What in the whir is that noise?

by "mkbruin, Atlas VP" (mkbruin)
Published 08/02/2017 at 10:49

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This is the 1992 Celica I bought from Chariot. I noticed a....strange... noise as the revs fall. It only occurs as the revs drop, and only near idle. It’s that short rattle/whirring sound. Noise comes from the accessory side of the engine. Any thoughts?

As for how it runs, it idles fine and revs freely, as you can hear in the video. Under load, there is severe hesitation and stumbling, with NO CEL I’m not convinced it’s a timing issue, as Chariot was told. I’m thinking one of a handful of things:

1) distributor seal leaking, allowing oil in the dust

2) O2 sensor

3) coolant temp sensor

4) clogged cat

5) jumped timing (off by one tooth?)

Projects are fun! My pastors son is going to love the Celica when I get it sorted.

Replies (6)

"RamblinRover Luxury-Yacht" (ramblininexile)
08/02/2017 at 11:02, STARS: 0

Can’t see an AC compressor in the clip - does it have one? Hopefully not something like a compressor clutch but you never know. I had repeat issues with rattling on decel with my old VW, and it was brackets working loose, so that or an idler might be worth checking for. Maybe motor mount?

"Wagonlife740" (wagonlife740)
08/02/2017 at 11:10, STARS: 0

For like 15 bucks you can buy one of those stethoscopes from just about any auto parts store. These are tremendous help when locating sounds.

"punkgoose17" (punkgoose17)
08/02/2017 at 11:13, STARS: 0

I was thinking on similar lines as RamblingRover some kind of pulley or tensioner arm is worn or wearing out and is binding or defelecting when the speed decreases.

"crowmolly" (crowmolly)
08/02/2017 at 11:24, STARS: 1

Under load, there is severe hesitation and stumbling, with NO CEL

Baseline it.

Do the plugs, filters, etc check out? If the plugs aren’t recent I’d throw new plugs and wires at it. Only a few bucks.

Start with the easy and cheap stuff first.

"boredalways" (boredalway666)
08/02/2017 at 11:28, STARS: 0

Bad bearings in the turbo? But in all seriousness, I was thinking it was the alternator. It appears that others have offered more knowledgeable advice.

"merged-5876237249235911857-hrw8uc" (merged-5876237249235911857-hrw8uc)
08/02/2017 at 11:41, STARS: 0

Does the alternator have a clutch pulley on it? Sometimes as those go, you’ll get some nasty noises.