As mornings get cooler, a lot of drivers start hearing a ticking or tapping sound right after they start the engine. It’s often loudest for the first few minutes and then fades away as the car warms up. Many people assume it’s an engine problem, but very often the cause is an exhaust manifold leak.
The exhaust manifold is the first part of your exhaust system. It bolts directly to the engine and collects the hot exhaust coming out of each cylinder. Because it sits right against the engine, it goes from cold to extremely hot every single time you drive.
All that heating and cooling takes a toll. Over the years, the manifold can crack, the gasket between the manifold and the engine can burn out, or the bolts holding it on can loosen or break. When that happens, small puffs of exhaust escape with each pulse from the engine, and that’s the ticking you hear.
The reason it often goes away once the car warms up is that the metal expands with heat and temporarily closes the gap. On a chilly fall morning, the gap is at its widest, so the noise is at its loudest.
A manifold leak is worth fixing even if the sound fades. Hot exhaust escaping near the engine can damage nearby wiring and parts, throw off your oxygen sensor readings and lower your gas mileage. Exhaust fumes from a leak this close to the engine can also find their way into the cabin through the heater.
Manifold work can be tricky. Bolts that have been heated and cooled for years are often rusted in place and can snap if they’re forced. It’s the kind of job where experience really matters, and it’s exactly the kind of work Dallas specializes in.
If your car has started ticking on cold mornings, let us take a listen. Call Stones River Auto and Exhaust at (615) 961-6322 or stop by 1601 Flat Rock Rd in Murfreesboro, Monday through Friday from 8 to 5.
