Cadillac

Cadillac Repair Questions? Ask a Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Cadillac

How to diagnose bad purge valve symptoms?

Customer Question
How to diagnose a bad...

How to diagnose a bad vapor canister on a 2003 Cadillac CTS? What are purge valve symptoms?

My 2003 cts 3.2 engine wont start after fueling unless I go full throttle. I’ve read that almost everyone fix their problem by changing the vapor canister purge valve, but I removed mine and checked it by applying 12volts and ground. It seems like it’s working fine, it clicks and I also blew thru the valve with no power on it and its sealed. Also, sucked on it and no air passed thru until applying 12volts. Replaced vent solenoid, the one that goes inside the canister cause its only 30 bucks. Still acting the same when fueling. I have codes for o2 sensor bank 2 sensor 2 that I have not replace and just got crankshaft position sensor code recently. No issues after being able to start the car. I have a scanner and manually opened the purge valve to 100 and the car stumbled and quit running. Did the same thing with the vent valve triggered it on and the car quit. I reset the values and car ran fine as usually. Problem only happens after adding fuel.

Submitted: 2 years ago.Category: Cadillac
Show More
Show Less
Ask Your Own Cadillac Question
Answered in 24 minutes by:
8/12/2015
Cadillac Mechanic: cloe0626, Auto Mechanic replied 2 years ago
cloe0626
cloe0626, Auto Mechanic
Category: Cadillac
Satisfied Customers: 824
Experience: was a mechanic in the army for four years and have been working at a dealer ship the past five years
Verified

This situation continues, these vapors can flood the engine cylinders, resulting in an abnormal fuel mixture getting created and burned. This causes the engine to misfire and choke.

2) Failure to Clear Emission Tests

Every car on the road is required to pass the sate-sanctioned emission test, which imposes an upper-limit on the various gases and pollutants that come out through a car's exhaust. If the canister purge valve malfunctions, it may be unable to redirect the fuel vapors back into the emission system. These vapors contain harmful hydrocarbons, which will then escape through the car's exhaust, and therefore show up in the emission tests. Thus, if your car fails the emission test, its purge valve may be at fault.

3) Damaged Gaskets

A normally functioning purge valve releases fuel vapors into the charcoal canister, where they are stored until they are recycled. A bad purge may not open to allow these vapors to pass. As a result, pressure will start to build inside the system. This pressure can be so intense that it can blow out the gasket and rubber seals, causing oil to leak and get sprayed out of the emission system and onto the engine and engine compartment. If left unresolved, this will create even more severe issues.

4) Damaged Spark Plugs

A faulty purge valve may by unable to redirect the fuel vapors into the engine's cylinders for combustion. As a result, an unnecessarily rich fuel and air mixture will get combusted during each cycle of the engine. This produces extra heat, which in the long run will wear out the spark plugs. Thus, if your car's spark plugs seem to have worn out earlier than expected, most likely, the purge valve in your car is not functioning properly.

Ask Your Own Cadillac Question
Customer reply replied 2 years ago

What should I test to find my problem? I replaced the evap vent solenoid. Checked purged solenoid by applying 12 volts it opens and close. Triggered both solenoids with scanner. Engine shuts off when triggered. What should I do?

Cadillac Mechanic: cloe0626, Auto Mechanic replied 2 years ago

If it shuts of when you trigger the solenoids then I would replace the purge valve because it shouldn't shut off

Ask Your Own Cadillac Question
Customer reply replied 2 years ago

Okay. My scanner gives me the option of the purge valve and what percent I want it. I gave the purge valve 100%. That’s when the engine stumbled and then shut off. So, it should not do that? If this is my problem, I’ve looked for that purge valve everywhere literally. Where can I order it from? My car has the 3.2 engine.

Customer reply replied 2 years ago

Even though it’s for the 3.6 its compatible with my engine? Supposedly the one that's for my car comes with the lines attached to the solenoid. Just want to verify before ordering.

Cadillac Mechanic: cloe0626, Auto Mechanic replied 2 years ago

I ran a compatibly check it will work.

If you need anything else please let me know and rate my service when you get the chance.

Ask Your Own Cadillac Question
featured content

Purge valve troubleshooting

The most frequent issue with apurgevalve is when it remains open or partially open. Either issue may trigger the "Check Engine” or other error codes. A faulty purgevalve may preventthe vehicle from starting after refueling.A malfunctioning purge valve often emits unusually high exhaust which could make the vehicle fail emissions testing. When fumes build-up in the fuel lines it can cause the vehicle to backfire or stall.

