Car repair - Engine screeches on start

My wife took my car in and got an oil change and a new alternator belt, I believe.

Now, the car engine schreeches when I start it.

I turn the engine on. I put it in drive. It starts schreeching. It starts as a sort of light higher pitch (almost chirping), then quickly becomes louder with a lower pitch, then back up to a higher pitch, then does a quick fade-out. It kinda sounds like Godzilla.

The schreeching lasts maybe 5-10 seconds, and I have only noticed it on a cold start (cold engine, not cold weather). I have not heard the sound at any other time.


Sounds like the belt to me. Perhaps the new one needs to break in? I dunno, don’t have a lot to work with.

Sounds like the belt is slipping. Try tightening it.

(EDIT: Looking at posting times, I feel like Milorad Cavic. :stuck_out_tongue: )

I have not checked under the hood for Godzilla.

If Roy Buchanan weren’t dead I’d suggest maybe he was Sneaking Godzilla Through The Alley just as you were starting the engine. :smiley:

I had my alternator changed in the Jeep last year, so of course I got a new belt. When I used the air conditioner it squealed. The mechanic tightened it, and it stopped.

If they just replaced the alternator they should have replaced the belt. In any case, it sounds like the belt is loose.
Make and model of car please…

Cause it makes a huge difference if it’s a serpentine belt or if the alternator is driven by it’s own belt. Older cars had the alternator mounted to adjustable brackets so you could take the slack out of the belt and prevent screeching. Newer cars mostly have the serp belts. You can’t really adjust those, they have tensioners that do that.
You could have an old serp belt slipping, a bad tensioner, a poorly fitted alternator, etc.
Make and model…

2002 Mazda Protege

Get the charging system checked. Starting the engine takes a lot of power from the battery, to recharge, the alternator needs to put out a lot of “juice”, this takes a large amount of energy transmited from engine to alternator via belt. The belt could be tight enough for normal driving, just loose enough for when a major load is applied it slips. Check the charing system.

Take it back to the garage and have them do their job properly this time.

New belts often stretch significantly during the first 50 miles or so as they break in. On your car’s design, the alternator belt is adjustable, and almost certainly a re-adjustment will stop the noise.

Occasionally a new belt will be noisy even when properly adjusted. This indicates a faulty belt (yes, even though it’s new) which needs to be replaced.