What are intake manifolds?
An intake manifold, also known as the inlet manifold, directs the mixture of air and fuel to the right cylinder to be combusted so it can power the engine.
Additionally, the intake manifold conducts coolant through to the cylinders in order to reduce the temperature of the engine.
Attachment and maintenance
The intake manifold is attached to the top of the engine by the intake manifold gasket, which has to be monitored as it is susceptible to cracking under the heat and pressure and allowing coolant or oil to escape.
How does an intake manifold work?
The intake manifold uses pistons to conduct the air-fuel mixture and the coolant through the engine block via the valves to the relevant areas. It is important that these mixtures are distributed evenly, otherwise the engine will not work as efficiently. Here’s how it works step-by-step:
- Air Intake: The intake manifold draws in air from the vehicle’s air filter. This air is essential for combustion in the engine.
- Fuel Mixing: The air passes through the throttle body, where it mixes with fuel. In modern vehicles with fuel injection systems, fuel is injected into the air stream just before or as it enters the intake manifold.
- Distribution: Once the air and fuel are mixed, the intake manifold’s design ensures that the mixture is evenly distributed to each cylinder. It directs the flow into the cylinder heads through intake ports.
- Combustion: Inside the cylinders, the air-fuel mixture is compressed and ignited by the spark plug, which creates an explosion. This explosion forces the piston down, generating power to run the engine.
- Cooling: Some intake manifolds also conduct coolant through passages in the manifold, helping to regulate the temperature of the engine and prevent overheating.
The intake manifold’s role in delivering the air-fuel mixture and managing engine temperature is key for smooth engine performance and efficiency.
What causes intake manifold leaks?
Intake manifolds fail because of the high levels of constantly-changing heat and pressure they are subjected to on a daily basis. The strain they are put under inevitably leads to cracks developing – it is up to the driver to diagnose the problem and deal with it at the earliest opportunity.
What are the symptoms of intake manifold leak?
Symptoms of intake manifold failure can be difficult to identify as such, so it’s important that you are familiar with problems that might seem relatively minor, but which could be an indication of significant intake manifold issues.
The following can be symptoms of an intake manifold leak:
- Difference in air-to-fuel ratio resulting in backfires and rough idling
- Milky-looking engine oil
- Coolant leaking onto the ground under the vehicle while it is stationary
- Regular or quick engine overheating
- Poor fuel economy
- Decreased acceleration
- Engine misfires
How to repair an intake manifold
Repairing an intake manifold usually involves replacing the intake manifold or associated components. This can be costly and could be avoided by giving K-Seal a try first.
How much will intake manifold repair cost at a garage?
Although the cost of replacing an intake manifold will vary depending on the make and model of the car, many estimates have the cost of the part up to $300, with much of the cost of the job coming from labour and time spent on it. This can be a significantly higher sum – as much as $900 – and in some cars it may not be worth going ahead with the job.
Can K-Seal fix my intake manifold?
If there is a coolant leak then, in most cases, using K-Seal will help to quickly and permanently stop the leak, saving you a lot of time and money. Use our simple stockist search facility to find a bottle and get back on the road.
Could Other Parts of My Engine Be Affected?
Although your intake manifold could be the source of your engine troubles, it might not be the only component you need to take a look at. Select an engine part in the interactive diagram below to explore your engine and the important components that keep everything ticking over.
Still not sure what the problem is? Try our 60 second problem solver to quickly identify what the issue is based on your symptoms.