Can A Cracked Exhaust Manifold Be Welded? (Helpful Tips)

The exhaust manifold can get cracked eventually because of the stress from continuous and high-temperature changes.

Despite replacing the cracked exhaust manifold is also quite expensive, thus many vehicle owners think about welding. But can a cracked exhaust manifold be welded? If so, then how?

Following we have discussed whether you can weld your cracked exhaust manifold or not. And we include a simple and quicker know-how method for welding cracked exhaust manifolds.

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Can A Cracked Exhaust Manifold Be Welded?

Yes, it can be done. But it’s a slower process, and you can weld a cracked exhaust manifold using any welder suitable for steel. The key is to take the proper preparation, which will let you weld smoothly.

Some car owners use JB Weld ExtremeHeat to repair their cracked exhaust manifolds.

Though it’s a quicker solution, it won’t last for long. Since it’s possible to weld a cracked exhaust manifold and you’ve got the easy know-how process, taking risks won’t be wise.

How to weld a cracked exhaust manifold?

1. Take the cracked exhaust manifold out of the vehicle

Start by removing the cracked exhaust manifold from your vehicle. Welding the cracked exhaust manifold and keeping it on the engine can make the process extremely dangerous.

The reason is that there may be flammable chemicals. Based on the year, model, and make of the car, the removal process can take around 10 minutes to an hour or even more. Accessibility and space also affect the duration of the removal process.

2. Clean the manifold

Clean the cracked exhaust manifold with lime, calcium, or rust remover. Scour the manifold thoroughly so there are no longer any flammable chemicals. If they have any tough stuff, use a wheel or a wire brush to get it off. After cleaning the manifold, dry it properly.

3. Grind the cracked area

Grind the part where you need to weld. This way, you can remove the rust or debris from the cracked area and get a clean surface to create an arc.

But don’t grind excessive material away. You aim to make the manifold’s cracked area clean and prepare it for welding. If there are any hard to reach spots for the grinder, apply a wire brush to remove the contaminants as much as you can.

You should also grind the area where you will join the ground clamp. This practice will assure you of full power during welding.

4. Weld the cracked area

In general, the exhaust manifolds are made of very thick metal. So you may need to apply the full power of your welder machine, particularly if it is powered by a 110-volt house current.

You will aim to penetrate deep enough to properly repair the cracked area rather than patching up the surface. Start with a slower speed while placing the weld to make a big molten puddle.

If you are using a stick welder, you can reach almost all the areas of the manifold. Conversely, wire-feed machines can’t reach tight spots. However, if you can weld both the crack ends, they won’t travel further.

Another option is flux-core wire. For this unit, take the nozzle off to make a smaller gun so you can reach tiny areas.

5. Reinstall the manifold

After completing the welding, cool it down before putting the manifold onto the engine. Follow the suggested torque specifications from the manufacturer to bolt the manifold back up to the vehicle.

Check the gasket carefully to see if it has any damage. If you find any, replace the gasket. After installing the manifold to the exhaust system, you are ready to drive the car.

FAQs

Can I MIG Weld An Exhaust Manifold?

Professional mechanics don’t recommend MIG welding over any form of welding. But if your exhaust manifold is made of car iron, you can weld it with a MIG welder.

How Much Will It Charge To Fix An Exhaust Manifold?

Replacing the exhaust manifold is costs between $996 and $1,099 on average. In detail, the labor costs are between $248 and $314, and the price of the parts is around $748 to $785. This cost doesn’t include fees and taxes.

Can You Weld A Cast Iron Exhaust Manifold?

It’s possible to weld a cast iron exhaust manifold, but you can’t complete the project at a time. For a car’s iron exhaust manifold, you should weld an inch or less and then wait a minute to let it cool down. Low speed and a slower process are the keys to welding cast iron metal.

Final words

You can weld your cracked exhaust manifold using a typical welder suitable for steel. Still, if you are nervous about removing and re-installing the cracked exhaust manifold or operating a welder, take the vehicle to an auto shop.