Deafening scream when started

[Honestmechanics?]

Hello. My 95 Rodeo (6 cyl) has an ear percing scream/squelch sound when started. Imagine an eagle screaming into a microphone with the volume turned up. This seems to happen every winter. It last for about 20 seconds, stops then will start again at long stop lights. 3 out of 4 Isuzus/Passport at work make the same noise. People actually cover their ears. We've had belts replaced, now that same shop says we need a timing belt job. The other shop says that's not true. I'm supposed to call the dealer today, but I wanna ask you all 1st.

[eric147]

Check for a cat under the hood.

But seriously, folks- I run into the same thing with my 97 Rodeo. It's the alternator belt. Every winter I have to tighten it down. Sometimes a couple of times during the cold weather. Never a problem in the warm months.

It takes a 10mm socket to loosen the adjuster (from underneath), and a 12mm socket to tighten the belt.

I could probably do it in my sleep by now.

[surferfletch]

That belt needs tightening about once a month I think! Mine is squeeling now. I'll get it soon!

[Honestmechanics?]

Thank you so much for the help, I'm gonna try your tip today. People kept saying put soap on your belt or get some belt dressing or its your AC belt or you need a $500 timing belt job. Did the soap and the dressing (even WD-40), nothing worked. I was going to take it to Isuzu today, but now I'll try this 1st.

[Honestmechanics?]

Would you be able to tell me what to look for? I need instructions as I have never done this b4, I believe I located the alternator. Is it the one where you can see a coil inside on the top part? I counted 3 belts, my husband went under the truck, I told him which 1 was the alernator, he could not find the bolt underneath. Is there a picture online or instructions?

[stanger42]

i have this same problem with my '94 rodeo. i just replaced the alternator and there's no play in the belt. could anything else cause this god awful noise? the car sat for about 5-6 months in an alaskan winter so...oil is fine, could stand to be changed but no water or anything, appropriate level...but it only makes the noise for approx 20-30 seconds but no more.

[Honestmechanics?]

I filed a complaint w/ the NHTSA - National Highway Traffic Safety Administration (on my VW's leaking recalled/but no replacement gas tank too). I read on this board that an Isuzu Amigo owner complained and received a call from Isuzu. These complaints lead to recalls. I called and spoke to a rep, then placed another complaint on the website. My Husband met a 1998 Rodeo owner at work that has the problem too. Brings my personal Isuzu scream count to 4, not counting this site.

[Cat Fuzz]

I'm sure its just your alternator belt. No need to file a complaint. It's either loose or worn. I had the same problem until I tightened it.