Fix It

A hissing noise coming from the engine of your vehicle combined with liquid spillage from the car can mean trouble for your vehicles exhaust or intake manifold. Such signs can be symptomatic of a manifold leak, which is when your exhaust or intake manifold leaks oil or coolant. If you notice a manifold leak, its important to stop the leak immediately because it can pose a hazard to the passengers in the vehicle.

Repairing the Manifold

If the manifold is leaking due to damage to the exhaust or intake manifold, or the general wear and tear of it, then the most effective way to stop the manifold leak is to repair and replace the manifold. A manifold can be removed from the vehicle and replaced with something new so that the vehicle no longer leaks. If the manifold just has some small cracks in it that are causing the leak, another repair alternative is to have the cracks welded together rather than purchasing and installing a new manifold.

New Gasket

A new gasket that seals the manifold is one way to stop a manifold leak. If a gasket is cracked, it is no longer able to seal and maintain the connection with the manifold, thereby creating a gap between the manifold and the exhaust pipe. Shear stress to the gasket of the manifold is part of the normal wear and tear of the vehicle due to the thermal contraction and expansion that happens each time the engine is turned on and off.

Sealant Solution

You can try to stop a manifold leak by coating the gasket or manifold with a leak sealant. Leak sealants, which are available at auto repair shops, are applied directly onto the affected area of the vehicle and act as a means of sealing the leak so that no more fluid can be lost. This solution is simpler than attempting to replace the manifold or gasket.

Accurate Assessment

A manifold leak can only be stopped if youve isolated the problem accurately. If you misdiagnose the cause for the leak, or think its the exhaust manifold when its really the intake manifold, then you risk prolonging the repair and, meanwhile, the vehicle continues to lose fluids. An accurate assessment is necessary for stopping a manifold leak, so its important to learn how to diagnose and troubleshoot the problems and locate the source of the leak.

A sure sign of air conditioning problems is a lack of cool air coming out of the vents in your van or other vehicle. The problem might be with the compressor or motor, but it might just be a leak. The leak might not be your only issue, but it must be addressed before fixing any other components of the air conditioning system.

Instructions

1

Look in your vehicles owners manual to determine what type of rigerant your van uses.

2

Set the rigerant leak-detector to the appropriate setting. The setting varies based on the type of rigerant your vehicle uses. It is typically labeled CFC, HCFC or HFC, and must be set correctly to locate the source of the leaks.

3

Move the rigerant leak-detectors sensor along the air conditioning hoses and other components, looking for the indicators of a leak. The indicators vary in different rigerant leak-detectors, but are often represented by a buzzer or other sound.

4

Pay special attention to connection points. Move the sensor across all sides of the hoses and other components.

5

Mark each leak with masking tape. This allows the mechanic addressing the leaks to easily locate it.

One of the most important functions of a cars exhaust system is to protect the occupants of the vehicle from hazardous fumes. If the exhaust system leaks, carbon monoxide and other waste gases can collect in the cabin and harm or kill the passengers. Because of the abuse and exposure suffered by the exhaust system, faulty or leaking parts are usually replaced. If the exhaust system is sound enough, it can be repaired.

Braze Welding

Braze welding is a way to join two metals with different melting temperatures. The filler metal has a lower melting point than the base metal. Small holes in a muffler may be patched by braze welding filler material into the holes. Larger holes in a muffler may be repaired by braze welding patches of steel over the holes.

Brazing

Brazing is similar to braze welding in that the filler material has a lower melting temperature than the base metal. The difference between brazing and braze welding is that in brazing the filler metal is drawn into the joint by capillary action. In plumbing, this process is called "sweating" a joint. Exhaust pipes can be repaired at the joints by brazing.

Why Does the Shop Want to Replace Instead of Repair?

Repairs to any metal can only be done where the metal is in good shape. The exhaust system of a car is subjected to abuse from both the inside and the outside of the system. The temperatures of exhaust gases are high enough to weaken any metal. Cars driven in areas that use salt to clear snow from the road can suffer corrosion very quickly. If an exhaust system is more than two or three years old, it probably is not a candidate for repair.

