The signs of a cracked intake manifold
A cracked intake manifold on your vehicle is a serious problem that can lead to expensive repairs. If you suspect your vehicle has a cracked intake, you should stop driving it and have it towed to a repair shop as soon as possible to avoid doing further damage to your vehicle.
There are a number of signs to look for if you suspect that your vehicle has a cracked intake manifold.
Missing and Hesitating
If your vehicle's intake manifold is cracked, it will affect the air and fuel mixture in the engine and disrupt the normal combustion process. The engine may miss, hesitate, stall or just generally seem to run poorly if your car has a cracked intake manifold.
A cracked intake manifold will allow the gases in the intake to escape, sometimes quite noisily. As the engine runs, especially at high speeds, it will put more pressure on the intake manifold. If your vehicle's intake manifold is cracked, the pressure can force air through the crack and cause the motor to make a loud whistling or hissing noise.
A cracked intake can cause your vehicle's coolant to leak. Under normal circumstances, the coolant is kept in check by the intake manifold gasket. However, if the gasket or the actual intake manifold fails, coolant can get into the engine and cause serious mechanical issues. A good indication that this has happened is when your vehicle starts overheating due to lack of coolant.