2000 Windstar - Screeching Noise

Our 2000 Windstar makes an intermittent, neighbour-waking screeching sound. It appears to come from the transmission side of the engine. May happen 2-3 times a week - the sound only happens in Park or Neutral - put it in gear and it quits.

Now the silly parts - the audio system will occassionally cut out - the radio buttons work normally, changes stations, etc - but no sound for several seconds/minutes. When this happens, the screeching sound often happens the next time the vehicle is parked.

Also, I was trying to find the source of the screeching noise on the weekend - I parked the vehicle and got out - no noise - shut the driver door and the screeching started. This happened twice and I haven't been able to duplicate it since.

Any ideas or do I call an exorcist?

Sounds like a grounding problem in the audio system to me. Do you have an original factory radio or an aftermarket?

Do you have an aftermarket security system installed? Is it a mechanical (belt/bearing/metal to metal) screech, or an electronic type noise (horn/speaker/siren).
G/luck
Joel

It sounds like a mechanical noise...like a dry bearing.

We have the factory AM/FM/Cassette/CD in-dash player.

Update - the loise was happening this morning when I stopped at a PartsSource store... the store person listened and suggested it might have to do with the clutch plates since only in neutral or park.
He suggested I check all electrical connections on the transmission for corrosion and possibly Lucas transmission additive.
I looked at 2 wiring blocks: - white connector on the top of the trans, and a black one that attaches where the shift linkage goes into the tranny. The white one looked like it had some moisture in it...I dried it out with a swab. Does this make any more sense?

Before reading your last post, I was already guessing something electrical... leading to sudden heavy loads on the alternator ... and serpertine belt slippage....or alternator bearing noise. The idler and take-up pulleys may also give noise when the belt sees high stresses. Therefore you may have a "cause and effect" situation where there are two contributors.

If you haven't already corrected your problem, the next time you get the screeching try unplugging the alternator to see if there if the noise is eliminated.

Do you mean pull out the wiring block on the alternator (has 3 wires in the block)? Can I do this with the engine running without damaging anything?

Update....this could be the starter solenoid kicking in....makes sense: only happens in park or neutral, other electrical (radio) shutdown during starting. While it was making noise today I hit the fuse box and the noise quit...is there a relay in the fusebox that would control the starter?

Yikes! the starter engaging on an already spinning flywheel! That could get ugly :banghead: . Could this be a bad starter/solenoid? Not sure how this ties in with the radio though!? Unless maybe the voltage drop of the starter running causes the radio to drop out :uhoh: .
G/luck
Joel

There is a "starter interrupt relay" that you should be able to pull that will (normally) stop the starter from being engaged.
Check your glovebox manual. I believe it's in the box near the battery. One of the larger relays.