Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

2002 trailblazer check engine is coming on. Flashing

Customer Question
2002 trailblazer check engine...

2002 trailblazer check engine is coming on. Flashing sometimes. Rough idling, especially in drive,

Mechanic's Assistant: Is the rough idle intermittent or consistent?

So far it's been intermittent but becoming more often.

Mechanic's Assistant: Are you fixing your Trailblazer yourself? What have you tried so far?

Haven't done anything yet, thought about new plugs. It has 198,000 on the odom.

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

Is it ok to drive.

Submitted: 2 months ago.Category: Chevy
Show More
Show Less
Ask Your Own Chevy Question
Answered in 5 minutes by:
5/29/2018
Chevy Mechanic: Ron Z., - Chevy Tech - replied 2 months ago
Ron Z.
Ron Z., - Chevy Tech -
Category: Chevy
Satisfied Customers: 20,070
Experience: 18+yrs experience. State Inspector and Chevy Diagnostics
Verified

Hi! Welcome to JustAnswer. Thanks for coming! I'm Ron and I'll be working with you on your question today. Please give me a moment to review your question and type out my reply. Sit tight one minute... I'll be right back!

Ask Your Own Chevy Question
Chevy Mechanic: Ron Z., - Chevy Tech - replied 2 months ago

Thanks for holding!

From what you are describing here, it sounds like this is going to be a case of a cylinder misfire. There are a few different things that can cause a cylinder misfire. This can be worn spark plugs, a faulty ignition coil, a faulty fuel injector, low cylinder compression, an intake air leak, etc. Best place to start here is with the spark plugs. Remove a plug and inspect the body for any cracks and the diode for excessive wear. If there are any doubts, replace all the spark plugs. If the spark plugs look ok, or new ones do not solve the issue, you should have the diagnostic trouble codes (aka "p-codes") scanned from the on-board computer. You can have these p-codes read FREE (except in California) at any local "big chain" part store (ie. AutoZone, O'Reilly's, Advanced, etc). These p-codes will more accurately point to the cylinder(s) that are having the misfire. From there, the ignition coil(s) and injector(s) for those cylinder will need to be tested. If these check ok, then ultimately, a cylinder compression test will need to be done. Please be kind enough to leave a rating for our Q&A using the 'stars' at the top of the page when I have answered all your questions. A 5-star rating is very much appreciated! Rating my answer does not cost you extra.

Ask Your Own Chevy Question
Chevy Mechanic: Ron Z., - Chevy Tech - replied 2 months ago

Were there any other questions I could help you with today?

Ask Your Own Chevy Question
Chevy Mechanic: Ron Z., - Chevy Tech - replied 2 months ago

Were there any other questions I could help you with today?

Ask Your Own Chevy Question
Chevy Mechanic: Ron Z., - Chevy Tech - replied 2 months ago

HI! I noticed this Q&A was still open, so I wanted to check in and see if there was anything else I could do for you on this? Any other questions you had?

Ask Your Own Chevy Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a chevy mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Ron Z. Your Own Question
Ron Z.
Ron Z.
Ron Z., - Chevy Tech -
Category: Chevy
Satisfied Customers: 20,070
20,070 Satisfied Customers
Experience: 18+yrs experience. State Inspector and Chevy Diagnostics

Ron Z. 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:

I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money.

Todd LRochester NY

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

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Chevy Technician

15,756 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,642 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,884 satisfied customers

Have owned a repair shop for 25 yrs.

Dave Nova

Dave Nova

Chevrolet Technician

7,092 satisfied customers

ASE Master Certification. GM World Class Certification

John

John

Master A.S.E Automotive technician

4,071 satisfied customers

A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician

Don - Mo Lurch

Don - Mo Lurch

Auto Mech / Electronics

2,953 satisfied customers

Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

Ron Z.

Ron Z.

