Chevy heat riser valves work to make an engine's cold-starting abilities easier and quicker. Chevy riser valves can be helpful, but can also cause problems if they become stuck open or closed.
The Chevrolet Heat Riser valve is a control valve between the exhaust manifold and exhaust pipe on the side of a V-8 or V-6 engine. The valve is designed to warm the carburetor and fuel to aid in fuel evaporation and speed engine warm-up.
The heat riser valve blocks the exhaust flow from the vehicle's cylinders, pushing it back up through the engine. It then moves the exhaust through a small cross port in the intake manifold, into the carburetor base and out the opposite side of the engine.
A heat riser valve can become stuck open or closed, which can cause problems. A valve stuck open will result in slow engine warm-up. This can cause hesitation and stalling. A valve stuck in the closed position will restrict the exhaust system, causing a lack of power and drop in fuel efficiency.
