How to find exhaust manifold leak?

As part of the engine system, the intake manifold is a part that helps distribute air to the cylinders. As such, it plays a critical role in starting your vehicle. Over time, however, it can become compromised. A leaking intake manifold can have a major impact on the operation of your vehicle.

Most exhaust manifolds are made of strong cast iron or stainless steel. But over time, a manifold can warp or crack due to thermal stress, resulting in an exhaust leak. Exhaust leaks can also result from faulty manifold gaskets and broken mounting bolts.

What are the symptoms of intake manifold leaks?

There are several possible symptoms of an intake manifold leak:

• Failure to accelerate
• Coolant leaking from the intake manifold
• Excessive fuel consumption
• Increased pollution
• Irregular idle
• Check engine light illumination
• Difficulty starting
• Engine overheating

These symptoms are not specific to an intake manifold leak. To be sure this is the problem, there are a few things you can check.

How do I locate an exhaust manifold leak?

An exhaust manifold leak can often be found by listening and visually inspecting the vehicle.

First, start the engine cold and listen for the telltale ticking or knocking sound of an exhaust leak. Once you've traced the sound to the manifold, look for confirmation of an exhaust leak, such as soot spots and missing bolts. Components (such as spark plug wires) near the exhaust leak may also melt.

The exhaust manifold might need to be removed to check for failure. Once the manifold is removed, you can visually inspect it to see if it has cracked and needs to be replaced.

If you don't see any cracks, you'll want to check the manifold for deformation using a precision ruler and a blowtorch.

The first step is to clean the manifold of any old gasket material. Next, place the ruler on top of the manifold. Shine your flashlight where the manifold meets the ruler. If the manifold is warped, you'll see the light shining from under the ruler.

Also, connect the vacuum to your car's exhaust pipe, turn on the vacuum, and start spraying soapy water around the exhaust manifold, downpipe, catalytic converter, muffler, and gaskets. Bubbles will form around the leak.

Once you've located the leak, decide if you can or want to fix it yourself.

Exhaust Manifold Removal

Use these steps to remove the exhaust manifold:

1. Before removing the mounting bolts or nuts, apply a good quality penetrating oi
2. Allow the oil to penetrate for a few hours each time. Follow the instructions that came with the product. This will help you remove the exhaust bolts and avoid damaging them.
3. Make sure the engine is cold and disconnect the battery.
4. Put the transmission in park (automatic) or neutral (manual).
5. Apply the emergency brakes.
6. You may need to lift the front of your vehicle to access the mounting bolts under the manifold. Support the vehicle securely on stanchions.
7. As you remove the mounting hardware, check for loose or broken bolts, nuts, or studs. This could be an indication of the source of a leak.
8. Loosen the mounting bolts and nuts gradually, starting from the center of the manifold and working outward, alternating the bolts on the left and right sides. Do this in three or more passes, loosening all the bolts a little at a time, then doing a second pass, and so on until you have removed all the mounting hardware.
9. Once you've removed all mounting hardware, you may need to tilt the manifold up and down to loosen it from the cylinder head. Do not use a screwdriver or similar prying tool to remove the manifold. You could damage the mating surfaces and result in a very expensive repair.

What can cause an intake manifold to leak?

There are several possible causes:

• Loose intake manifold bolts or damage to the intake manifold: If your vehicle's intake manifold is damaged, it can cause leaks around the coolant ports. The result is a buildup of corrosion that eats away at the plastic around the ports. Intake manifolds are also prone to cracking, especially if they are made of plastic.
• Disconnected or disconnected intake hose: The intake hose may have been disconnected during work to repair or replace an engine component. Over time, this part can also become damaged and cause leaks from the intake manifold. This is especially true if you have driven several thousand miles in extreme conditions (bad weather, oil spills, pressure, etc.).
• Manifold gasket wear: The main function of the manifold gasket is to prevent unmeasured outside air from entering the engine. Depending on the type of engine, it may even prevent coolant or oil from escaping from the cylinder head or combustion chambers.

An intake manifold leak is a very serious problem that can occur during the life of your vehicle. It can cause more serious problems such as difficult or impossible starting, engine overheating, etc. At the first sign of trouble, see a mechanic. Don't delay!