Odd exhaust issue

[Dubdoc]

I recently bought a 2009 Yaris sedan which was well optioned and well cared for. About 2 months later, it has developed an exhaust noise. The muffler shop says it's a cracked exhaust manifold. Is this a common problem. The shop says they've never seen it on a Toyota before. :confused:

[CTScott]

Cracked ones are very uncommon on our cars, as the OEM manifold is welded tubing, rather than being cast. My bet is that rather than a crack that it is the gasket between the manifold and the mid pipe. That soft metal gasket is a far more common failure point.

[Dubdoc]

Cool. I knew the Corolla was tubing but just assumed this one was cast since the tech mentioned "cracking".
Typical muffler shop incompetence.

[CoryM]

It's much less common with steel manifolds, but can still happen. I'm with CTScott though, probably a gasket. If it's a primary exhaust leak (the tubes coming from each port, before the collector) it will sound more like a * tack tack tack* noise. Especially when cold starting. If it's just a steady, louder noise, it's after the collector.
Cheers.

[BobTheYaris]

Would it sound like a sorta vacuum leak under load while driving. Ive had something similar but cant find the source [emoji21]


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[CoryM]

Would it sound like a sorta vacuum leak under load while driving. Ive had something similar but cant find the source [emoji21]


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I would guess you're just hearing the air going through the airbox or past the throttle body. There is a normal air noise in the Yaris under certain conditions.
Cheers

[shepd]

A broken exhaust manifold / header will make a ticking noise, and you may smell exhaust in the engine bay. Although you may get that (but louder) if the donut is broken.