- Chevy Tech -

20,070 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
Rough idle when it's put into drive at cold start, once it
Rough idle when it's put into drive at cold start, once it warms up to operating temp smooth out … read more
John Vieira
John Vieira
Heavy Duty Diesel Mechanic
63 satisfied customers
Yesterday my 2002 trailblazer ls with 137245 miles started
Yesterday my 2002 trailblazer ls with 137245 miles started running rough. I scanned and received code P0301. I know this is a misfire on #1. However, the "service engine soon light" what's flashing. H… read more
Ron Z.
Ron Z.
- Chevy Tech -
Vocational, Technical or Trade Scho
20,070 satisfied customers
What would be the estimated cost to replace the onboard
What would be the estimated cost to replace the onboard computer for my 2002 trailblazer. The engine sometimes stalls out when engine is cold. Been told issue may be the computer not sending correct m… read more
Ron Z.
Ron Z.
- Chevy Tech -
Vocational, Technical or Trade Scho
20,070 satisfied customers
2006 Trailblazer with flashing check engine light. OBD codes
2006 Trailblazer with flashing check engine light. OBD codes P0300, P0449, and B1000. The engine control unit, evap canister, coils, spark plugs have all been replaced. Between 2 dealerships, I've spe… read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
I have an 02 Chevy TB (recently changed oil) in the past
I have an 02 Chevy TB (recently changed oil) in the past year it's been in the shop for Bank 2,3, 4, 5 Misfire. Shop fixed it and it was running fine until yesterday. Service Engine light came on and … read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
Rough idle. consistent, actually its a GMC 4x4 zr2 2002
I changed dist. rotor camsensor dist. cover no change … read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
I have a 2011 chevy malibu 3.6 it is rough idle and stops
I have a 2011 chevy malibu 3.6 it is rough idle and stops when idle up but is throwing cylinder 4 misfire in a changed coil packs and plugs around and checked vacuum leaks only thing l haven't done is… read more
GM Bob
GM Bob
Automobile Technician
High School or GED
1,061 satisfied customers
It's an 08 the idles rough but when it warms up it's fine,
It's an 08 the idles rough but when it warms up it's fine … read more
Jared D
Jared D
Shop Supervisor
Bachelor\u0027s
3 satisfied customers
Man it shuts off hard and it has died on me a couple times
Man it shuts off hard and it has died on me a couple times here in the past couple weeks then it died and check engine light came on read code P0606 and i cleared it started fine and hasn't happened a… read more
Tim&#039;s Auto Repair
Tim's Auto Repair
mechanic
High School or GED
8,884 satisfied customers
I own a Chevy 2002 2WD 4.2L 6 cylinder Trailblazer. On my
I own a Chevy 2002 2WD 4.2L 6 cylinder Trailblazer. On my way to work this morning, all of a sudden my engine starting running rough. It felt like one of the cylinders was not firing. Acceleration is … read more
roy
roy
Associate Degree
3 satisfied customers
chevy trailblazer: We have a 2005 chevy trailblazer that is
We have a 2005 chevy trailblazer that is idling rough. my husband has replaced all spark plugs put in a new ignition coil and took the throttle body off and thoroughly cleaned it yet the truck is stil… read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
Chevrolet Trailblazer LS: hello 2003 trailblazer 6 cyl 158000
hello 2003 trailblazer 6 cyl 158000 miles lost power yesterday p300 code rough idle light blinking… read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
2007 trailblazer: The engine light comes..dump..light goes..comes back
i have a 2007 trailblazer. The engine light comes on a lot. I dump some gas treatment in it, like slick 50 and the light goes out for a couple of days but then comes back on. It runs fine but idles ro… read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
2002 trailblazer: my transmission fluid..leaking..my driveway
I have a 2002 trailblazer and recently checked my transmission fluid and found it to be about a pint and half low but I haven't noticed any leaking on my driveway. Where could this fluid be going?… read more
Tim&#039;s Auto Repair
Tim's Auto Repair
mechanic
High School or GED
8,884 satisfied customers
2002 olds bravada: tune..a really rough idle, rpms do not fluctuate
i have 2002 olds bravada with 132000 miles. just had tune up and induction service. before and alot now, i have a really rough idle, rpms do not fluctuate, does this hot or cold. my mechanic swears it… read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,642 satisfied customers
1996 Chevrolet Lumina: rough idle..accelerate..it will smooth
Having intermittent problem with rough idle on 1996 Chevrolet Lumina with 3/1L v-6. When car is cool is starts fine but when is hot sometimes the idle is very rough and will not accelerate at all. Som… read more
rodcuda
rodcuda
Auto repair pro, 30 years experience
Associate Degree
74 satisfied customers
2002 trailblazer: the spark plugs..idles rough..check engine light
i changed the spark plugs in my 2002 trailblazer set recommended gap of 043 for iridium plugs.it idles rough and after a couple of minutes check engine light flashes on. help!!!! what ca i do to corre… read more
Ivan
Ivan
Automotive Instructor
Vocational, Technical or Trade Scho
3,337 satisfied customers
2001 chevy blazer: check engine light..about ten minutes..idles rough
2001 chevy blazer check engine light flashed for about ten minutes, then cleared up. vehicle idles rough, feels like stuttering.… read more
GMTechBernard
GMTechBernard
Owner / Technician
High School or GED
1,644 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