2002 Mercury Mountaineer Car makes a humming noise?

  • V8
  • 2WD
  • 91,000 MILES
When I am driving down the road I hear my car making some sort of humming noise. When I let go of the accelerator is when I really hear it. I thought it was my tires but I am sure its not that. What could the possibilities be for the cause of that noise?

Also I received a p0305 code when I saw my mechanic scan with the computer, it said camshaft sensor, that already been replaced by dealer they have no idea what it is. Any opinions on that one? Thank you.
Do you
have the same problem?
Wednesday, October 14th, 2009 AT 3:18 PM

1 Reply

On the differential humming noise.
Have you checked the differential's fluid level?
All you need to do is ratchet out the fill plug and poke your finger in, the fluid should be close to the fill plug hole.

Have you changed your differential fluid somewhere in the 91000 miles?
I you have not.I would change the differential fluid
and hope that solves the problem.
It could be a bearing.
I have heard a little twist in the drive shaft pops up now and then.

I have not seen much about a camshaft sensor related to code P0305. That usually is related to Cylinder 5 Misfire.

Check Engine Light Code P0305.
Misfire Detection Monitor - Cylinder 5 Misfire

A misfire is nothing more than a lack of combustion, which can be caused by poor fuel quality or metering, low compression, lack of spark or un-metered air entering the engine. There are other possible, less obvious causes as well, such as un-commanded Exhaust Gas Recirculation (EGR), flow. When the misfire monitor detects a misfire, it will trigger the check engine light with the specific cylinder number as the last digit in the P030X code. For instance cylinder 1 misfire is P0301, cylinder 2 is P0302 etc. In this case you are left with a P0305 in the computer memory.


* Check Engine Light Flashing
* Rough running, hesitation and/or jerking when accelerating.
* In some unusual cases there are no adverse conditions noticed by the driver.
* In some cases there may be performance problems, such as dying at stop signs or rough idling, hesitation, misfires or lack of power, especially during acceleration and a decrease in fuel economy.

If you have a "Advance Auto" nearby they will run the code scan "free of charge" for you and tell you exactly what the problem is.
Good Luck, I hope things work out for the best;
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Sunday, November 15th, 2009 AT 7:18 PM

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