So Fix it

Exhaust flex pipes are a flexible metal pipe sections that are used either in areas where an exhaust pipe needs to be flexible, or to repair a damaged exhaust system. While they are all-metal, it is common for one to fail and require replacement.

Construction

Automotive exhaust pipes get extremely hot from the exhaust gas passing through the system and out the tailpipe. Due to this, when an exhaust system needs to bend, shift or be flexible, the manufacturer cannot use traditional materials like rubber. The flex pipe is made of metal strips woven into a lattice, and thus can withstand exhaust gas heat. Higher quality flex pipes will be made of stainless steel.

Use

Automotive engines move slightly during operation, whereas most exhaust systems are fixed from the mid-section back. Flex pipes allow the engine to move and not crack or rupture what would otherwise be an inflexible metal exhaust pipe. Flex pipes are typically found where the exhaust manifold meets the downpipe or mid-section of an exhaust, which is closer to the engine than to the exit tailpipe.

Availability

Exhaust flex pipe sections are widely available at automotive stores in a variety of lengths and diameters.

Fumes created by your automobile during fuel burning are expelled from the engine by the exhaust system. The exhaust pipe, or tailpipe, is where fumes exit the car. Many car improvement jobs involve replacing rusted or broken pipes. It is important to know the exact diameter of the pipe that fits the rest of the exhaust system when replacing it. This process is complicated by the location of the exhaust pipe, and often by its angle of cut on the pipes end.

Instructions

1

Raise your car using a car jack to a height that will allow you to lie comfortably underneath the vehicle.

2

Open the clamps of your caliper, and place them around the outside of the exhaust pipe. Choose a portion of the pipe that is straight. Close the caliper clamps around the pipe securely, but not tight enough to dig into the metal of the pipe. Record the reading on the calipers on a piece of paper.

3

Stick one clamp arm of the caliper inside the end of the tailpipe, leaving the other clamp arm outside the pipe. Close the clamp around one wall of the pipe, measuring the pipes thickness. Read the caliper and record this number.

4

Multiply the pipes wall thickness by 2. Subtract this number from the total outside pipe diameter determined in Step 2. This remaining number is the inside diameter of your exhaust pipe. The full equation is:

Inside Diameter = Outside diameter - (2*Wall Thickness)

Adding a custom exhaust to your car is a good way to gain horsepower and a more aggressive tone to the exhaust at the same time. You could go out and buy a bolt-on system for your Altima, but if you want to truly customize, youll have to step up and have an exhaust built for you. First, though, youll want to find out what size your Altimas exhaust tubing is. That way you have a baseline to use as you determine how much you want to go up.

Instructions

1

Lift the Altima using the jack and place it on jack stands at all four corners. Make sure there is enough room for you to crawl underneath the car.

2

Locate the section of exhaust tubing that you want to measure. Open the calipers and place them over a straight section of exhaust tubing. Then tighten down the caliper until it contacts the exhaust all the way around.

3

Read the dial or digital gauge on your caliper to find out the approximate diameter. Exhaust tubing sells in average sizes: 2.25 inches, 2.5 inches, 2.75 inches, and so on; there are no odd sizes. Round the number on your caliper down to the next quarter size down, and thats your exhaust tubing diameter.

The corrosive effect of accumulated moisture, vibration and impact damage from road debris makes eventual muffler and exhaust pipe replacement a foregone conclusion. Depending on the model year and the exhaust configuration of your Chrysler 300---dual or single tail pipes---replacing the exhaust pipe involves disconnecting the exhaust pipe from the catalytic converter, loosening the hanger brackets that support the exhaust system and removing the mufflers and exhaust pipes from under the vehicle.

Instructions

Exhaust Pipe Replacement

1

Set the emergency brake and chock the rear wheels with wood blocks. Then, jack the car up on a hard, level surface making certain that the lifting point is a load bearing part of the car chassis and that the vehicle is high enough off the ground to allow easy access to the exhaust system. Position jack stands under the appropriate chassis contact points and ratchet them up to just touching. Now, slowly lower the car onto the jack stands.

2

Position the jack under the muffler and raise the jack to support the muffler before releasing the exhaust pipe from the chassis hangers. Double-check that you have purchased the correct replacement exhaust for your Chrysler 300 model. The typical configuration will have a catalytic converter in the exhaust line on each side of the block feeding by way of a cross-over pipe into a single muffler.

