A running automobile engine emits large amounts of toxic gases and hydrocarbons due to the process of combustion that occurs inside of its chambers.
An exhaust system is installed underneath the car which is used to remove and expel the gases. This system uses a series of tubes that lead to an exhaust pipe from which the harmful pollutants exit.
A flex pipe is only a small piece of piping in the exhaust system which, as its name suggests, is flexible enough to withstand the vibrations from the engine. If an exhaust system was entirely comprised of straight-piping and no flex pipes, it would become severely damaged in only a short amount of time.
But flex pipes can become damaged too, although not from the engine. It’s important to know the symptoms of a broken flex pipe, how to avoid problems from happening, and how much it costs to replace.
Exhaust Flex Pipe Retail Pricing
The price of a single piece of exhaust flex piping ranges from $9.51 – $116.86. There are various factors that will make the price range from high to low. A few of these factors include the shop which sells the part, the brand of the part, and the year, make and model of your vehicle.
Flex pipes may also be sold either as a small connecting piece or the entire length of flexible tubing. The inlet diameter size also makes a difference.
Here’s an example of how the car flex pipe replacement cost can drastically change depending on the aforementioned factors. A Different Trend-branded double braided exhaust flex pipe with an inlet diameter of 1.75” will cost $13.25, but a Different Trend interlock exhaust pipe with a 4” inlet diameter and an 8” body will cost $33.16.
Additionally, since different types of flex pipes are used for different vehicles, we’ve included a list of cars below and the corresponding overall cost to replace their flex pipes. Keep in mind that these numbers include the labor fee together with the price of the flex pipe itself.
|2005 Lamborghini Gallardo||$264|
|2003 Ford Escort||$261|
|2007 Mazda MX-5 Miata||$258|
|2007 Lexus GX470||$121|
|2003 Audi Allroad Quattro||$739|
|2011 Chevrolet Corvette||$840|
Where to Replace an Exhaust Flex Pipe?
Exhaust systems can be inspected and diagnosed by either local independent mechanics or auto technicians that work at brand dealerships. Be aware that the price of replacement will vary depending on which of these locations you bring your vehicle to. Dealerships tend to charge more for labor.
Both establishments have their pros and cons, however, so no matter which place you decide to patronize, what’s important is to do it as soon as symptoms of a problem become evident. A couple of different options that may have local shops in your area are BMW, Ford, Chevrolet, and Volkswagen.
If your vehicle has a different manufacturer, check in the yellow pages or online to find their nearest service center.
Independent repair garages such as Harlan Automotive and Metric Motors have shops in multiple states and shouldn’t be hard to find if you’d like to take a more affordable route to replace your vehicle’s flex pipe. The average estimated labor cost for replacement is around $70 to $217.
An alternative option is to repair the exhaust flex pipe without having to replace it. This can be done when the pipe has become damaged through wear and tear. It’s possible to patch up a flex pipe that’s had its wire mesh come undone or has become cracked.
If you’re interested in giving it in a go, we’ve put together a quick guide that can help you DIY. Refer to the last section for the instructions.
What Is an Exhaust Flex Pipe Used For?
Flex pipes are differentiated from the rest of the pipes used in the exhaust system in that they are, in fact, flexible. They are used on vehicles with all-wheel drive and are especially useful on vehicles with front-wheel drive.
Located near the exhaust manifold and connected to either the catalytic converter or a piece of solid piping, the flex pipe is built to withstand the heavy pressure put forth by the engine when in use.
Besides reducing the engine vibrations, flex pipes also serve to isolate heat and reduce noise. They can compensate for thermal expansion as well as prevent hardness in exhaust systems.
Flex pipes are unique in appearance because they are covered with a mesh of braided steel. The weave pattern on a flex pipe is hard to miss when attempting to locate the part underneath the car.
There are three different types of exhaust flex pipes, although they don’t vary too much. Older cars may use non-lined flex pipes which, as their name suggests, lack an inside lining of protective mesh. These types of flex pipes cause extra whistling noises that can be annoying.
Braid-lined are the traditional woven type of exhaust flex pipes and work well in lowering noise and resisting excess heat.
The third type uses an interlock liner made out of an expandable stainless-steel hose instead of the braids. This type of exhaust flex pipe is able to reduce more noise and is stronger overall.
What Are the Symptoms of a Broken Exhaust Flex Pipe?
A flex pipe can corrode and break over time. This will cause the exhaust gases to seep out and it creates a dangerous environment because carbon monoxide and the hydrocarbons in the gas are toxic.
There are many symptoms that can indicate a problem with a flex pipe. Take a look at some of them below:
- Loud Engine Noises – One of the first symptoms that you should be able to hear right away are the strange noises coming from under the car hood. These will sound like hissing or tapping. An exhaust flex pipe may need to be replaced if it makes these noises when pressing the accelerator or during a cold start.
- Lowered Performance – If your exhaust flex pipe has a problem, you may begin to see changes in the engine performance. For example, the accelerator could act intermittently or slowly, and it will be less responsive. If left unchecked, the symptoms might begin to progressively worsen.
- Decreased Fuel Efficiency – You might notice that the vehicle already seems to not be running so well. If performance has decreased, fuel is being wasted. If not fixed right away, you’ll find yourself spending more on gas on top of having to deal with the irritation of the sluggish accelerator.
- The Smell of Burnt Rubber – Exhaust gases are very hot. A constant stream of these gases escaping from a hole in the flex pipe can melt plastic parts located under the vehicle. This can produce a burning smell and even smoke if left unrepaired for a long time. Always be on the alert for strange smells when nearby your automobile.
- The Smell of Gasoline – If you begin to smell gasoline inside the car, something may have gone awry with the flex pipe or the entire exhaust system. Always inspect the pipes underneath the car right away if the smell of gasoline is present.
How to Maintain Your Exhaust Flex Pipe?
Keeping all pipes in the exhaust system, including the flex pipe, in good condition involves preventive action whenever possible. The best way to keep your car parts well-maintained is to conduct visual inspections on a routine basis.
You can do spot checks daily – for example, a good morning routine would be to open the hood, check the battery, and engine, etc. It doesn’t need to take too long. For maintenance that requires disassembling a certain part of the car, you can save it for the weekend.
Don’t be afraid to bring your car to an auto shop for maintenance. Take the pressure and worry off your shoulders and place your trust in the mechanic. Automotive specialists will be familiar with your car type and can check every system in the vehicle from the brake lines to the air conditioning system. Additionally, they’ll take much less time doing it than you would.
The owner’s manual for your car is an extremely useful thing to have. You can find schematics, steps on how to perform specific maintenance procedures, locations of problematic system components, and other great recommendations for your vehicle type.
Don’t wait for small problems to become bigger. Once you spot a single sign of trouble, take steps right away to diagnose the vehicle. Be aware of the performance state of your car when driving.