SEFI buzzing noise

[mfmagicmike]

Hi everbody,

I own a 1989 Ford LTD Crown Vic 5.0 SEFI since last year. Ever since I bought the car, it made a buzzing noise at idle that seems to come from the rear end of the engine. When I drive, the noise apparently disappears, but is audible again as soon as the car stops.
It never really worried me, the engine working perfectly, never stalling or else.
Yesterday, a friend of mine heard it and decided it (the noise) to be not normal. As this guy knows a lot about mechanics I tend to believe him.

What do You think? Could it be a faulty fuel pump ?

Thank for You advice,

magicmike

[gadget73]

Thats probably the AOD noise. They sometimes make a buzzing noise or a whine like a low power steering pump. Its normal and ignorable. Its something with the pump pressure relief that makes that noise.

[mfmagicmike]

The noise is comparable to a steady turning ratchet. I also have a pressure relieving whistle when I turn the engine off. It must come from the steering pump or elsewhere and doen t worry me.

I read elsewhere that a front fuel pump could cause this kind of buzzing, a sign of in tank fuel pump failure (apparently some cars/trucks have 2 fuel pumps, which is not the case in the Ford LTD).

Thanks for Your advice.

[mfmagicmike]

Since You came up with the AOD transmission, maybe You could help me with a small problem I have:

I noticed that a small amount of transmission fluid is leaking on the rear end of the engine block. I recently changed the filter, oil and gasket, but the leaking goes on. I wonder if I am overfilling the transmission or if there is a seal or gasket somewhere between the transmission and engine that may cause the leak?

[gadget73]

there is no front fuel pump on the Vic, just the in-tank pump.


There is a front seal where the torque converter goes into the transmission that could be leaking. It would drip out of the bellhouse between the engine and trans if that was the case.

[86VickyLX]

Since You came up with the AOD transmission, maybe You could help me with a small problem I have:

I noticed that a small amount of transmission fluid is leaking on the rear end of the engine block. I recently changed the filter, oil and gasket, but the leaking goes on. I wonder if I am overfilling the transmission or if there is a seal or gasket somewhere between the transmission and engine that may cause the leak?

How about the tranny dipstick tube? Mine would leak until I cleaned it up and covered the base with rtv.

[gadget73]

theres an O ring for that to seal it properly

[CheeseSteakJim]

Unless you're 100% sure that's ATF leaking, it's probably motor oil. You won't find many 5.0's without oil on the back of the block. They all leak.

[85crownHPP]

does it go away when you put it in park or neutral? if so, ignor it.

[88grandmarq]

Hi everbody,

I own a 1989 Ford LTD Crown Vic 5.0 SEFI since last year. Ever since I bought the car, it made a buzzing noise at idle that seems to come from the rear end of the engine. When I drive, the noise apparently disappears, but is audible again as soon as the car stops.
It never really worried me, the engine working perfectly, never stalling or else.
Yesterday, a friend of mine heard it and decided it (the noise) to be not normal. As this guy knows a lot about mechanics I tend to believe him.

What do You think? Could it be a faulty fuel pump ?

Thank for You advice,

magicmike

It's the smog/air pump purging. my car used to make a similar noise. noise went away when the air pump siezed and it got bypassed with a short belt.

[88grandmarq]

The noise is comparable to a steady turning ratchet. I also have a pressure relieving whistle when I turn the engine off. It must come from the steering pump or elsewhere and doen t worry me.

I read elsewhere that a front fuel pump could cause this kind of buzzing, a sign of in tank fuel pump failure (apparently some cars/trucks have 2 fuel pumps, which is not the case in the Ford LTD).

Thanks for Your advice.

whistle noise is the butterfly on the throttle body closing. if you take the air snorkel off it the noise is louder. not really much you can about it, it doesnt effect anything.

[86GmLsCoupe]

It could be the fuel pump whine, and they get louder as they age. When you get bored or have to much time on your hands, stick your ear down by the driver rear tire with the car running. You should hear, what I like to call a hiss, or buzz noise, from inside the car its more of a whine. These fuel pumps make some noise, but have really good track records and seem to last a good while so I wouldn't worry about it. The stock pump is a Bosch/Motorcaft. Drivetrain noise seems more apparent to me at very low speeds, but again, I think thats just the way the car is.

[mfmagicmike]

I would go with a faulty air pump. The buzzing really comes from the back of the engine, probably from behind the intake manifold. IŽll take a look at it this WE and tell You about it.

As for the oil on the lower engine block, it is located just above the oil pan, it is pretty clean, could be engine oil (I changed it recently). I will check the dipstick tube and the AOD to see where the leak could come from.

Thanks for Your ideas!

[CheeseSteakJim]

Take some off with your finger. If it's a brownish color it should be oil. If your AOD is in good shape then the transmission fluid should be pink. However, if your AOD is starting to die then it might be a pink with a blackish tinge.

[mfmagicmike]

I changed the AOD oil and filter a few weeks ago. The old oil was dark pink and there was a light dark film in the pan when I cleaned it. Please tell me that this is normal wear and not a sign of a premortem AOD (I still need it!!!).