GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 4 of 4
  1. #1

    Default Help! 1999 Chevy Suburban Runs Rough

    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. #2
    murdog94's Avatar
    Join Date
    Feb 2008
    Cloquet, Minnesota, United States
    Blog Entries


    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.


    1997 Chevy S-10 Blazer 4X4 with 330K miles and counting (Hunting rig).

    2009 Saturn Aura XE (wifes car)

    2011 F-150 Crew 4X4

    "Hold it to the floor till you see God.... Then Brake!!!!"

  3. #3


    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.

    1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4.10 gears 200K miles
    2005 Saturn ION-2 Stock 265K miles
    1982 Bronco, 1993 Bronco (sold), 1971 M35A2 Deuce and a Half

    There are 10 kinds of people, those who understand binary, and those who dont...

    Remember kids, the only difference between screwing around and science is writing it down- Adam Savage

  4. #4


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

    1999 Chevy K2500 Suburban 350
    K&N, reworked cai, Thrush cat-backs
    Vinyl, cranks, floor shift, and rear air!

Similar Threads

  1. '96 Sub Runs rough, again.
    By MichaelJT in forum GM Powertrain
    Replies: 9
    Last Post: 08-30-2010, 01:37 PM
  2. Egine runs rough while idling
    By Bear945 in forum General Chevy & GM Tech Questions
    Replies: 4
    Last Post: 09-12-2009, 03:21 PM
  3. 1999 Suburban 5.7 Runs Rough-need some help.
    By jtriplett in forum GM Powertrain
    Replies: 23
    Last Post: 08-04-2009, 09:07 AM
  4. Motor runs rough and loud at start up
    By mjmar4978 in forum General Chevy & GM Tech Questions
    Replies: 3
    Last Post: 12-06-2008, 06:48 PM
  5. Need help, engine won't idle, runs rough
    By rickyg1 in forum Performance & Fuel
    Replies: 23
    Last Post: 09-09-2007, 09:44 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts