Car

Ask a Mechanic Online and Get Answers to Your Car Questions

Ask an Expert,
Get an Answer ASAP!

Car
This answer was rated:

2000 gmc sierra 2500 hd: it runs fine on flat roads..random misfire

2000 gmc sierra 2500 hd...
2000 gmc sierra 2500 hd struggles when going uphill. it runs fine on flat roads. i was told the code was just a random misfire. changed coil packs, spark plugs and wires
Show More
Show Less
Ask Your Own Car Question
Answered in 5 minutes by:
10/1/2010
danny
danny, Mechanic
Category: Car
Satisfied Customers: 5,064
Experience: Mechanic at school corp bus garage! Experience in fleet diesel and regular automotive.
Verified
Chat Conversation Started
danny :

My Answer is based on clues, symptoms and info in your question. Please include everything. Thanks

danny :

Can I have your code?

JACUSTOMER-5ynwj0f6- :

honestly i cant find the paper he wrote it on but im pretty sure it was pc 300

JACUSTOMER-5ynwj0f6- :

hello

danny :

just let me know when you get back online.

JACUSTOMER-5ynwj0f6- :

let you know what

danny :

ok

danny :

thats a misfire

danny :

random like they said

danny :

It can go deeper

danny :

Let me get you testing.

JACUSTOMER-5ynwj0f6- :

so what do you recommend

danny :

be right back with info

danny :

what size eavengine do you h

danny :

have

JACUSTOMER-5ynwj0f6- :

cool

JACUSTOMER-5ynwj0f6- :

6.0

danny :
























Subject: 97-05 Vehicles with 4.8 5.3 5.7 and 6.0 Gen III V8 Engines and Misfires on One Bank - kw CEL diagnostics driveability DTC P0171 P0172 P0174 P0175 P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 #PIP3056 - (07/12/2004)

Models: (00-05 Cadillac Escalade - C6 and K6) and (02-05 Chevrolet Avalanche - C1, C2 K1 and K2) and (99-05 Chevrolet Silverado - C1, C2 K1 and K2) and (00-05 Chevrolet Suburban - C1, C2, K1 and K2) and (00-05 Chevrolet Tahoe - C1 and K1) and (99-05 GMC Sierra C1, C2 K1 and K2) and (00-05 GMC Yukon - C1, C2, K1 and K2) and (03-05 Chevrolet Express G1, G2, G3, H1, H2 ) and (03-05 GMC Savana G1, G2, G3, H1, H2 ) and (04-05 Buick Rainier S1, T1 ) and (03-05 Chevrolet Trail Blazer EXT S1, T1 ) and (03-05 GMC Envoy XL XUV S1, T1 ) and (03-05 Hummer H2) and (04-05 Cadillac CTS-V DB) and (98-02 Chevrolet Camaro FB) and (97-04 Chevrolet Corvette YB) and (98-02 Pontiac Firebird FB) and (04-05 Pontiac GTO VB)

The following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:
Check Engine Light with a P0300 due to 2 - 4 cylinders misfiring on the same bank of the engine. DTCs P0171, P0172, P0174 or P0175 may also set for the misfiring bank.

Recommendation/Instructions:
If the published misfire diagnostic does not isolate the cause, perform the following suggestions as necessary:



  • Perform a fuel injector balance test for all 8 cylinders. If a fuel injector concern exists, it is possible to misfuel an entire bank of the engine, causing multiple cylinders on the same bank to misfire even though the root cause is a single fuel injector.

  • Inspect O2 sensor connections on the misfiring bank for corrosion or water intrusion. If water intrusion is found on the right bank, it may be due to the AC Evaporator Condensation dripping onto the O2 sensor harness. If this condition is found, reposition and shield the harness to prevent a repeat concern and repair the connections.

  • Check for excessive exhaust backpressure using the restricted exhaust diagnosis.

  • Swap the Position 1 O2 sensors side to side to see if the misfires move to the other bank of the engine. If so, replace the O2 sensor.


Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

NOTE: GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition.



JACUSTOMER-5ynwj0f6- :

thank you very much!

danny :

click here for testing also.

danny :

click here. I normally dont show sevice bulletins but I want you to have all the possiblitities as 300 is trickey













Ask Your Own Car Question
Thanks
danny
danny, Mechanic
Category: Car
Satisfied Customers: 5,064
Experience: Mechanic at school corp bus garage! Experience in fleet diesel and regular automotive.
Verified
danny and 87 other Car Specialists are ready to help you
Ask your own question now
Ask danny Your Own Question
danny
danny
danny, Mechanic
Category: Car
Satisfied Customers: 5,064
5,064 Satisfied Customers
Experience: Mechanic at school corp bus garage! Experience in fleet diesel and regular automotive.

danny 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 would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

The nearest Volvo dealer is 160 miles away. Best $15 bucks I have spent in a long time!

Paul MCorpus Christi, TX

< Previous | Next >

Meet the Experts:

Chris (aka-Moose)

Chris (aka-Moose)

Technician

1,243 satisfied customers

16 years of experience

Ted G.

Ted G.

ASE Certified Technician

1,724 satisfied customers

20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness

George H.

George H.

ASE Certified Technician

1,537 satisfied customers

ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist

GM Tech (Cam)

GM Tech (Cam)

Auto Service Tech

669 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Amedee

Amedee

Former ASE Master Tech

2,520 satisfied customers

ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector

Jerry

Jerry

Master Mechanic

2,181 satisfied customers

ASE master, 30+ years. All makes and models. Trouble shooter, shop forman, service manager

Richard

Richard

ASE Certified Technician

1,000 satisfied customers

12 years Ford Lincoln/Mercury Jaguar dealership as a technician and shop foreman reparing all makes

< Previous | Next >

Related Car Questions
Glitter in the upper fuel filter. runs well but worried.
glitter in the upper fuel filter. runs well but worried … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
Working on a 2008 Z06, that needs new front suspension after
Working on a 2008 Z06, that needs new front suspension after a collision. can anybody provide me a front suspension exploded view with the correct torque specs? and is there a specific procedure to at… read more
Chris (aka-Moose)
Chris (aka-Moose)
Technician
Vocational, Technical or Trade School
1,243 satisfied customers
Had to jump it off for 2days and today it didn't want to
Had to jump it off for 2days and today it didn't want to shut off. When it finally did shut off the dash light stayed on. … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
My husband's key fob is not working. He knows how to get the
My husband's key fob is not working. He knows how to get the physical key out of the fob, but we don't know where put it in order to unlock and then start the car since it's all keyless entry. It's a … read more
jim
jim
Vocational, Technical or Trade Scho
702 satisfied customers
I have a 2010 buick lacrosse with 2.4 4 cylinder engine i
i have a 2010 buick lacrosse with 2.4 4 cylinder engine i keep getting a reduced engine power message. if i turn the car off and wait for a couple of minutes it goes away for about 10 minutes then com… read more
vwtech0405
vwtech0405
VW Technician
Associate Degree
9,666 satisfied customers
A light tapping sound when in park goes away when in gear. A
a light tapping sound when in park goes away when in gear … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
I am looking for car deals with average paying 150-200 /
Second opinion] I am looking for car deals with average paying 150-200 / month ? Is there ay. Current deal around me here in NY… read more
Ted G.
Ted G.
ASE Certified Technician
Vocational, Technical or Trade Scho
1,724 satisfied customers
The key wont turn in the ignition. Turned it all the way
yes. turned it all the way left , then right key still wont turn. key does not seem damaged … read more
sprinkles08
sprinkles08
Technician
High School or GED
11 satisfied customers
Looking at buying a 2007 pacifica with the 4.0L seller says
looking at buying a 2007 pacifica with the 4.0L seller says it has a misfire … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,403 satisfied customers
Toyota sequoia 2002 Limited 4 wheel drive. Just replaced all
Toyota sequoia 2002 Limited***** Just replaced all the cords and plugs (whatever they are called now).Anyhow, the check engine light went out. But the VHS or whatever the skid marks are up in the top … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
My camry 96 year model cuts out when coming to slowing down
My camry 96 year model cuts out when coming to slowing down to stop, please help. Vince … read more
roy
roy
Associate Degree
3 satisfied customers
My 210 Suzuki Kizashi sometime will not start. Car display
My 210 Suzuki Kizashi sometime will not start. Car display says turn steering wheel in both directions to unlock. Can I get this function disabled rather then repairing, I hear it is a bit costly! … read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
The LED touchscreen went off four days ago. I have tried
The LED touchscreen went off four days ago. I have tried everything to bring up the touch screen. No luck. Also, the radio is not working. … read more
Eurocar Inc
Eurocar Inc
Master Audi/VW Tech
Associate Degree
1,773 satisfied customers
My radio (CUE) volume seems to be not working properly. It
My radio (CUE) volume seems to be not working properly … read more
Stephen, MBA
Stephen, MBA
Master's Degree
166 satisfied customers
I'm wondering if Exxon Synergy gas will hurt or harm my 2008
I'm wondering if Exxon Synergy gas will hurt or harm my 2008 Prius. … read more
kwiggins29059
kwiggins29059
Associate Degree
219 satisfied customers
I need to know the type of transmission is in a 2006 Dodge
I need to know the type of transmission is in a 2006 Dodge Caravan (3.3L) and also how many speeds there are: VIN # 1D4GP25R36B646548. Thank you.… read more
Edward Clayton
Edward Clayton
Associate Degree
1,033 satisfied customers
I have a 1995 C280 and there is no braking on the passenger
I have a 1995 C280 and there is no braking on the passenger side front wheel. … read more
Expert
Expert
15 satisfied customers
My truck is sputtering but only when I'm under load like
My truck is sputtering but only when I'm under load like during acceleration, I am throwing no codes so I'm not sure how to proceed … read more
vwtech0405
vwtech0405
VW Technician
Associate Degree
9,666 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