When drive on the road, the oil pressure light was ON. Stop the car at the gas station to check the oil, the oil is ok.

Then start car, the check engine light on also (Code read out P3040). Car is running rough now.

Need help.

Thanks.

The oil pressure light on is potentially VERY SERIOUS...severe engine damage occurs if it is not properly lubricated. Could be failed oil pump, clogged oil filter, clogged oil pickup screen, double gasketed oil filter and low oil.

Faulty pressure sending unit is not damaging but dang scary with OP lit up.

Running this engine is very risky until you determine the cause. A mechanic can verify the pressure bypassing your gauge.

Code P3040? Don't know it...maybe code P0304? Cyl 4 misfire

Thanks for replay.

I will change the oil filter fist. If the problem is not fix. Then i will change the oil pump. How difficult to change the oil pump?

The code is P0340.

Thanks again for your help.

The Ford manual says that a code P0340 is Camshaft Position (CMP) Sensor Circuit Malfundtion. The test fails when the PCM can no longer detect the signal from the CMP sensor. Possible causes is a laundry list of possibles, presumably with the most likely listed first: CMP circuit open, CMP circuit short to ground, CMP sircuit short to power, SIG RTN open (VR sensor), CMP ground open(Hall effect sensor), CMP misinstalled (Hall effect sensor), Damaged CMP sensor shielding, Damaged CMP sensor, Damaged PCM.

I suggest that you do a search on this forum for P0340 and read those. This circuit is sensitive to interference from other circuits that a faulty coil pack or other faults could cause. To quote Ford, "Harness routing, harness alterations, imporper shielding, or electrical interference from other imporperly functioning systems may have intermittent impact on the CMP signal".

I'd also do a search for "oil pressure" and read those. Chances are that someone else has already dealt with your same problem.

Good luck.

Jim

The oil pressure sensor is located on the front (passenger side) of the engine (radiator side) UNDER the power steering pump / alternator bracket. You have to remove that bracket to see it. It is in between the "timing cover" and the A/C compressor.

It is shown in my picture titled "A look under Power Steering Pump / Alternator Bracket" in my pictures at
http://community.webshots.com/album/201931518cScpNK

I have not replaced the oil pump.....you can find instructions at www.autozone.com under vehicle repair guides. Make sure to look at the instructions for the correct engine, as they list BOTH 3.0L and 3.8L engines.