Page 1 of 2 12 LastLast
Results 1 to 13 of 20
  1. #1
    Join Date
    Feb 2004
    Location
    Midwest
    Posts
    9,932

    Service engine soon light on Chevy Van?

    When I'm on the highway going up a hill, the engine seems to lose power and the "service engine soon" light starts flashing. When I crest the hill and hit level ground, both things stop.

    What would cause that?

  2. #2
    Join Date
    Nov 2008
    Posts
    1,673
    Bad head gasket? (Do a compression test). Rarely, it passes and the head gasket is still bad.
    Or, bad electronics telling the engine to behave that way.

    I just lately discovered that my local library had a book on exam questions that people can use to bone up for their ASE certification exam.
    This book has a lot of useful troubleshooting info, but it's not arranged in that order. Still, if you can wade through the questions and answers you may find exactly your symptoms and the cause.

    There doesn't seem to be a generic troubleshooting book for cars, except for two volume sets that cost $600 and are vehicle-specific. Motor's and Chilton's used to publish books along this line but these companies might have become victims of the Internet.

    Turns out it costs more money for the library to keep these kinds of books on their shelves than to sign up for online auto data services. If your make and model are in the library's version of the database, it might have some troubleshooting instructions. The older the car the more likely you'll find what you want.

    I buy my $25 Chilton/Haynes manuals for my vehicles before I need them. Factory Service Manuals for new cars now cost $400 or so, and a lot of the procedures in them you can't do because you need special equipment.

    Any time you work on your own vehicle you are paying yourself at least 30 tax-free dollars per hour, even if the job takes you the whole day.

  3. #3
    Join Date
    Jul 2008
    Location
    Denver, CO
    Posts
    4,229
    Take it to someone with a diagnostic interface and have them pull the code history and see what they come up with.

  4. #4
    Join Date
    Oct 2002
    Location
    Yo.... Here!, I'm right here..
    Posts
    6,236
    Catalytic converter........??.............or...............w ell ......it is a Chevy...............

  5. #5
    Join Date
    Dec 2004
    Location
    newton,mass.
    Posts
    6,109
    Quote Originally Posted by WhoIsThat? View Post
    Bad head gasket? (Do a compression test). Rarely, it passes and the head gasket is still bad.

    I just lately discovered that my local library had a book on exam questions that people take to get their ASE certification.
    This book has a lot of useful troubleshooting info, but it's not arranged in that order. Still, if you can wade through the questions and answers you may find exactly your symptoms and the cause.

    There doesn't seem to be a generic troubleshooting book for cars, except for two volume sets that cost $600 and are vehicle-specific.
    Motor's and Chilton's used to publish books along this line but these companies might have become victims of the Internet.
    I buy my $25 Chilton/Haynes manuals for my vehicles, before I need them.

    My truck has done the same thing for almost seven years, I was told what you are saying ...they checked and everything was OK. I then heard that the programming was updated and they just change an e-prong and all is well. I never bothered to get it changed, I only drive down hills now, seems to work ...



    .
    "Nothing else can poison our culture, corrupt our society or ruin the character of our people like unearned money or unearned opportunity." -- James R. Cook

    "Fooling around with alternating current is just a waste of time. Nobody will use it, ever." Thomas Edison, 1889.

  6. #6
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    3,181
    Quote Originally Posted by midhvac View Post
    When I'm on the highway going up a hill, the engine seems to lose power and the "service engine soon" light starts flashing. When I crest the hill and hit level ground, both things stop.

    What would cause that?
    I would start with a fuel filter. Has it lost its power in passing gear too ?

    Back in the day that would point to a fuel pump going bad , but your is lectric now so Im going with the filter

  7. #7
    Join Date
    Mar 2004
    Location
    SE Michigan
    Posts
    17,960
    Bad O2 sensor?
    Behind the ostensible government sits enthroned an invisible government owing no allegiance and acknowledging no responsibility to the people.