Faulty purge valve symptoms

Fault code or Check Engine light

A common sign of a faulty purge valve is a fault code or check engine light that displays in the instrument panel. To determine what is causing the fault code or warning light have the car placed on a diagnostic scanner.

Difficulty starting
A problem with the purge valve can cause a vacuum leak. When there is a vacuum leak, this can cause the vehicle to have problems starting. A vacuum leak will allow excess air into the motor, which disturbs the air-fuel ratio causing performance issues.

Rough idle
A faulty purged valve may cause the engine to idle roughly. If the purge valve sticks open, it affects the idle speed and performance quality. A vacuum leak can also stem from damaged or detached purge valve hoses.

Engine Misfire
A purge valve can cause the engine to misfire. If the purged valve does not open on time, it may cause excessive fuel emissions buildup in the charcoal canister. Over time, the emissions buildup can flood the engine cylinders, resulting in an irregular fuel mixture causing the engine to misfire or stall.

Testing the purge valve 

The testing procedure may be different depending on the make and model of the vehicle. Check the specific vehicle’s manual for instructions on how to check the purge valve. Without voltage, the purged valve should be closed and open when the voltage is applied. Some service manuals recommend applying a battery connection to the terminals of the purged valve and listen for an audible click. If the click is heard the purge valve is opening correctly.

Next, test the purge valve to see if it closes properly. Connect a vacuum pump to the purge valve. If the vacuum pressure drops, the valve is not closing properly and will need replaced. If the vacuum pressure remains steady, the purge valve is closing correctly. An emissions test is another way to check for a faulty purge valve. If unusually high exhaust levels are detected, replace the purge valve or its hoses.

Knowing how to troubleshoot a purged valve can help save time and money. If the vehicle displays any of the symptoms mentioned above, you may be able to fix it on your own with a little effort.

Ask cloe0626 Your Own Question
cloe0626
cloe0626
cloe0626, Auto Mechanic
Category: Cadillac
Satisfied Customers: 824
824 Satisfied Customers
Experience: was a mechanic in the army for four years and have been working at a dealer ship the past five years

cloe0626 is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Jerry Newton

Jerry Newton

Cadillac Technician

1,569 satisfied customers

ASE Master Technician, L1, Master GM Technician. Over 20 years of bumper to bumper GM experience.

Dave Nova

Dave Nova

Cadillac Technician

1,522 satisfied customers

ASE Master Certification. GM World Class Certification

Gm Tech (Cam)

Gm Tech (Cam)

Cadillac Mechanic

1,001 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

John

John

ASE Certified Technician

941 satisfied customers

ASE CERTIFICATIONS A1-A8 & L1 / 40 YEARS AUTOMOTIVE EXPERIENCE

George H.

George H.

ASE Certified Technician

774 satisfied customers

ASE Master Tech 15+ Years

Chris (aka- Moose)

Chris (aka- Moose)

