Within the last few months my 97 Neon developed an absolutely ear-piercing squeal when I turn on the heater, A/C, or rear window defroster. It sounds like a belt that gets progressively louder if I am driving under a certain RPM. If I were to throw my car into neutral and gun the engine it would go away almost immediately. It will return the moment I get under a certain RPM (I am mostly okay driving on the freeway if I can actually go 60, which lately is never).

It has made driving my Neon a nightmare now that it is winter. Between frosty windows I can't defrost and foggy windows that I can't get to dry from air circulation, I am driving a 4 wheeled coffin unless I want to deafen everyone within several hundred feet of me.

My Chiltons manual (it might not be Chiltons, I don't have it in front of me) says nothing about this. So while I may be able to use it to FIND the parts I need to address, I was hoping one of you could clue me into what I am looking for and what I might be needing to do.

 

most likely the A/C,PS belt...might be loose...just go under the hood and then right on the left side front is your power steering pump and the belt goes around it... just twist it a little and see how far it will go or get a finger under it or above it and either push down or up and see how loose it it. when (just a few days ago) our alt. belt went on our red Neon and that thing would squeal like no other..now its quiet

 

its the belt...i have to same problem...and i haven't fix it yet...but the noise...yes it's annoying

 

it could be ur pump mine was doing the same thing and the pump was trying to lock up

 

Okay, so I went under the hood and lifted the pump to tighten the belt as best I could.

I can't say that there was much of a change, but then I can't say there wasn't. The squeal is still there though. What gets me most is that it happens when I turn on the rear window defroster...

Here are a few details:

There is absolutely NO squeal if those three things are not on. Not so much as a hint from the belts.
My AC was basically going out all summer. It took forever to generate any cold, and that cold was rather mild and soggy feeling.
If I turn on the heater OR the AC, you can hear what I presume to be the A/C unit gasping and such

When an AC unit goes out and needs a charge, will it make noise? (Maybe it is has a crack/leak that whistles when it is on???) I can accept that the heater must somehow be involved in the AC unit (accept, but not explain, it makes no sense to me), but again... The rear defroster!?!?!

I honestly can't place the squeal to the belt location. I am willing to try working the belt again (I'd say it has about a quarter in of play at most, and that is probably over-estimating. It is pretty damn tight).

 

try replacing your 2 belts on the engine. sometimes tightening them isnt enough. same case with my power steering pump and a/c unit as well. another possibility, its not likely but it could maybe be the alternator itself. as far as the a/c goes try to getting your a/c system recharged and if you need it recharged that usually means theres a leak. if you know a/c check that out if not take it to any auto service shop