    Theodore Roosevelt

  8. #8
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    18,589
    Quote Originally Posted by WhoIsThat? View Post
    Bad head gasket? (Do a compression test). Rarely, it passes and the head gasket is still bad.
    Or, bad electronics telling the engine to behave that way.

    I just lately discovered that my local library had a book on exam questions that people can use to bone up for their ASE certification exam.
    This book has a lot of useful troubleshooting info, but it's not arranged in that order. Still, if you can wade through the questions and answers you may find exactly your symptoms and the cause.

    There doesn't seem to be a generic troubleshooting book for cars, except for two volume sets that cost $600 and are vehicle-specific. Motor's and Chilton's used to publish books along this line but these companies might have become victims of the Internet.

    Turns out it costs more money for the library to keep these kinds of books on their shelves than to sign up for online auto data services. If your make and model are in the library's version of the database, it might have some troubleshooting instructions. The older the car the more likely you'll find what you want.

    I buy my $25 Chilton/Haynes manuals for my vehicles before I need them. Factory Service Manuals for new cars now cost $400 or so, and a lot of the procedures in them you can't do because you need special equipment.

    Any time you work on your own vehicle you are paying yourself at least 30 tax-free dollars per hour, even if the job takes you the whole day.
    You probably found one of the ASE books I wrote for a major auto publisher. I did not ask for, nor receive a "by" line. I hope it helped you, but it is focused on test prep, and not check engine diagnostics.

    You need a scan tool, either an OBD I or II, depending on the model year. Once you have the code, you look up the code in the appropriate manual, and follow the diagnostic tree. By the time you are finished, you will probably have spent more on the scan tool and the book that it would cost to take it to a shop and have them test the vehicle. Companies like Alldata are very good at preventing their info from being disseminated freely.

    Older GM vehicles of the OBD I vintage can flash the check engine light when you short the A and B terminals of the ALDL connector.

    Perhaps the least expensive and time consuming approach is to make sure all of the vehicle maintenance is up to snuff. Odd things can exist after that, like the innards of the cat sliding against the outlet of the cat when powering uphill and stifling the exhaust, and then falling away from the outlet when traveling downhill, allowing the exhaust to flow again. Or water in the fuel tank that gets sucked up at a specific angle can cause problems.

    Start with maintenance, then take it in for diag when everything has been attended to.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  9. #9
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    18,589
    Quote Originally Posted by vmc1161 View Post
    My truck has done the same thing for almost seven years, I was told what you are saying ...they checked and everything was OK. I then heard that the programming was updated and they just change an e-prong and all is well. I never bothered to get it changed, I only drive down hills now, seems to work ...



    .
    GM pickups had an eprom update due to a knock sensor problem. Really irritated their customers, too. Of course, the recent "like a knock" problem that came from the abandonment of a "select fit" approach to engine building was a lot more irritating.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  10. #10
    Join Date
    May 2004
    Location
    Austin, TX
    Posts
    1,733
    I am with coolwhip, O2 sensor starting to go bad...

  11. #11
    Join Date
    Jun 2004
    Location
    Howell, Michigan
    Posts
    16,176
    Quote Originally Posted by Roscoe View Post
    Catalytic converter........??.............or...............w ell ......it is a Chevy...............
    LOL......................Agreed! Hey! I found something on ebay that will make your cube van look better, bought a set myself.

    Ford Factory Aluminum Wheels

    You need to buy the rear caps for the full floating axle though.

  12. #12
    Join Date
    Jan 2007
    Location
    Coloma MI
    Posts
    214
    Since it only does it going uphill with added load.... I'm putting my money on a misfire code. Go to AutoZone, they'll pull the codes for free. Misfires occur under heavy load with old spark plugs or a bad plug wire.

  13. #13
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    18,589
    Quote Originally Posted by SJProwler View Post
    Since it only does it going uphill with added load.... I'm putting my money on a misfire code. Go to AutoZone, they'll pull the codes for free. Misfires occur under heavy load with old spark plugs or a bad plug wire.
    That's why you check yourself on the maintenance first.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event