#MANIFOLD EXHAUST CRACKED#
So why bother fixing a cracked exhaust manifold if it doesn’t ruin performance or reliability? Once you’ve driven in a parking garage, tunnel, or beside a wall, you’ll understand. For that reason, your vehicle could potentially fail a safety inspection if you’re buying or selling it. As long as the Check Engine Light isn’t on and the person running the test doesn’t notice a leak that’s too big to ignore, you should be good to go.Īs with any form of exhaust leak, carbon monoxide poisoning is a concern. Driveability won’t change either.Ī cracked exhaust manifold shouldn’t cause your vehicle to fail an emissions test. The amount of exhaust gas escaping isn’t big enough for the ECU to notice.
Unless you’re dealing with an extreme leak, a cracked exhaust manifold won’t cause a Check Engine Light. The ticking sound might annoy you enough to make you want to walk home, but it won’t force you to. It will never leave you stranded on the side of the road. Most cracked exhaust manifolds won’t affect the function of your vehicle. Potential Damage from cracked exhaust manifolds You may notice a sulfur smell with a manifold that’s cracked this badly.
#MANIFOLD EXHAUST CRACK#
If your ticking sound remains even when the engine is warmed up (mine did), that means you have a larger crack that still leaks when the metal has expanded. When it warms up, the crack gradually closes with the heat expansion. When the engine is cold, the crack is large enough to leak. The reason the sound goes away when the engine is warm is because metal tends to expand with heat. It will get louder when more load is on the engine, and in many cases it’ll go away once it warms up.
This ticking sound will speed up and slow down with the revs of the engine. The most common sign of a cracked exhaust manifold is a loud ticking sound coming from the engine bay. Want to read more about my Toyota 4runner? All the details are shared in this feature article: Symptoms of a Cracked Exhaust Manifold Typically, the cracks will appear where the edge of the tube is welded to the flange. The combination of the thin metal and the excessive weight of the catalytic converter hanging off the end is what causes them to crack. Other automakers took a similar approach to this, and surprise surprise, they suffer from the same problem! This required mating the catalytic converter and exhaust manifold into a one piece design. In order to produce the desired readings, they needed to place the primary catalytic converters as close to the head as possible so that they’ll heat up and start working sooner. The 4.7’s manifolds are a tubular design made of thin steel. The reason Toyota used this flawed design is to lower the emission readings during cold starts. This issue exists thanks to emission regulations. If it were up to them, I’m sure they would have over-engineered them just like every other part of the 4runner. Toyota isn’t the only one to blame for your exhaust manifolds cracking. Unfortunately, it’s not a matter of “if” but rather “when” the exhaust manifolds will crack. It’s powerful, reliable, easy on oil and incredibly well balanced. Toyota used it across their entire lineup of trucks. Read on to find out why I believe upgrading to Doug Thorley headers is the best way to fix them. At some point, you will wind up with cracked exhaust manifolds on your V8 4runner, Land Cruiser, Tundra, Sequoia or Lexus GX470. There’s one issue holding Toyota’s 4.7L V8 (otherwise known as the 2UZ-FE) back from being the perfect engine.