Silverado Manifold Gasket problem

Discussion in 'Domestics' started by Andy E, Mar 25, 2008.

  1. Andy E

    Andy E Newbie

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    My 03 Silverado 1500, 24K miles, sorry but I don't know the exact engine. 5. xl V8. Is at the dealer right now. It has been rough at idle and the check engine light has been on. The service advisor said the was a TSB about the Manifold Gasket and I believe he said it came up on the diagnostic. After doing some searching on the web, I can find nothing about the gasket and that truck. It all seems to be with smaller engines.

    The truck is out of warranty and I am looking at a $600+ repair.

    Can anyone offer any thoughts on if the coolant/gasket issue is a problem with these models or am I having an unneeded repair done?

    Thanks

    Andy
     
  2. Jim Fairbanks

    Jim Fairbanks wrench

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    I did find a tsb about a crack in the cylinder head on some of them...The 5.3 was one...It would help if you could tell us the engine size and the code)s that the dealer got when they scanned it.....Jim
     
  3. Gus

    Gus wrench

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    Well, well....working on a 2003 GMC yukon, with a 5.3....setting codes P0101, P0171, and P0174......Check P0101 first.....TSB or PIP to check the MAP to see if it sets a false MAF P0101 code...that was ok....Check for leaks in snorkel after MAF...OK.....spray carb cleaner at intake gaskets....voila!, that's the problem....TSB says check for warped plenum with feeler gage and flat rule....

    Told customer the outcome......wants to do it himself......methinks he is shopping around.....

    Basically on a cold startup, it runs super lean, causing a lean misfire(both O2 sensors running under 50mv in closed loop) due to the leak...spray carb cleaner at the intake gaskets and they jump up to 900mv immediately......as the vehicle warms up and things start to expand, it runs better as it starts to seal better...
     
  4. kev2

    kev2 wrench

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    Jim or Gus, could you post TSB # ....I do not see anything about it? ???

    Andy E ...give us some more to chew on. describe problems, observations drivability issues etc.. and as always the code or codes...
     
  5. Jim Fairbanks

    Jim Fairbanks wrench

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    Hey Kev2.....What I found is different from what Gus is talking about....Here it is....Jim....
    Bulletin No.: 06-06-01-019B

    Date: June 12, 2007

    INFORMATION

    Subject:
    Information on Gradual Coolant Loss Over Time With No Evidence of Leak Found

    Models:
    2004-2006 Buick Rainier
    2001-2006 Cadillac Escalade Models
    2001-2006 Chevrolet Avalanche, Blazer, Silverado, Suburban, Tahoe, TrailBlazer Models
    2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models
    2001-2004 Oldsmobile Bravada
    2005-2006 Saab 9-7X

    with 4.8L or 5.3L VORTEC(R) GEN III, GEN IV V8 Engine (VINs V, T, M, B, Z - RPOs LR4, LM7, LH6, L33, L59)

    Supercede:

    This bulletin is being revised to include engine RPO L59. Please discard Corporate Bulletin Number 06-06-01-019A (Section 06 - Engine/Propulsion System).

    Some vehicles may experience a gradual coolant loss over time. A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.

    Inspect the cylinder head assembly to determine if the casting was manufactured by Castech. This can be accomplished by inspecting for their casting logo located on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.

    If the cylinder head(s) are Not a Castech casting, follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

    Refer to the illustrations on how to identify Castech casting and/or the very specific areas of the cylinder head(s) for a coolant leak from porosity.

    Cylinder head(s) location of the Castech manufacturing casting logo (1).Close up view of the cylinder head(s) showing the Castech manufacturing casting logo (1).

    If the cylinder head(s) is a Castech casting (1), inspect the area around the five oil drain holes for witness marks indicating coolant seepage over time (2).

    If No evidence of coolant loss is found on inspection of Castech casting cylinder head(s), follow normal diagnostic procedures in SI to determine the cause of the coolant loss.