Cadillac Technician

734 satisfied customers

16 years of experience

Don - Mo Lurch

Don - Mo Lurch

Cadillac Technician

688 satisfied customers

GM, Cadillac Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

< Previous | Next >

Related Cadillac Questions
07 Cadillac CTS 2.8, both Corner brake lights not working
07 Cadillac CTS 2.8, both Corner brake lights not working but third brake light on trunk does operate correctly. Fuses not blown bulbs have been replaced and still only have one of three brake lights … read more
Shawn Few
Shawn Few
AS
64 satisfied customers
I have a 2003 Cadillac CTS that was equiped with an Analog
I have a 2003 Cadillac CTS that was equiped with an Analog phone, but was changed to digotal by a dealership. The phone stopped working and I was told by onstar that it could not be fixed. The dealers… read more
Chris (aka- Moose)
Chris (aka- Moose)
Cadillac Technician
Vocational, Technical or Trade School
734 satisfied customers
The engine of my 2006 cadillac cts was changed by an engine
the engine of my 2006 cadillac cts was changed by an engine of a 2008 cts the car worked very well for 11 months, a month later I had to try 2/3 to start the car, then it was not possible to turn it o… read more
Michael Solis
Michael Solis
259 satisfied customers
It has a lean condition and we are repairing the exhaust.
it has a lean condition and we are repairing the exhaust. getting lean code. … read more
Gunvir Singh
Gunvir Singh
1,706 satisfied customers
Cadillac CTS 4 DR, WINDOWS FUSES LOCATION. I HAVE CHECKED
i HAVE CHECKED AND DOUBLE CHECKED FUSES, BUT i AM MISSING THAT ONE FUSE … read more
Kavey
Kavey
86 satisfied customers
I have a 2006 cts, RWd. I have a 2006 cts rwd with 3.6
hi I have a 2006 cts rwd with 3.6 engine. 131,000 miles. Transmission was going out so I had it replaced with a used tranny from an 07 with 46,000 miles. The transmission seems to be working fine in all ranges, shifting ok but I still have a random at different times while driving a sound that seems to be coming from the transmission area like a short buzzing or humming noise. Usually happens while steady rpms, not under acceleration. It started making this same random noise in the previous transmission when it started to go out. Finally it quit shifting into gears and in overdrive the previous trans would run at 3000 rpms at 65. This new used trans seems to be making the same just random "buzzing" or humming noise. It doesn't stay for very long. Just comes and goes. Am I looking in the right place or is it just coincidence that this is another issue that started when my original trans failed. Also, there is no transmission dipstick or a way to fluid replace in these units. Is this trans maintenance free? I can't believe that an automatic trans would be maintenance free. … read more
ggrote1
ggrote1
Vocational, Technical or Trade Scho
13 satisfied customers
My Cadillac CTS 2006 it will start but it will not stay
My Cadillac CTS 2006 it will start but it will not stay running it will only stay started for like a half a second what is that problem caused from… read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
I don't have reverse. 03 cts. No I just got it out of the
No not from my cooling system, but from my transmission lines… read more
Kavey
Kavey
86 satisfied customers
I have a 2004 cadillac cts 3.6l and it will not start. i get
i have a 2004 cadillac cts 3.6l and it will not start. i get a code of lost communication with eco/pcm a . when i turn over the key a clicking noise comes from a relay in the back passenger side bank … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
I have a 2005 cadillac cts 3.6 l engine. Car shuts off while
I have a 2005 cadillac cts 3.6 l engine. Car shuts off while driving on the road. It only does it after i reach 5 gear. Once in 5 th gear i could be crusing and all is fine but when i slow down enough… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Drivers door will not latch. 2012 CTS coupe. Releasing the
Drivers door will not latch JA: What is the model/year of your Cadillac? Customer: 2012 CTS coupe JA: Are you fixing your CTS yourself? What have you tried so far? Customer: releasing the door lock sw… read more
ggrote1
ggrote1
Vocational, Technical or Trade Scho
13 satisfied customers
2010 CTS Performance started making a low hum that is
2010 CTS Performance started making a low hum that is speed-specific. Seems like engine is working harder with higher rpms at speeds over 50 mph. Fuel consumption up a little, too. … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
I HAVE A CADILLAC CTS 2005 3.6L WITH THE FOLLOWING ENGINE
I HAVE A CADILLAC CTS 2005 3.6L WITH THE FOLLOWING ENGINE CODES … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Engine light came on on my 2008 Cadillac CTS 3.6. Went to
Engine light came on on my 2008 Cadillac CTS 3.6. Went to Autozone, used their scanner. Actually used two different scanners. Code came up the same, both times P2601, which their computer identified a… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Cadillac CTS 2005. I have a no start issue with my cts. I'm
Cadillac CTS 2005. I have a no start issue with my cts. I'm thinking it is the ecu and not the starter. Battery is fine. For my next step in the trouble-shoot, I am about to jump the starter relay by … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
2004 CTS put my key in ignition engine will not turn over
2004 CTS put my key in ignition engine will not turn over and it locks doors when you turn key but key will not come out of ignition what can I do? … read more
Chris (aka- Moose)
Chris (aka- Moose)
Cadillac Technician
Vocational, Technical or Trade School
734 satisfied customers
2008 CTS. engine light comes on, then service TCS. engine
2008 CTS. engine light comes on, then service TCS. engine power is reduced. Will not allow the cruise control to work. limits carburetor and there has been times when it will keep the car from getting… read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
45 satisfied customers
Cadillac CTS: thermostat but the check engine light keeps
Cadillac CTS: thermostat but the check engine light keeps coming … read more
Gunvir Singh
Gunvir Singh
1,706 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x