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  1. #1

    Default Water leaking from muffler

    I have a 2011 4x4 Tahoe. It has a little over a thousand miles on it. Easy around town driving for the most part.
    I ran a few errands today & noticed every time I parked, water or fluid was dripping out of the muffler. Right where
    the back seat door is, I bent down to look underneath. Before muffler meets pipes. Is this normal? Seems like alot to me.
    My first ride is a 2011 Chevy Tahoe
    My second ride is a 2005 Chevy Trailblazer
    My third ride is an American Quarter Horse

  2. #2


    it is most likely condensation forming on the hot muffler and within it. this water is created durring normal combustion its basic chem
    2 C8H18 + 25 O2 → 16 CO2 + 18 H2O
    Last edited by Conlan Rose; 03-08-2012 at 07:06 PM.

    1996 Chevy Tahoe LT 5.7L V8 4X4 205,000+ miles. Built proudly at Janesville Assembly in Janesville, Wisconsin
    Basic mods: Lights all over, bunch of electrical work, and a couple cooling mods.

    Check out my other mods in My Garage:

  3. #3


    Thanks so much for your quick reply. Just seemed an abnormal amount since it was running down the driveway.

  4. #4
    Sr. Apprentice
    Join Date
    Nov 2008
    Endicott, NY


    You need to put about 30 miles of highway driving on the vehicle and then check to see if there is any liquid coming out. Making short trips doesn't allow the exhaust system to heat up. As posted above exhaust gas has a lot of water in it and if the piping/mufflers aren't hot enough to keep it in gaseous form it will condense and find its way out of the nearest point hole. I don't know how far you have to go to get it hot but I do know 30 miles will do it. If you are still getting a lot of fluid out after driving a long distance then you might have a problem.


  5. #5


    there is a little drain hole at the end of the muffler so condensation can escape. Hopefully resulting in a muffler that dosen't rust out!

  6. #6
    Sr. Engineer Dana W's Avatar
    Join Date
    Dec 2011
    Chuluota, Florida


    Naaaah, it's a worn out muffler bearing.

  7. #7


    Quote Originally Posted by Dana W View Post
    Naaaah, it's a worn out muffler bearing.

    If at first you don't succeed, get a bigger cheater bar.

    1999 GMC Sierra SLT Z71 | 5.3 "Vortec" | Spectre "Cold Air Intake" | TransDapt TBS | Hypertech 30005 Tune | 2005 Chevy Tail Lights | Denali headlights | Grill Mounted Fog Lights | AWS Bug Shield | 265/70/16 Futura Scramblers | Boss HD Speakers | 2005 Overhead Console | Flowmaster Super 40 mufflers 2N1O | Mostly stock-ish
    Bigger Amp Alternator | Electric Fans | Transmission Fluid cooler | Paint (Halfway there)| Interior Restoration/Upgrade with newer model parts | Window Visors (In channel) | Tint | Low-Profile Tool Box | LEDs throughout stock cab locations (68% Done) | And whatever is spurr of the moment
    CVN-69 "IKE-ATRAZ" AIR/V-2 Gear Dawgs

  8. #8


    ive heard of this, its from the muffler fluid not being changed.


    2011 GMC Sierra SLE 5.3 Z71 4X4 Stealth Gray Metallic / 2004 Chevy Impala LS 3.8 Cappuccino

    Tow mirrors - Diablew Tuned - Flowmaster Regular 40 - Ready Lift 2.5' lift - BFG LT A/T K/Os - Carr Light Wing - TruckLite LED lights - Optima Red Top - 50% Front Window Tint - Line-X bedliner - Airaid MIT - Tekonsha P2 - ARS Billet Grill - Fia custom fit seat covers

  9. #9


    We have a lot of characters here but in all seriousness, if the shop guy did not change the muffler fluid when you had your oil changed...... OOPs

    As mentioned above the moisture can build up when weather is cool and exhaust doesnt get hot enough to create a gas to exit through the tail pipe.
    Take a good drive and get it warmed up then recheck. Allowing the condensation to remain in the muffler for long periods of time will cost money for a new muffler far too soon.
    2010 Chevy Silverado Z71 ext cab.4x4
    72 Monte Carlo 350-415 hp- sold (June 2011) to pay medical bills
    79 Impala 350 4bbl 375 hp- sold (June 2011)to pay medical bills

    "If He asks you to go a mile go two"

  10. #10


    All the guys above are correct, moisture (condensation) will form inside the muffler and drip out of the tailpipe.

    But, there are other places for condensation to originate, the front (underhood) ac will drip condensation under the truck (but this is at the front); however, if you have a rear ac system, condensation can/will drip from that. The rear system has a hose that lets water drip from the area under the seat.

    If you were driving with the rear ac turned on, try if with the rear turned off and see if the dripping stops.

    '09 Avalanche LTZ - Black
    '05 Envoy XL (sold)

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