Benefits of Braze Welding or Brazing

Joining metals with either a brazed or a braze-welded joint can result in a stronger joint than traditional welding because of the difference in melting points between the two materials. If steel is heated to near its melting point then allowed to cool slowly, it becomes weak. With either of these techniques, the steel never gets hot enough to be damaged.

The exhaust system on your Ford F150 consists of the exhaust manifold, exhaust pipe, catalytic converter, muffler and tail pipe. With the exception of the tailpipe, all of these components are sealed together with gaskets. A leak in any of the gaskets will allow exhaust gases to escape from the system. Because the exhaust gases are no longer completely travelling through the muffler, they are no longer quieted or "muffled." This results in a louder exhaust note.

Instructions

1

Raise the hood of your F150 and start the engine. Locate the source of the exhaust leak by listening along the exhaust system. Do not use your hands to feel for the leak, as this will burn you.

2

Turn the vehicle off and allow the engine and exhaust to cool before working on it.

3

Return to the area of the exhaust leak. The most common area for an exhaust leak is where the exhaust manifold meets the exhaust pipe. If this is where the leak is, remove the bolts from the pipe mounting flange, by turning them counterclockwise with the socket. Install the new gasket, which is referred to as a "doughnut" because of its shape, and tighten the flange bolts by turning them clockwise.

4

Inspect the area where the exhaust manifold bolts onto the engine. If the leak is here, try to tighten the manifold bolts by turning them clockwise with the socket. This will often seal the leak. If this does not work, remove the manifold bolts by turning them counterclockwise with the socket. Pull the exhaust manifold from the engine and remove the mounting gasket. Use the gasket scraper to remove any gasket residue. Put the new gasket into place and tighten the manifold bolts, by turning them clockwise with the socket.

5

Inspect the catalytic converter flange and the muffler attachment for leaks. If any are found, remove the mounting bolts by turning them counterclockwise with the socket. Install the new gasket and tighten the mounting bolts by turning them clockwise with the socket.

The exhaust system is an important part of your vehicle, because it expels burned engine gases from the car. The exhaust also controls emissions of your vehicle, and any damage or leaks to it can affect the performance of the car. Poisonous carbon monoxide can seep into the passenger area, which is why it is important to diagnose and repair exhaust leaks right away.

Physical Damage and Leaks

Perform a visual examination of the vehicle and its exhaust system for signs of physical damage or scrapes. Look for signs of black soot on the exhaust and tailpipe, which is a sign that there is carbon built up from a leak.

Scraping the bottom of the car while driving over a curb or speed bump is a common way to cause damage to the exhaust. Holes and scrapes can cause the exhaust to start leaking.

The oxygen sensor is in the exhaust system, and scraping the bottom of the vehicle can damage the oxygen sensor, which will cause exhaust leaks.

Check your vehicles undercarriage for signs of rust. Older vehicles are vulnerable to rusting, and rust will eat metal, causing leaks in the exhaust pipe.

Welded joints are common spots for exhaust leaks. Check all joints on the exhaust and make sure there is no rust or damage.

Shaking and Noise

Vehicles with an exhaust leak will shake and rattle while idling at a red light. A different noise, such as a ticking or popping, is a common sign of an exhaust leak. A loud roaring noise that is different from the usual sounds your car makes is also a sign of an exhaust leak problem.

Have a friend gently accelerate the engine while you have the hood up and are listening outside the vehicle. Listen for a deep, throaty sound or loud sputtering that sounds different from what you are used to hearing from the car.

Gas Smell

Smelling a gas while your cars windows are rolled up is a sign of an exhaust leak. This sign is often easier to notice in colder months when you drive with the windows up and the vents are opened for hot air. The odor may not be noticeable while you are outside the vehicle but is always present as you are driving.