Loud Screeching when accelerating and when AC is on

jezejeze Member Posts: 15
edited March 2014 in Mazda
Hey, Here this is a call for HELP. Today while driving I noticed my battery light came on. Then a second later I noticed a very loud screeching sound coming from my car. I turned the A/C off to hear it better and I could only hear it when I accelerated but noticed the battery light went off when I did that. So I decided to turn the AC on again. the battery light came back on and the screeching got infinitely louder. So I parked the car and revved the engine stopped, then turned the AC on. Both times the screeching was louder. So I popped the hood w/ the AC on and noticed the sound came from the vicinity of the timing belt. Does anyone have any ideas. I already towed it to the dealership but just want to lessen the shock and have idea of what it could be. I'm thinking either the timing belt(had replaced 2 months ago) or the alternator since the battery light came on. Any help would be appreciated. Thanks in ADVANCE.


  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    You have one or more loosedrive belts. If the belts are old, or have a shiny glaze on them, replace them rather than just have them tightened. As belts get old they stretch and this is what is happening.
  • jezejeze Member Posts: 15
    Hey nice tag!! Thanks for replying. I am almost sure that I had the drive belts repalced w/ the timing belt or at least that is what the mechanic told me. Could you please explain to me the link between the AC, the acceleration and the battery light. I like to take every oppurtunity to learn as much as possible.

    Thanks Again.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    I'm sure you understand that the engine belts are held "tightly" against various pulleys. One of those pulleys is attached to the rotating mass of the engine. That is, the engine makes the pulley spin when the engine runs. The spin of the pulley "pulls" on the belt that is wrapped a little bit around it. The belt moves. All the other pulleys in the path of the belt are then subject to being rotated by the belt moving across part of the edges of the pulleys. These pulleys are attached at the center to devices that resist being moved by the pulleys. If the belt grabs the pulley surface tight enough, the device gets the energy transfer via the rotation. If the belt is not very tight, sometimes certain devices (like air conditioner compressors) will put up enough resistance to movement that the belt slips on the surface of the pulley. This phenomenon is often accompanied by a loud screeching noise.
    Whew! I'm tired, are you? (:oÞ
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Or a less exemplary explanation -- when the belts slips, the alternator doesn't ALT anymore, so the red light goes on.

    You might encounter a similar situation when you drive through a deep puddle, and water soaks the pulleys, therefore imitating a loose belt problem.
  • jezejeze Member Posts: 15
    thanks for the help. Found out from the dealer that it is the tensioner. They want 550 to repair it. Is that expensive?
  • swschradswschrad Member Posts: 2,171
    saw your posts a few items down, the design of your engine makes that an impossible job, and the part is obscenely priced as well, is the summary.

    sorry to advise, welcome to the pioneering world of New Technology. there's a reason they call 'em pioneers, you can recognize 'em by the arrows in their backs.

    I would really like to see the top 20 maintenance procedures detailed in photo and text on billboards in the dealers' showrooms, because this is getting to be more rule than exception in the gouging of america, and buyers should be informed whether the car they are looking at is serviceable.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Geez, I just spit coffee through my nose! $550? What's the big deal here?
  • jezejeze Member Posts: 15
    I don't understand if you are saying it is expensive or not to bad.

    The breakdown is 300 for the part and 250 for the labor (around 4 hours).

    You are so right. changing the timing belt was 700 and now this is another 500 and the spark plugs were 300. My brother and I own the same car. He is getting rid of his (80,000) miles and getting a BMW in 2 months and I will be getting rid of mine in about 3 years when my g/f(dating 5 years) gets out of law school. Hopefully I can make it. Obviously for him and I these are our last Mazdas.

    What pisses me off so much is the difference in parts prices i am seeing. I priced the parts today. Seems no used lots have it. But I can get it for 180(another dealer). Take it over to Peb Boys who ownly want 75 to change it(don't know why) and it would cost me around 330(inc. 80 diagnostic fee). I'm debating if it's worth 200 to have Pep Boys butcher it? Or would they?

    What do you guys think. Thanks, It feels good talking about it. Only joking....
  • swschradswschrad Member Posts: 2,171
    I can see the parts difference... double-platinum plugs for my V8 exploder are $11 each list, but the parts guy at the dealership cut that 50% because of allowances they get from Motorcraft. it could be one dealer is out for blood, and the other isn't.

    how Pep Boys figures to get that in in an hour of labor, when to tighten the oil filler cap your dealer says the engine needs to be hoisted, is another question entirely. maybe they have a "cheater bar" and the dealers are not allowed to ;) it could be they're saying, hey, how hard can it be, without looking at the Mitchell estimate.

    on my car, looks like it would be easiest to pull the alternator, then pull the multi-device mount bracket and the tensioner after they get clearance, and then replace the tensioner on-bench... but I haven't tried it. don't want to.
  • jezejeze Member Posts: 15
    Hey, Thanks so far. I hope you know I was only joking about the oil change. It isn't that bad but everything else is. Basically to do anything to the engine you have to remove half the engine.

    Hey BIG Question! I just found one for 75 shipped. My question is how often do these things break? Would I be better off getting the new one? Thanks.
  • fleetwoodsimcafleetwoodsimca Member Posts: 1,518
    Most of us have never needed to replace one, ever. If you find out this is not a typical Mazda problem, then the used one might be fine. If they break a lot on Mazdas, the choice will be tougher.
  • jlflemmonsjlflemmons Member Posts: 2,242
    4.3L, the tensioner started howling. Dealer wanted something like 50-75 for it. Pulled it off, pressed out the bearing using a socket and a vise, bought bearing at local bearing supplier for ~$10, pressed in back in the same way it came out and was back on the road in about 2 hours total.

    That's how MECHANICS used to do it before they became technicians.
  • swschradswschrad Member Posts: 2,171
    it's harder if the bearing presses into a well instead of an open hole in an arm, but an electric frypan and some electronic freeze-spray (or a crackling cold ice cube or two) to sit on the bearing itself can work wonders to get clearance to remove the old one easier
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