Help! 1999 Chevy Suburban Runs Rough

Discussion in 'GM Powertrain' started by slacktide, Sep 28, 2010.

  1. slacktide

    slacktide New Member

    First off, I just found this site and find the information great...

    I have a 1999 Suburban with a Vortec 5.7... It has been a great truck just hitting 300,000 miles this week. Problem is that it idles rough...real rough. It was fine until I was on an extended trip through the mountains when I blew a hole in the radiator hose... it quickly overheated and cut off... I waited for it to cool, refilled the coolant and limped home... After repairs to the hose, it has never run correctly again.

    The car runs and drives, but will not idle correctly and is always on the verge of cutting off... I have changed out the EGR, PCV valves with no luck... would a simple tune up correct the problem or should I look for something else...

    Money is kinda tight (as it is everywhere) .. and I thought the EGR valve was the solution but it wasn't so any thoughts would be helpfull

  2. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    First is the check engine light on? If so you will want to start there. Also a good throttle body cleaning wouldnt be a bad idea, just pick up a can of throttle body cleaner, remove the throttle body and clean it up to look like new to include the IAC port etc...
    But if you have a check engine light while you are at the parts store they should be able to loan you (in their parking lot) a OBDII reader, that will be able to pull any engine trouble codes.
  3. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    Depending on how long you ran it without coolant before realizing it and stopping, you may have a warped head or a blown head casket. Check the coolant for oil and the oil for coolant. Coolant getting into the cylinders because of a blown head gasket would make the engine shudder bad.
  4. KidHauler

    KidHauler Epic Member 5+ Years 500 Posts

    X2, plus check for white smoke and coolant smell at the exhaust.

Share This Page

Newest Gallery Photos