GMC

GMC troubleshooting questions? Ask a mechanic for answers

Ask an Expert,
Get an Answer ASAP!

06 envoy 6 cilynders P0300 car running nice but engine light…

Customer Question
06 envoy 6 cilynders...
06 envoy 6 cilynders P0300 car running nice but engine light is flashing spark plugs check, coils, mad sensor, no lean codes, just theP0300 when I go to more rpm the light stop flashing is just when is in iddle runs very good but I can't find the issue
Submitted: 11 months ago.Category: GMC
Show More
Show Less
Ask Your Own GMC Question
Answered in 4 minutes by:
8/2/2017
GMC Mechanic: Gunvir Singh,
 replied 11 months ago
Gunvir Singh
Category: GMC
Satisfied Customers: 2,013
Experience: Master Tech at Kennesaw Auto Tech
Verified

Hello, let me review your request. Please stand by,

Ask Your Own GMC Question
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

Roughly how many miles do you have on the vehicle? has the vehicle overheated recently?

Ask Your Own GMC Question
Customer reply replied 11 months ago
I changed the engine with 89 k on it do you think is a blow head gasket?
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

Not the head gasket but these engines are notorious for leaking valves.

Ask Your Own GMC Question
Customer reply replied 11 months ago
Sometimes the scanner shows the misfire in cilynders 1 and I reset the light and change to p0300
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

On this vehicle the vehicle has to be driven a while before it pics up the exact cylinder misfire. Since it shows #1 cylinder misfire i will start by checking that first. Since you have already replaced the plugs and coils. Only thing left is the fuel injector and interal valve leak. A cylinder leakdown test will need to be performed to check if it has internal valve leak.

Ask Your Own GMC Question
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

Do you have any other questions?

Ask Your Own GMC Question
Customer reply replied 11 months ago
When is not in iddle runs fine do you think is going to get worse?
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

Eventually it will, just a matter of time.

Ask Your Own GMC Question
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

Do you have any other questions?

Ask Your Own GMC Question
GMC Mechanic: Gunvir Singh,
 replied 11 months ago

Please read this:

Understand it's not one answer and done. We can communicate back and forth many times.

1. I am an independent auto mechanic and do not work at or for Just Answer.

2. When you're pleased or happy with my assistance or efforts to help you, at the top of the screen please rate me .

3. I only get credit for my work from your question value deposit when you rate me on this screen. Rating does not close the post and you're more than welcome to follow up.

Thanks for using Just Answer

Ask Your Own GMC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a gmc mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Gunvir Singh Your Own Question
Gunvir Singh
Gunvir Singh
Gunvir Singh
Category: GMC
Satisfied Customers: 2,013
2,013 Satisfied Customers
Experience: Master Tech at Kennesaw Auto Tech

Gunvir Singh 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:

Gm Tech (Cam)

Gm Tech (Cam)

GMC Mechanic

1,796 satisfied customers

GM Grand Master Technician 2007. 14 year experience.

Gary

Gary

ASE Certified Technician

1,588 satisfied customers

GCM master tech over 25 years

Dave Nova

Dave Nova

GMC Technician

929 satisfied customers

ASE Master Certification. GM World Class Certification

Chris (aka-Moose)

Chris (aka-Moose)

GMC Technician

626 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- GMC Tech -

279 satisfied customers

18+yrs experience. State Inspector & GMC Diagnostics/Repair

JFN1

JFN1

ASE Certified Technician

270 satisfied customers

GM Master Technician

George H.

George H.

