Does your car feel much slower than normal and do you have a flashing check engine light on your dashboard? Then there is a big risk of your car suffering from a boost leak.
A booster leak can cause many different strange symptoms. There are a few worth taking a closer look at to identify a booster leak. But what is a boost leak and what are the most common symptoms? Let’s take a quick look at the signs:
The most common symptoms of a boost leak are loss of power and a check engine light on the dashboard. You may also notice signs such as a sluggish turbo spool, poor fuel consumption, and black smoke coming out of the exhaust pipe during acceleration.
Although these are just a few of them and not the entire list, it is perfect for a quick overview. Fortunately, here is a more detailed list of the six most common symptoms of a boost leak.
Increase leak symptoms
1. Slow turbo coil
The turbo works by increasing the amount of air and fuel that can be put into a cylinder, thus increasing power and performance. However, before the turbo comes into action, its turbine must rotate very quickly. Until that happens, the turbo plays no role in improving the car.
This problem, commonly known as turbo lag, occurs when the turbo spools air and fuel to be sent to the cylinder. If this process is slower than normal, you are experiencing a boost leak. The concept is simple: Due to a leak, the turbo takes longer to fill the booster tubes.
2. Loss of power
As you accelerate, the turbo creates pressure in the boost tubes to make the car run better. If there is a boost leak, it will take longer to fill these pressure hoses, and the pressure will be lower than normal.
This will cause a drastic loss of power in your car’s engine. If the leak is large, it may even mean that you are losing all turbo pressure.
3. Check engine light
The check engine light monitors all of the sensors in a car’s engine, including the boost pressure sensor.
If there is a problem with the turbo boost pressure, which will be incorrect if you have a boost leak, the check engine light will come on.
If you see a check engine light on your dashboard, look for trouble codes with an OBD2 scanner.
4. Black exhaust smoke
The MAF sensor measures the air entering the engine. If there is a leak in the hoses between the MAF sensor and the engine, the air loss will be measured.
This will result in a lean air-fuel mixture and, in most cases, a rich mixture. A mixture that is too rich will cause black smoke to come out of the exhaust. So if you experience black smoke from the exhaust when accelerating, it’s definitely time to check for booster leaks.
5. Poor fuel economy
The same applies to fuel consumption regarding boost leaks and MAF sensor measurements.
It may not be very easy to distinguish, but if you look at the average fuel economy of your car, you will easily spot a boost leak.
If the car is consuming more fuel than it should, you have a problem. A booster leak test can be helpful in such situations.
6. Bad idle
This only applies if you have a car with a mass Air Flow or MAS/MAF sensor. The MAF detects the amount of air leaving the turbo and entering the engine.
If there is a large boost leak, your car will have trouble idling perfectly. It could become stagnant and close due to the leak.
It is not very common with a bad idle due to a leak in the boost pipe, it is more common if the leak is in the intake manifold behind the throttle body, but may be true if it is a large leak.
What is a boost leak?
A boost leak is a type of air leak in the intake path just before the engine cylinders. It’s basically a loose clamp or a damaged hose that can’t handle the pressure of the turbo.
Ignoring a boost leak will eventually shorten the life of your turbo and therefore the life of the car’s engine.
The ECU determines the air/fuel ratio; However, if there is an air leak in the way, the ratio is miscalculated.
Diesel engines are suited in this regard as they are better at tolerating a high fuel to air ratio. However, gasoline engines are sensitive. Therefore, a booster leak inspection is necessary for optimal performance of your car.
How to find a booster leak
You can try to find the boost leak the hard way or the easy way.
To easily find a boost leak, you should use an EVAP smoke machine. With this type of device, you will find booster leaks in no time.
The machine is pressurizing the booster hoses with smoke, and if smoke is coming from anywhere in the engine compartment, you most likely have a booster leak there.
If you have a small workshop, it’s definitely time to invest in one. You can see my recommendations for EVAP fog machines here: Best EVAP fog machines.
The hardest way to find a boost leak is to try to find it visually. Check all hoses and booster pipes to make sure none have come loose.
You can also try carefully pressurizing the engine booster hoses with compressed air if you have an air compressor. Be very careful, however, as the engines work very well with pressurized air. Make sure the wheels are in the air so they don’t start rolling through pressurized air, and be very careful with the pressure.