It is possible to bypass purge valves yourself. But it would help if you did it in the right way. If you don’t, your vehicle may malfunction due to bad practice. So, knowing how to Bypass Purge Valves and more facts about purge valves is good.
Table of Contents
- What Causes A Purge Valve To Go Bad?
- What Happens If You Bypass The Purge Valve?
- How To Bypass The Purge Valve?
- How To Test Purge Valve With a Multimeter?
- Purge Valve Symptoms
- Driving With Bad Purge Valve
What Causes A Purge Valve To Go Bad?
Vehicles have a system for controlling how much gasoline vapour goes into the air. The purge control valve is a part of this system that controls pollution. However, the solenoid’s failure depends on other emissions system factors.
Emissions System Functions
After fuel goes into the gas tank, gasoline vapours travel to a storage canister inside the car. The solenoid on the purge control valve lets these vapours out of the canister and into the throttle body and manifold of the vehicle. Most of the time, the solenoid valve is closed to keep the steam inside the canister.
Causal Failure Factors
A broken valve could cause a leak in the emissions system. The purge control valve opens and closes in response to the vapour vacuum inside the canister. If the canister or supply lines are blocked or have holes, the solenoid won’t work, and the purge control valve will stay closed. Additionally, the electrical component of the solenoid may malfunction, leaving the valve closed.
What Happens If You Bypass The Purge Valve?
You can bypass the purge valve yourself. But it has to be done right, or you could end up with problems like an engine emission failure, a Check Engine Light (CEL) on the dashboard, a collapsed fuel tank, an engine misfire, less fuel economy, a jerky idle, vehicle starting issues, flooding of the charcoal canister, and a fuel smell.
Getting a new purge solenoid is better than bypassing the purge valve. These problems could differ depending on how the EVAP fuel system’s circuit and controllers are made.
How To Bypass The Purge Valve?
You can follow this guide if you wish to bypass the purge valve.
Step 1 – Remove The Bad Charcoal Canister
It has two lines at the top and one line at the bottom.
With the ones on top, you squeeze and twist them with the pliers. If you spray some WD-40 on them beforehand, they will quickly come out.
The engine vacuum line will loosen after some twisting and pulling, and lubricating.
Step 2 – Bypass the purge valve
Next, to remove the EVAP solenoid, you must unplug it from a line on its edge and a nut at the bottom. Just pull the plug on the side, and it will move out of the way.
You’ll need a ten-millimetre socket and an open-ended wrench to remove the nuts.
Two engine vacuum lines are attached to the purge solenoid:
One travels above the vapour storage, which is already unplugged, and the other loops around beneath the engine air intake manifold.
Plug off the end of the second engine vacuum line. Then, use the assortment kit to find a matching cap on the vacuum ports.
Step 3 – Loop the other hoses to avoid vacuum leaks
To prevent the engine base from becoming overly filled with fuel fumes and odour, you must loop the feed and the return lines for the fuel vapour.
There is a piece of rubber pipe on the engine vacuum line. Turn that rubber line around and plug it into both ends of the ports and the bar.
How To Test Purge Valve With a Multimeter?
Follow this step-by-step guide to test the purge valve with a multimeter.
Step 1 – Locating the Purge Valve
Make sure to turn off your engine for 15 to 30 minutes before you start the test. Then, find the purge valves behind the silencer and on top of it. This will help you not only do this procedure right but also stop any leaks that might happen along the way if one does occur during testing.
Step 2 – Rearranging the Cables
You might notice that a two-pin harness connects purging valves. However, it is best not to join this directly to your multimeter’s adapter cables or test leads, which usually come with the multimeter. Instead, you should disconnect the old line and connect its terminals to the suitable probes on an output device such as a digital voltmeter. It would help you to keep an eye on voltage readings as testing is done.
Step 3 – Testing or Checking
It’s time to measure the resistance. You need a new valve if the reading is less than 22 ohms or more than 30. So, having an extra valve standby would be helpful on this kind of occasion. There is nothing wrong with the valve if it is between 22 ohms and 30 ohms.
Purge Valve Symptoms
Here are the top symptoms of a bad purge valve.
The engine control system keeps track of and controls the number of vapours your car’s emissions systems release. If this system has a problem, it shows an error code such as P0446. In the worst case, the purge solenoid could fail, which could cause much more significant issues, like damage to the catalytic converter.
An issue with the engine
If a purge valve breaks, it can cause a lot of trouble. Starting your car will be more challenging because the engine will try harder in response.
Lower Gas Mileage
Gas mileage will inevitably drop if the EVAP system isn’t functioning correctly.
Bad results on the emissions test
The EVAP system is responsible for sending the fuel vapours back into the engine. If it doesn’t work, you won’t pass the emissions test.
Pressure can increase if the purge valve isn’t working correctly. This vital force could blow out rubber seals and gaskets and cause oil to leak, which could get onto essential engine parts and cause severe damage.
Purge Valve Stuck Closed Symptoms
The symptoms can be different when the valve is stuck closed or open. But the engine light warning is always standard for both occasions.
A vacuum hose is part of the purging system for the engine. When the purge valve is stuck open, air leaks out so that all of the fuel can be sucked out before the valve closes completely.
The worst part about a stuck open purge valve is that you might not notice there is a problem for weeks. It usually doesn’t appear as a code until the system has been damaged by carbon buildup in its spring pressure Relief Valve and butterfly diaphragm.
Driving With Bad Purge Valve
Driving with a bad purge valve is not a good idea. A bad purge valve can damage the engine, the EVAP system, and other parts of the car. Additionally, it may cause more emissions or burn fuel than is necessary.
Can a faulty purge valve cause a misfire?
It can definitely cause a misfire since the purge valve in a car’s EVAP system is what brings fuel vapours back into the car’s combustion chamber.
Is there a way to test a purge valve?
Yes! You can do a multimeter test. Set your multimeter to Ohms, put the probes on the power terminals of the purge valve, and check for resistance between the terminals. If the reading is below 22 Ohms or above 30 Ohms, the purge valve is damaged and needs to be replaced.