oil in it. my 2 cents Pete

No, the gauge was kind of flaky for a bit more, and now it seems as if it has finally died. It always reads flat with the check light on. My mechanic thinks the issue is between the sensor and the ****pit, but we haven't had time to look into that yet.

I went away over the weekend and drive almost 4 hours each way. I am still not hearing any sounds from the engine, it ran cool, and the fuel economy was good. That would all lead me to believe that the oil pressure is fine. My mechanic also thought that was the case. On the other hand, the engine was running rough at idle and stalled out a couple of times when I was sitting at a light. Just as I was getting home, the "service engine soon" light came on, so I'm not sure what to do next.

LMHmedchem

 

[jayton]

Any updates on what happened next?
Did you try changing out the oil pressure switch?

Try one of these:
http://www.harborfreight.com/engine-oil-pressure-test-kit-98949.html

Drain the oil and look for glitter.

 

[LMHmedchem]

I have pretty well come to the conclusion that the gauge has died or there is an electrical/wiring problem between the sensor and ****pit. The oil pressure seems fine and changing the feeder tube didn't do anything. The pressure gauge has been flat for weeks now. I'm sure that the truck would have blown up long ago if the oil pump was dead or something like that. I changed the oil and listened to the filter filling up. It seemed to take the same amount of time it always has (2 seconds or so).

On the other hand, my check engine light has come on and it is running rough at idle, staling at a stop light every once and a while, etc. I had my mechanic take a quick look and the codes indicate that it is running lean on some of the cylinders. I could be the intake manifold gasket, but I'm not sure.

Any suggestions on that?

I guess I will have to get around to changing out the dead gauge, but I don't relish the thought of removing the dash to get at it.

LMHmedchem

 

[esclamada]

what's the code? its probably a leak in your vacuum hoses. Did your mechanic used an oil pressure gauge to verify that your oil pressure is OK? This will rule out the gauge not working properly (either a broken wire or gauge).




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[LMHmedchem]

what's the code? its probably a leak in your vacuum hoses. Did your mechanic used an oil pressure gauge to verify that your oil pressure is OK? This will rule out the gauge not working properly (either a broken wire or gauge).

I didn't write down the codes since he just checked quickly while I was getting gas. Some kind of vacuum leak seems likely. I have read that the v8 engines have less trouble with the intake manifold gaskets than the v6, so I hope it is the hoses. At least I think the hoses will be less trouble to repair.

I don't know if the pressure has been tested or not.

LMHmedchem