What Causes an Exhaust Manifold to Crack or Leak?

Your car has two manifolds – an intake manifold and an exhaust manifold. Both serve essential purposes, but the one most likely to experience problems over the long term is the exhaust manifold. Depending on your make and model, your manifold might be a single piece of cast iron with channels/ports built into it, or it could be a collection of pipes tied together. The basic job of the exhaust manifold is to take the gases from each cylinder and send them to the exhaust pipe.

Why manifolds crack and leak

As you can imagine, exhaust manifolds are subject to intense heat. They’re also subjected to considerable expansion and contraction as they heat up and cool back down. Over time, this leads to metal fatigue (both cast iron and other types of exhaust manifolds are subject to this). As the fatigue becomes worse, it’s possible for the manifold to develop cracks.

Another potential problem lies with the exhaust manifold gasket. The gasket sits between the manifold and the engine block, and is designed to seal the small gap that exists between these two components. Like the manifold itself, the gasket is subjected to significant heat, as well as expansion and contraction. It will eventually fail (this is normal, and cause by nothing more than general wear and tear). When it fails, it will begin to leak.

Problems associated with manifold cracks and leaks

There are several problems created with exhaust manifold cracks and leaks. First, hot exhaust gases are now being vented under the hood, rather than being sent downstream through the exhaust pipe. This can damage plastic components in the engine bay. It can also become a health hazard, as the exhaust fumes can enter the car’s cabin.

There’s also the possibility that it will affect engine performance. If your exhaust manifold is cracked or leaking, the back pressure in the exhaust system will be incorrect, which can reduce engine power, cause sputtering and other problems. Of course, you won’t pass emissions testing, either.


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Recent Exhaust Manifold Repair reviews

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Brian

24 years of experience
157 reviews
Brian
24 years of experience
GMC K1500 Suburban - Exhaust Manifold Repair - York Springs, Pennsylvania
Brian was absolutely the best most professional mechanic I ever hired. I would most definitely ask for his services again.
Saturn Vue - Exhaust Manifold - Frederick, Maryland
Finding Your Mechanic and especially Brian was exactly what I needed. Brian is very friendly and knowledgeable. With my busy schedule, this service is super convenient with Sunday hours. I just don't have time to spend in a shop or dealership. Brian's work is top notch and less expensive than taking my car to a dealership.

Jason

23 years of experience
190 reviews
Jason
23 years of experience
Chevrolet Malibu - Exhaust Manifold - Nashville, Tennessee
Jason was nothing but professional and courteous throughout the process. I would absolutely recommend his service!
Chevrolet Malibu - Exhaust Manifold - Nashville, Tennessee
Jason did fantastic job!!!! Jason arrived 30 mins ahead of time. Fix my exhaust manifold very quickly. Very knowledgeable about fixing the problem. You can tell he is great at what he does. I will give him 10/10. Will be asking for more his services again very soon. Just Awesome very pleased with the job.

Johnathon

9 years of experience
113 reviews
Johnathon
9 years of experience
Toyota Corolla - Exhaust Manifold - Fresno, California
Jonathan is a very nice and knowledgeable person. He did a great job on my daughter’s vehicle. I will continue to use him in the future and also refer him to others as well. Thank you

Fernando

11 years of experience
19 reviews
Fernando
11 years of experience
GMC Terrain - Exhaust Manifold - Lake Stevens, Washington
Fernando was absolutely amazing. My wife's car came out great. He went above and beyond to make sure the right parts were right and explained every step.

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