Updated at: 28-07-2022 - By: Lucas

Combustion engines have the drawback of pressure buildup within its internal components. Vacuum hoses for the EGR system release pressure and allow the combustion process to properly discharge exhaust.

Every component, including EGR vacuum hoses, is exposed to debris, dirt, heat, muck, and other conditions that lead to failure or wear.

Mechanics can suffer mechanical failures, from a complete system shutdown to engine misfires, if they leak or get disconnected when they break.

Every time you replace your car’s oil or have it tuned up, have the EGR vacuum hoses inspected. This is recommended by most auto manufacturers and mechanics.

The engine’s performance and stability are negatively impacted by the removal of an EGR vacuum hose. A leak might cause the EGR valve to not open, resulting in an increase in hazardous emissions and engine overheating.

Here are some of the issues that arise when the EGR vacuum hose is disconnected:

  • Hesitation
  • Low power
  • Poor brakes performance (on power brakes)
  • Stalling
  • Stumbling
  • Poor acceleration
  • Low idle or high idle depending on the model of the vehicle
  • Backfiring
  • Poor fuel economy
  • Hard starting
  • Misfiring (sometimes random)
  • Rough idlep

The above-mentioned symptoms may be caused by a leaky ERG vacuum hose, although this is not necessarily the case. A defective ERG valve or ignition timing issues could also be to blame for some of the symptoms.

What can happen to an engine if you drive with a disconnected vacuum hose?

EGR Valve Vacuum Leak-2

A leak in the EGR vacuum hose system is the most typical problem. As a result, your vehicle’s performance will suffer dramatically. In addition, if the vacuum hose is broken, other sections of the car will not function properly.

As a result, the diesel particulate filter (DPF) will become clogged more quickly than normal, resulting in an increase in emissions.

Here are the dangers, symptoms, and indicators to watch out for if you’re driving a car with an EGR vacuum line leak:

Vacuum lines are a common source of EGR vacuum hose system leaks. As the rubber in the vacuum lines deteriorates, it may fall off the system as a whole. If they fracture or leak, you should have a mechanic replace them.

Leakage in the system can be detected by listening for a distinct sound coming from the vehicle engine area while it is driving. Problems with the accelerator or an increased idling speed are also indicators. If you notice any of these symptoms, either alone or in combination, you should have the vacuum system fixed by a mechanic.

The Check Engine Light is another common symptom of leaking in the EGR vacuum hose system. Your car’s EGR should be inspected if the Check Engine Light comes on. If the check engine light comes on for no apparent reason, it is prudent to have the vehicle inspected.

The EGR vacuum leakage is a key cause of low fuel efficiency and power loss in the car. If you don’t fill up as often, your car will have trouble accelerating correctly and you’ll have to keep refilling the tank.

A qualified mechanic is required to repair an EGR vacuum leak. There are a lot of components in the EGR vacuum hose system, so it may take some time to pinpoint the exact location of the leak. Things’s not that simple to fix it on your own.

A detached EGR vacuum pipe can cause the engine to lose power, thus you should not drive it. When driving down a hill and the condition gets worse, this is quite dangerous. The EGR vacuum pump should be checked if you notice any of the following symptoms:

Should an EGR valve hold vacuum?

EGR Valve Vacuum Leak-3

Primary settings for the EGR valve are two-fold.

open and closed The position might also be anywhere between the two. When the engine is being started, it is shut off.

Only a little amount of power and oxygen are required when the vehicle is at a standstill or at moderate speed. As a result, the ERG valve progressively opens.

When not in use, it can have a 90% opening rate. As a result, as the vehicle accelerates to its full potential, the valve opens to let more oxygen into the cylinder.

The EGR control valve opens when the engine is under load because of the increased backpressure.

At 2000 RPM when creating backpressure, you should apply a vacuum to the valve to evaluate the EGR valve’s performance under positive backpressure conditions.


A detached vacuum hose in the EGR system can be easily detected if you keep an eye on your vehicle regularly.

As soon as you see any of these warning indicators, you should have the automobile checked out by a skilled mechanic because driving a vehicle with a disconnected EGR vacuum is extremely dangerous.