3

Disconnect the oxygen sensors from the exhaust pipe ports near the catalytic converters. Unscrew the two nuts on each U-bolt connecting the exhaust pipes to the back of each catalytic converter. The catalytic converter is the cigar-shaped emissions control device installed in the exhaust system, closest to the engine. Unless you have experienced a loss of power, can smell a sulfur odor or feel heat radiating from the car floor, your catalytic converters are probably okay.

4

Inspect the two mufflers for rust. If the exhaust pipes are rusted badly, the mufflers are ready to be changed, as well. With the car jack positioned under and against the larger muffler, the one closest to the motor, disconnect the exhaust pipe brackets from the support hangers and lower the entire assembly to the ground. To loosen rusted nuts and bolts, apply liberal amounts of WD-40. Give the penetrating oil a few minutes to soak in, then remove the nuts. If the pipes are rusted into the catalytic converters, rap them with a hammer to break the rust loose, but make sure that you are wearing safety glasses when you do this.

5

Assemble the new mufflers and exhaust pipes, on the ground, using the four new U-bolts provided to secure the pipes in each muffler port. Use the old assembly as a guide and compare them side by side for proper length. If you purchased an original equipment manufacturer replacement, the new assembly should fit properly. Check the hangers and hard rubber noise dampers for wear, and replace if necessary.

6

Position the new unit under the car and use the jack to raise it into position. Then, reattach the exhaust pipe brackets to the hangers and reconnect the exhaust pipes to the catalytic converter with two new U-bolts. Dont forget to tighten all the connections and reattach the oxygen sensors. When youve done this, jack up the car, remove the jack stands and slowly lower the car to the ground.

There are two schools of though regarding optimal efficiency for an exhaust pipe. Some would argue that an exhaust pipe should be short because of its aesthetic appeal. The other school of thought argues that longer tailpipes are better because they provide greater power curves and more overall engine power. There are two pieces of information that you must obtain in order to calculate the proper length of an exhaust pipe for your vehicle.

Instructions

1

Determine the center RPM values for your desired power curve. In other words, what will be the RPM amount for your average speed in the car? In general, motorcycles will be between 4000 and 5000. Cars will be between 650 and 800.

2

Calculate the opening point of the exhaust valve. The opening point is recorded in degrees before bottom dead center (BBDC). The default valve opening for a motorcycle is 43 degrees. The default opening for a car is 90 degrees.

3

Plug the two values into the exhaust length calculator program from the resources section of this article to get your result.

To bend steel pipe, you need to apply heat evenly to the entire area that you need to bend. The main problem with bending pipe without a tubing bender is kinking the pipe. If the pipe kinks, it will lose its structural integrity. The kink will restrict the flow of water if it is a water pipe; if it is steel pipe being used as electrical conduit, you will have a problem fishing the wires past the kink. To avoid kinking the steel pipe, you must support the walls of the pipe while you perform the bend.

Instructions

1

Cover one end of the steel pipe with two layers of duct tape. Secure the loose ends of the duct tape with more tape.

2

Stand the pipe on end, with the taped end resting on the floor, and fill the first 12 inches of the steel pipe with damp sand.

3

Pack the damp sand with the tamping rod and add more sand to the steel pipe. Continue the process of filling and packing the sand in the steel pipe until the entire length of pipe is filled with damp sand.

4

Cover the open end of the steel pipe with duct tape to contain the sand within the steel pipe.

5

Secure the sand-filled steel pipe in the vise, with the area of the steel pipe you need to bend extending out past the end of the vise.

6

Light the oxy-acetylene torch and set the torch to burn a neutral flame. A neutral flame will have a blue exterior flame with a short bright blue interior flame that does not emit any black soot.

7

Evenly heat the entire area that you need to bend by running the neutral flame of the oxy-acetylene torch around the entire circumference of the steel pipe until it emits a low orange glow.

8

Apply pressure to the end of the steel pipe and start bending the steel pipe; keep applying heat to the bend area while you are bending the steel pipe.

9

Allow the steel pipe to cool and then remove the steel pipe from the vise.

10

Remove the duct tape from both ends of the steel pipe and tap one end of the steel pipe on the ground to remove the tamped sand from the steel pipe.