    The crack location can be found in any of the five cylinder head(s) oil drains. This can be seen as a clean or shiny area, on an otherwise stained surface (1). Pressurizing the cooling system at this time may reveal coolant, air, or a combination, weeping in the described area. If inspection reveals evidence of coolant witness marks (1), replace the entire cylinder head(s) assembly.




    [attachment deleted by admin]
     
  6. Andy E

    Andy E Newbie

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    Thanks for the quick responses, guys.

    I am pretty sure it is the 5. 3L

    I am at work and my wife dropped off the car this morning. Middle of last week I noticed at a stop light that it was idling really rough. Seemed to calm a bit as it got warmed up. Engine light has been on and off over the last week, and idle problems have come and gone. Last night pulling into the driveway I noticed the lights dim a bit as the engine sounded like it was going to stall.

    I spoke to the SA at the dealer this afternoon and he said there was a TSB about the gasket and he got a code for an O2 sensor also. I didn't get which sensor. I had one replace under warranty in 05. Had no idea they retail for $120. ouch.

    I can't say as I have noticed any coolant leakage. I drive to the train and back (about 7 miles round trip) and around town for errands. Bought the truck 10/02 and have just under 25k on it. I use it for firewood and fishing trips so it doesn't see much highway use.

    If the service manager returns my call I will try to get what codes they got on it.

    Thanks again.

    Andy
     
  7. EricC

    EricC Hero Member

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    I believe this is the one we are looking for. The above bulletin addresses cylinder heads and coolant leakage. There is no coolant running through Gen 3 engine intakes.

    #PIP3232B: Cold Engine Idle Misfire Or DTCs P0171 P0174 - keywords 4.8 5.3 6.0 air cold crack hesitate idle intermittent internal intake leak lean misfire miss P0171 P0174 P0300 power rough surge vacuum - (Feb 7, 2007)


    Subject: Cold Engine Idle Misfire or DTCs P0171 P0174


    Models: 2002-2005 Cadillac Escalade

    1999-2005 Chevrolet Avalanche, Express, Silverado, Suburban, Tahoe, Trailblazer

    1999-2005 GMC Savana, Sierra, Yukon

    2003-2005 Hummer H2




    --------------------------------------------------------------------------------

    This PI was superseded to update parts information. Please discard PIP3232A.


    --------------------------------------------------------------------------------

    The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

    Condition/Concern:
    99 through 05 GEN III truck engines may experience any of the following:

    A cold rough idle that diminishes as the engine warms up.
    Possible DTCS P0171, P0174, or P0300.
    Random misfires at idle.
    Recommendation/Instructions:
    The intake gasket seals may be leaking around the intake ports, causing a lean condition. The intake gasket seals may leak around the bottom side of the port, making it a challenge to detect the vacuum leak. The technician may also notice lower than normal MAF readings if the intake seals are leaking.

    If leaking intake gasket seals are found, replace the intake gaskets. During the repair be sure to use the current GMSPO part number for replacement intake gaskets. The current GMSPO part number for intake gaskets will have a teal green intake gasket seal. The old version of the intake gaskets were orange in color. Use only the teal green colored gaskets for a repair.
    The intake plenum should also be checked for excessive warpage that may cause an uneven clamping pressure of the seal. If the plenum is found to be warped it will need to be replaced. Service Information states, "An intake manifold with warpage in excess of 3 mm (0.118 in) over a 200 mm (7.87 in) area should be replaced". Intake warpage is measured at the gasket sealing surfaces, and should be measured within a 200 mm (7.87 in) area. This measurement is across only two of the intake runner port openings. Measurements taken across the entire distance of all four intake runner ports will lead to unnecessary manifold replacements.
    Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

    GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

    WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


    © 2008 General Motors Corporation. All rights reserved.
     
  8. Andy E

    Andy E Newbie

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    The truck got picked up today, and has had the manifold gasket(s) replaced and one of the 02 sensors replaced. I haven't been home yet but will update with the codes tomorrow
     

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