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  1. #1

    Exclamation 1995 C1500 Suburban runs great, then out of blue rough.

    My truck runs perfectly fine then out of the blue it gets really loud and goes through revs really rough. Still shifts fine and doesn't jerk. But it kind of feels like it loses power when this starts happening. Then it goes away runs fine again and returns randomly. I just had the tranny serviced and there was no shaving's and everything looked clean. Just last week changed the cap/rotor/wires/plugs to see it made any difference and still nothing. Any ideas to what's causing this? It's the 5.7 tbi engine.

  2. #2

    Default

    Try running some sea-foam thru your vacuum line off your brake booster and see if that helps anything

    2009 Chevrolet Silverado 1500 LT Z71 Crew Cab "All-Star Edition"

    Line-X'd Bed
    Line-X'd Custom Brush Guard(Heavy Duty)
    5.3L Flex Fuel
    275/65R18 Toyo Open Country AT2's
    2" Rough Country Leveling Kit(want to get the 2.5 RC kit)
    EGR In-Channel Vent Visors
    Exterior PLUS Package
    Interior PLUS Package
    K&N Drop-In Air Filter
    ProFlaps
    Cat-Back Dual Exhaust
    Black Bowties
    Diablo Sport Predator(AFM Disabled)
    ProFlaps
    Towing Mirrors
    Next Planned Mods
    Blacked out Tail Lights
    Aftermarket Rims

  3. #3

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    Quote Originally Posted by Skyline View Post
    My truck runs perfectly fine then out of the blue it gets really loud and goes through revs really rough. Still shifts fine and doesn't jerk. But it kind of feels like it loses power when this starts happening. Then it goes away runs fine again and returns randomly. I just had the tranny serviced and there was no shaving's and everything looked clean. Just last week changed the cap/rotor/wires/plugs to see it made any difference and still nothing. Any ideas to what's causing this? It's the 5.7 tbi engine.
    Any Check engine lights?

  4. #4

    Default

    No, none at all. Last time it had a check engine light it was the EGR and I already replaced that. Never came back.

  5. #5

    Default

    Quote Originally Posted by Skyline View Post
    No, none at all. Last time it had a check engine light it was the EGR and I already replaced that. Never came back.
    :-/ ...

    Runs fine then randomly gets loud and revs slow..

    Couple of questions:
    When was the last tune-up done on the truck.
    Miles on current plugs / wires / cap / rotor.


    Maybe a Cat is backing up / failing? Could remove the y pipe and take a gander in the catylitic converters to see if they are comming apart internally...

  6. #6

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    Last time I serviced the transmission was 2 days ago. Thought it would go away then returned. The last time I changed the cap/rotor/plugs/cables was about 8 days ago. So they have maybe like 200 miles on them. Mechanic friend thought it could be the tranny shift solenoids, but I really doubt that because it shifts like a champ even when this happens.

  7. #7
    Legend

    Join Date
    Feb 2008
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    Red Wing, Minnesota, United States
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    Default

    Does your truck have a MAF senser, they can go bad and not throw codes. IAC as well will give all kinds of problems and may not show a code.
    99 K1500 Suburban LT "THE BEAST"
    Hypertech III, K&N, true dual
    285/75/16
    ___________________________
    Jason

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