11

Use the water hose to run water through the steel pipe to remove any sand that remains in the steel pipe.

12

Wipe the pipe dry with a clean rag.

It used to be a lot easier before the days of catalytic converters and resonators and other complicated and integrated exhaust components to repair a cracked muffler pipe. Now the exhaust systems contain many variables that create difficulty when trying to attempt simple repairs. However, with this in mind, the aftermarket exhaust industry has also found some clever ways to work around the complicated systems. If you do indeed have a cracked muffler pipe, you may have some options left before you have to spring out the cash to replace the entire system.

Instructions

1

Lift the vehicle safely and securely on a car lift.

2

Put on the safety glasses.

3

Locate the cracked muffler pipe.

4

Put on the welding shield and weld the cracked muffler pipe if the crack is located on a bend in the pipe and a sleeve clamp or buddy sleeve would not be a viable option.

5

Use the sleeve clamp to cover the crack in the muffler pipe if the crack is small, located on a the seam of the pipe, or if the pipe is broken in a straight section of the muffler pipe. Wrap the clamp around the cracked pipe, place the nut and sleeve brace on the other side of the bolts, and tighten using the ratchet, socket and a hand wrench.

6

Use a buddy sleeve to reconnect a separated muffler pipe. This would only be an option if the pipe was completely broken in half on a straight section of the muffler pipe. The buddy sleeve would reconnect the two halves of the pipe and you would use to exhaust clamps of suitable size to tighten the buddy sleeve to the cracked muffler pipe.

If you just noticed a sudden increase in volume from your cars exhaust, you probably have had a hole rust through or puncture your exhaust pipe. This hole will affect your vehicles emissions and also continue to make your exhaust louder than usual. The best way to fix this hole is to replace the broken part, but if you need a quick fix a muffler patch is a great temporary solution.

Instructions

1

Locate the hole in your exhaust system. If it is not readily visible turn the car on and try looking for the vapor escaping or tracing the louder noise.

2

Purchase a muffler hole repair kit at your local automotive store.

3

Turn off the car and jack it up if necessary to reach the hole.

4

Wrap the muffler tape around the muffler or hole completely and cover the hole totally with several layers of the tape. The tape is self adhesive usually or is activated by the mufflers heat and will keep itself on securely.

You dont want to drive with a rusted-through exhaust pipe dragging noisily on the road. Before you get to the muffler shop, heres what to do with an exhaust pipe that is about to fall off.

Instructions

1

Wait for the engine to cool down so the exhaust pipe is cool enough to touch. Place your hand near the pipe to gauge how hot it is before actually touching it, or wrap a thick rag around your hand.

2

If part of the pipe is about to fall off, remove the hanging part by bending and twisting it until it breaks free. You neednt reattach it, since you must have it replaced or welded on at a muffler shop anyway.

3

If you cant break off the hanging pipe, untwist a wire coat hanger or use some mechanics wire (available at an auto-parts store). Wrap one end around the hanging pipe and fasten the other end to the underside of the car. Do not wrap the wire around the drive shaft or anywhere where it risks becoming tangled with the drive shaft. Wrap it around a stationary part underneath the car.

4

Make an appointment at the muffler shop.

Oil on the exhaust manifold or blue smoke spewing out of the tailpipe is commonly caused from a compromised gasket or cracked exhaust manifold. The head gasket is the main seal protecting the engine cylinders from engine oil. A compromised head gasket or O-ring will allow oil into the cylinders and exhaust manifold piping.

Exhaust Manifold Function

The exhaust manifold is secured directly to the individual engine cylinder ports. Exhaust gases expel from the combustion chamber into the exhaust manifold before moving towards the tailpipe. There must be an airtight seal between the manifold pipes and the cylinder ports.

Blue Smoke

Blue exhaust smoke may be coming from your tailpipe. Blue smoke indicates oil in the cylinder ports and then exhaust manifold -- a sign that a gasket or O-ring protecting the cylinders from oil has failed.

Diagnosing A Compromised Exhaust Manifold

Oil commonly enters the inner portion of the exhaust piping after leaking through the cylinder ports but it is possible for oil to find its way onto the external portion of the piping. This occurs one of three ways: a crack in the manifold piping, a compromised exhaust manifold gasket or a blown oil seal. In any case, an engine oil seal has failed.