A flex pipe is a kind of metal bellows. It’s a flexible piece of pipe that creates some flexibility within the exhaust system. It basically acts as an exhaust pipe connector. They are typically made out of forged or stainless steel. Forged steel 150# flanges are rated for pressures up to 285 psi at 100 degrees Fahrenheit, according to ASME B-16.5 flange specifications. The allowable pressure is reduced to 65 psi at 850 degrees.
Flex pipes are an essential piece of equipment for any front wheel drive vehicle and on most all-wheel-drive vehicles. For front wheel drive cars, the motor is mounted transversely. So when you accelerate, the motor rocks and the flex pipe protects your exhaust system from breaking. Without that extra flexibility, the rocking motion would crack your exhaust system. That’s what causes the loud leak when your exhaust bellows malfunction.
What are the signs of a flex pipe exhaust leak?
It’s not always easy to notice a flex pipe exhaust leak or even when it starts to break down in the first place. Here are some tell-tale signs that your exhaust flex pipe is leaking.
- Loud noises: One of the first signs of an exhaust leak is a loud noise. If there’s a crack in your flex pipe, it will cause an excessively noisy engine. Your pipe might be producing a hissing or tapping sound that can get louder when you accelerate.
- Bad smells: If you smell gas when you’re driving your car, you probably have an exhaust leak. Dangerous fumes can find their way into the cabin of your vehicle when you have a flex pipe exhaust leak, giving off the smell of raw gasoline.
- Decreased power and efficiency: Engine performance issues, like decreased power during acceleration or fuel efficiency, are another important indicator. If you notice either of these issues, you have a potential leak in your exhaust system. This is due to a loss of backpressure from the leak.
- Hanging exhaust pipe: Obviously, if your exhaust pipe is hanging, you have an exhaust problem. There might have been a crack (causing a leak) that got larger, causing part of your pipe to drag or hang from the vehicle.
If you notice any of these signs, you may have a flex pipe exhaust leak. It’s extremely important to replace your flex pipe because a broken one can cause serious damage to your exhaust system.