Cause of growling noise when accelerating?

[xorrbit]

I have a 2007 1NZFE ATM 5D Yaris with 125,000ish km on it. Awhile back I noticed it started "growling" whenever I was accelerating. This only happens while in gear (does not happen when in neutral and revving) and only when you accelerate. It is not noticeable when you're coasting or cruising at speed.

From searching the forums it sounds like maybe I should check an exhaust manifold gasket (either tighten the bolts or replace the gasket altogether) or just check the exhaust for a hole/leak. Does anyone know which gasket is the one that normally goes? I'm thinking #11 in this diagram: http://www.toyotaonlineparts.com/auto-parts/2007/toyota/yaris/base-trim/1-5l-l4-gas-engine/exhaust-system-cat/exhaust-manifold-scat

I'm also wondering if anyone has any other suggestions or knows what it might be - I'm going to be doing an oil change this weekend and plan to spend some extra time trying to figure out why it is doing this. Note it has been doing this for quite awhile (> 6 months) and doesn't appear to be problematic per se, just annoying :).

Thanks!

[Ben_]

I would narrow it down to exhaust engine or transmission. If it is exhaust there are methods to find exhaust leaks online

[canadian deacon]

It's been my experience that the flange which connects the exhaust to the manifold deteriorates over time. I have had a new flange put on at a local muffler shop for 75 bones rather than replace the exhaust.

There may be some issues trying to do this yourself because of difficulty getting access to the flange from below. It's possible if you have access to a lift but hard if, like me, you do not.

I live in Eastern Canada so the salt used in the winter makes it difficult to remove the flange nuts for replacement.

[John Lenin]

The Exhaust Flange Gasket is a common problem with the Yaris/Echo models ... they deteriorate over time and invariably leak ... had one done in an Echo I once owned and now have to have the same done with my current '09 Yaris ... gasket + spring bolt kit from wrenchmonkey.ca = $34.00 delivered.

[shepd]

If you don't have a lift, you will just need a standard ratchet set and a set of long extensions. Princess Auto has some decent long extensions. It is not a hard job (well, harder than changing oil, but easier than a brake job), but you will want to jack the car up as high as you reasonably can on all four corners so you fit underneath it. I did mine outdoors on the driveway. Just be very careful to check the car is stable when the entire car is jacked up like this and don't get crazy banging on stuff, you don't want the car to slip!

With the extension you can get access. It should take 30 minutes or so unless the gasket is really stuck. You may want a breaker bar to get things moving the at first. :) To be honest, it's mostly frustrating because you can get your hands on the bolts and you figure that would mean you can get a wrench in there, but they just barely overlap the crossmember so no dice.

As far as that diagram goes, the gasket we're talking about here is #6.

LOL here's a new thread on it again:

http://www.yarisworld.com/forums/showthread.php?t=52136

Buy the bolt/spring kit with the gasket (#7 and #8 on your diagram x 2). You'll be happy you did. Exhaust parts turn to dust in no time.