stones

One of my exhaust manifolds has been really loud for over a year now, just at startup. Sound becomes more quiet as the engine heats up.

No lights on dash, but I do have emissions here so I'd like to get it fixed early 2016.

Curious what the shop charges for this install. Or if it's worth it to do both at once.

zippinbye

Brace yourself! It's an integrated exhaust manifold with catalytic converter. So the part itself is a big ticket item. OEM close to $1000 each side as I recall (list). As of about two years ago, with a 04 there was good news; an aftermarket part was available for around half of OEM. Hopefully it's just a gasket issue. My replacement was due to a bad cat. I'm a shade tree mechanic, but I decided to pass on the work because it's pretty damn tight and I was not in the mood. I think the labor was under $300 an independents Toyota shop I trust. I shopped sources nationwide and scored the OEM (no aftermarket part for VVTi engines/05 and up) and got it for about $700. Around $1000 overall. Hopefully it's a weld failure. Then perhaps it your existing unit could be repaired. Better yet, just a gasket. If it's a rust through, then I'd guess the whole thing is junk. So the range would be a few dollars for DIY and the best case scenario, up to over $1000. Best of luck.

zippinbye

Sorry, I missed an obvious diagnostic tidbit. With some certainty, it would be a gasket failure and/or a compromised fastener (nut backed off or sheared stud). The fact that it quiets with warm up is highly suggestive that metal expansion of mating surfaces more or less plugs the leak. That would not happen with a hole or puncture in or manifold or exhaust pipe. BTW, it looks more like a header than a manifold. So you are looking at labor mostly. Early 90s Nissan Pathfinders and pickups with the 3.0 V6 were notorious for a stud failure on the exhaust manifold. I have never heard of it on any Toyota V6 or V8, but odds are it might occur rarely. Barring any trickery with removing a broken stud, you might luck out with just 3 or 4 hours labor.