ASE MasterTechnician

228 satisfied customers

15+ Years ASE Master Technician with Level 1 Certification

< Previous | Next >

Related GMC Questions
My 2012 GMC Acadia is throwing codes. The primary is p0300.
My 2012 GMC Acadia is throwing codes. The primary is p0300. Since the codes have been reset, no check engine light, but it won't stay running. … read more
roy
roy
Associate Degree
3 satisfied customers
MY DAUGHTERS CAR 2005 ENVOY 6 CYL. CHECK ENG. LIGHT ON CYL.
MY DAUGHTERS CAR 2005 ENVOY 6 CYL. CHECK ENG. LIGHT ON CYL. 3 NOT FIREING REPLACED ALL PLUGS NOW A RUNNING LEAN CODE P0300 COMES UP . TRIED CLEANING IAC STILL LEAN . … read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,796 satisfied customers
Getting a p0300 code. P0300, yes we did reset. 04 envoy
suv was running fine, and then it suddenly stald, when turning into drive way. restarted and it started to run ruff! check engine light started flashing, while driving!… read more
Expert
Expert
30 satisfied customers
I have an envoy 06 it has a P0300 it runs but very bad.
Hi I have an envoy 06 it has a P0300 it runs but very bad. There is a lot smoke getting out of the exhaust (kind of gray) I hear a little knock I already changed the spark plugs and the coils.… read more
Amedee
Amedee
Automotive Consultant
Vocational, Technical or Trade Scho
19,169 satisfied customers
I am having an issue with my 07 Escalade esv. I'm throwing
I am having an issue with my 07 Escalade esv. I'm throwing both C0561 and P0300. Has brand new plugs and wires.… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
Pulling codes P0300, C0035, C0055. Be 0090, U1016, B2610,
Pulling codes P0300, C0035, C0055. Be 0090, U1016, B2610, B1420, B2961, U1071Transmission shifting hard and acting funny. Brand-new Jasper transmission. 2006 GMC savanna 3500 4.8 L gas… read more
Ryan Schott
Ryan Schott
76 satisfied customers
The senser said it was coil and number 6 plug. I replaced them
the senser said it was coil and number 6 plug. I replaced them engine light went for a couple of days,now it has come back on. the tester says same thing number 6 plug and coil. any answer is apprecia… read more
Ron Z.
Ron Z.
- GMC Tech -
Vocational, Technical or Trade Scho
279 satisfied customers
Having a problem with my 2009 GMC Acadia. The other day it
Hi, This is Keith and having a problem with my 2009 GMC Acadia. The other day it started running real rough and the CEL activated and at some point it would flash and go back steady. Smelled of raw fu… read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,796 satisfied customers
I just bought a 2002 envoy sle. It has 121000 miles. It had
I just bought a 2002 envoy sle. It has 121000 miles. It had a miss in it. So I replaced the fuel filter,rear 02 sensor,crankshaft and camshaft sensor and spark plugs. The plugs I used were ac delco. N… read more
AZTechBrian
AZTechBrian
ASE Certified Technician & Shop Owner
Vocational, Technical or Trade School
732 satisfied customers
I have a 2006 gmc sierra with a 6.0 engine, I have been
I have a 2006 gmc sierra with a 6.0 engine, I have been getting a p0300 code for awhile now. I changed plugs and wires, fuel pump and maf sensor to no avail, this is a work truck and travels mainly on… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
2003 Envoy inline 6 idle rough when stopped no check engine
2003 Envoy inline 6 idle rough when stopped no check engine light. After it runs for a while its alright.… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC Envoy SLT: 2007 GMC Envoy 4.2L drove fine last night stopped
2007 GMC Envoy 4.2L drove fine last night stopped and restarted. Noticed it felt like running on 3 cylinders and the CEL came on flashing. Wouldn't hardly run and checked it has a P0300 code today. I … read more
BOBBYSS
BOBBYSS
Automotive Repair/Damage Investigator
Associate Degree
14,541 satisfied customers
GMC Yukon 4x4: I have a 98 Yukon 4wd... It throws a p0300
I have a '98 Yukon 4wd... It throws a p0300 at speed between 2200 RPM and 3000 rpm or so. You can feel it 'chug' or 'surge'. Car has 112k miles. Mechanics have replaced the fuel spider/injectors with … read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC Envoy XL: GMC envoy 5.8L V8 check engine light came on
GMC envoy 5.8L V8 check engine light came on and when I am idling at a stop light it sounds like it is going to quit. I have a innova code reader and the codes that it says are 4 codes: P0171-generic-… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GM Envoy: I have an 02 envoy with 290,000 miles. The SEL light
I have an 02 envoy with 290,000 miles. The SEL light on an blinking. I went to AutoZone who said I have a P0300 code. It is running rough and chugs but maintains 600 RPM at idle in drive or parked. It… read more
Jerry
Jerry
Service consultant
Vocational, Technical or Trade Scho
13,107 satisfied customers
I have an 04 Envoy,6 cylinder.Getting a code P0300.I changed
I have an '04 Envoy,6 cylinder.Getting a code P0300.I changed the plugs with AC Delco,and replaced all boots with included springs.Still getting code! The original code was P0306,which prompted me to … read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,796 satisfied customers
I have a 1998 chevy camaro 3.6 engin service engin light
i have a 1998 chevy camaro 3.6 engin service engin light stays on skipes bad at times most of the time it,s ok , when it skips the service engin light blinks on and off put new gas cap and coil as aut… read more
Hal
Hal
owner/service tech
Vocational, Technical or Trade Scho
924 satisfied customers
GMC Sierra: service soon light is flashing. engine running
service soon light is flashing. engine running rough idle. just changed o2 sensor driver side. 2005 sierra 2500 hd with 6L gasoline.… read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,796 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