How a Vacuum Leak Affects Your Engine’s Performance

April 1, 2021

Vacuum is more important to your automobile’s engine than you realize. Your automobile uses a vacuum that is produced in the combustion chamber to power accessories and components. If you end up with a vacuum leak through one of the vacuum hoses, your vehicle’s performance will be affected. Pit Shop Auto Repair lists the signs of a vacuum leak below so you know what to look for in your car, truck, or utility vehicle.

Acceleration Performance Loss

One thing that happens when you have a vacuum leak in the engine is that the leak itself introduces more air into the engine’s environment. This can turn a normal fuel mixture into a lean one, i.e., one that is richer in air than in gasoline. Consequently, your engine will be fuel-starved, and it may be hesitant to respond when you press down on the accelerator to pick up speed.

Dashboard Warning Light

This change in the engine’s environment might also cause the engine control module to turn on the check engine light on your vehicle’s dashboard. This is because the engine control module has been advised that there is a problem in the combustion chamber by one of the many sensors found in your automobile’s engine. The check engine light won’t turn off until you get the vacuum leak fixed.

Hesitating Engine That Stalls

Aside from the acceleration problems discussed above, you may also have problems while your car, truck, or UV is in motion. Your engine may sputter or hesitate. It may hiccup and misfire. In severe cases, the engine will stall. This, again, is because there is too much air in the engine and not enough gasoline. The air is outweighing the fuel and causing these performance issues.

Hissing or Sucking Sounds

Depending on how big of a vacuum leak you have, you may be able to hear it. In most cases, vacuum leaks make hissing or sucking sounds. Many people we have talked to describe the sucking sound as that of the vacuum hose, and we find that to be true here in our shop, too.

RPMs That Are Higher Than Normal

If you happen to notice the needle dancing on your tachometer, this is a sign that the engine is getting spurts of air through a vacuum leak. Often times when the engine has a vacuum leak, the RPMs will be higher than normal or sporadic.

Pit Shop Auto Repair is the best auto service shop in Libertyville, IL, and we’d be happy to inspect your engine to see if you have a vacuum leak.

Transmission | Pit Shop Auto Repair - Libertyville
July 3, 2025
European cars are known for their performance, engineering, and smooth ride—but even the most finely tuned vehicle can run into problems, especially with one of its most critical systems: the transmission. At Pit Shop European, we specialize in servicing European makes and models, and we know that transmission issues can sneak up on you if...
Auto Repair | Pit Shop Auto Repair - Libertyville
July 3, 2025
When your check engine light comes on, your brakes start squeaking, or your car just doesn’t sound right, the last thing you want to deal with is an overpriced repair or pushy upsell. At Pit Shop Auto Repair in Libertyville, we believe car care should be straightforward, honest, and fairly priced—every single time. As your […]
Diesel Repair | Pit Shop Auto Repair - Libertyville
July 2, 2025
Top 5 Signs Your Diesel Engine Needs Immediate Attention Diesel engines are known for their power, durability, and longevity, but even the toughest trucks can break down if small problems go unchecked. Whether you’re hauling heavy loads or just depend on your diesel vehicle for day-to-day tasks, knowing the signs of engine trouble can save...
Diesel Truck | Pit Shop Auto Repair - Libertyville
June 4, 2025
How to Keep Your Diesel Truck Cool and Running Strong This Summer Summer is hard on vehicles—especially diesel trucks. Between the scorching heat, longer drives, and heavier loads, your engine works overtime. Without the right maintenance, it’s easy for problems like overheating, coolant leaks, or decreased performance to sneak up on you. At Pit Shop...
Vehicle on the road | Pit Shop Auto Repair - Libertyville
June 4, 2025
As temperatures rise, so do the demands on your vehicle. For owners of European luxury cars like BMW, Audi, and Mercedes-Benz, warm weather can bring out a unique set of maintenance concerns. While these vehicles are known for performance and engineering excellence, their precision systems can be more sensitive to heat-related stress than other makes....
A person is driving a car | Pit Shop Auto Repair - Libertyville
June 4, 2025
As the temperatures rise in Libertyville, so do the chances of vehicle issues if your car isn’t properly maintained. Summer heat, increased road travel, and unpredictable weather all take a toll on your vehicle. That’s why it’s important to run through a summer car maintenance checklist before hitting the road for vacations, commutes, or weekend […]
White car on the road | Pit Shop Auto Repair - Libertyville
May 7, 2025
As Illinois heads into the warmer months, many drivers start thinking about summer road trips, weekend adventures, and enjoying the open road. But rising temperatures can also mean added stress for your vehicle. Heat affects everything from your engine to your tires, which is why it’s important to give your car a little extra care […]
Car headlight | Pit Shop Auto Repair - Libertyville
May 7, 2025
Owning a European luxury vehicle isn’t just about driving—it’s about experiencing precision engineering, high performance, and exceptional comfort. Brands like BMW, Audi, Mercedes-Benz, and Porsche are built to last, but like any fine-tuned machine, they need proper care to stay at their best. At Pit Shop European, we specialize in servicing European vehicles and helping...
A/C Repair | Pit Shop Auto Repair - Libertyville
May 7, 2025
The Importance of Cooling System Checks in Diesel Engines Your diesel engine works hard—hauling heavy loads, powering work vehicles, and handling long drives in all kinds of weather. But as the temperatures rise, one system becomes more critical than ever: the cooling system. At Pit Shop Diesel Repair, we know how essential a well-maintained cooling...
Brake Repair | Pit Shop Auto Repair - Libertyville
April 4, 2025
​​Your brakes are one of the most important safety systems in your vehicle. When they’re working properly, they help you stop smoothly, avoid accidents, and stay in control on the road. But when something goes wrong, delaying brake repairs can put you—and others—in serious danger. Take a look at these five signs your car needs […]