How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Randall C Your Own Question

Randall C
Randall C, ASE Master Tech
Category: Chevy
Satisfied Customers: 11193
Experience:  ASE Master, L1, 32 years, Diagnostic / Electrical Specialist
13677702
Type Your Chevy Question Here...
Randall C is online now
A new question is answered every 9 seconds

Replace a Manifold Gasket for a 2003 Chevy Silverado V6 4.3 L engine?

Customer Question

How do you replace a Manifold Gasket for a 2003 Chevy Silverado V6 4.3 L engine?
Submitted: 5 years ago.
Category: Chevy
Expert:  Randall C replied 5 years ago.

Hello, this is a 2 step process. There is an upper intake and lower. The first set is for the upper. the next post has the lower

 

Intake Manifold Replacement - Upper

Removal Procedure

  1. Remove the fuel pipes/hoses.
  2. Disconnect the cruise control cable from the throttle lever, if equipped.

  1. Remove the cruise control cable from the accelerator control cable bracket, if equipped.

  1. Remove the accelerator cable from the throttle body lever.

  1. Remove the accelerator cable from the accelerator control cable bracket.

  1. Disconnect the following electrical connectors:
    • The Air Conditioning (A/C) compressor clutch (1), if equipped
    • The A/C pressure switch (4), if equipped
  1. Remove the engine wiring harness clip (3) from the accelerator control cable bracket.

  1. Remove the accelerator control cable bracket nuts.
  2. Remove the accelerator control cable bracket with the cables attached, from the throttle body.
  3. Reposition and secure the bracket and cables out of the way.

  1. Disconnect the following electrical connectors:
    • The Throttle Position (TP) sensor (1)
    • The Idle Air Control (IAC) motor (2)
    • The control port injector module (3)
  1. Remove the engine wiring harness clip bolt (4).

  1. Disconnect the following electrical connectors:
    • The Evaporative Emission (EVAP) canister purge solenoid valve (1)
    • The Manifold Absolute Pressure (MAP) sensor (2)

  1. Disconnect the EVAP canister harness from the purge solenoid valve.

  1. Remove the engine wiring harness bracket nuts.
  2. Remove the engine wiring harness bracket.

  1. Remove the engine wiring harness ground nut and ground wire (4) from the rear of the right cylinder head.

  1. Remove the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve.
  2. Remove the stud holding the engine wiring harness bracket.
  3. Reposition the engine wiring harness with the bracket aside.

  1. Remove the PCV valve hose from the valve and rocker cover.

  1. Disconnect the power brake booster vacuum hose from the vacuum fitting.

  1. Remove the accelerator cable bracket nuts.
  2. Remove the accelerator cable bracket.

  1. Remove the intake manifold - upper studs.
  2. Remove the front two throttle body studs.
  3. Remove the intake manifold - upper.

  1. Remove and discard the intake manifold - upper gasket.

  1. Remove and discard the O-ring seal from the fuel meter body.

  1. If required, remove the power brake booster vacuum fitting.
  2. Remove and discard the O-ring seal.

  1. If required, remove the PCV valve cover.
  2. Remove and discard the O-ring seal.

  1. If required, remove the rear throttle body stud.
  2. Remove the throttle body.
  3. Remove and discard the throttle body gasket.

  1. If required, remove the MAP sensor.
  2. Remove and discard the MAP sensor seal.

  1. If required, remove the EVAP canister purge solenoid valve studs.
  2. Remove the purge solenoid valve.
  3. Clean and inspect the intake manifold - upper, if necessary.
Expert:  Randall C replied 5 years ago.

Intake Manifold Replacement - Lower

Removal Procedure



Important:

  • The intake manifold may be removed as an assembly. Do not remove the specific intake manifold components unless component service is required.
  • It is not necessary to remove the upper intake manifold in order to remove the lower intake manifold.
  • Do not allow dirt or debris to enter the fuel system. Ensure that the ends of the fuel system are properly sealed.
  • Do not disassemble the central sequential fuel injection (SFI) unit, unless service is required.
  1. Drain the cooling system.
  2. Remove the fuel pipes/hoses.
  3. Remove the distributor.

  1. Disconnect the Evaporative Emission (EVAP) canister harness from the purge solenoid valve.

  1. Remove the heater hose clamp (1).

  1. Open the heater outlet hose clamp and remove the hose from the intake manifold.

  1. Open the heater inlet hose clamp and remove the hose from the water pump.
  2. Reposition the heater inlet and outlet hoses.

  1. Disconnect the cruise control cable from the throttle body lever, if equipped.
  2. Remove the cruise control cable from the accelerator control cable bracket, if equipped.

  1. Remove the accelerator cable from the throttle body lever.

  1. Remove the accelerator cable from the accelerator control cable bracket.

  1. Disconnect the following electrical connectors:
    • The Air Conditioning (A/C) compressor clutch (1), if equipped
    • The A/C pressure switch (4), if equipped
  1. Remove the engine wiring harness clip (3) from the accelerator control cable bracket.

  1. Remove the accelerator control cable bracket nuts.
  2. Remove the accelerator control cable bracket with the cables attached, from the throttle body.
  3. Reposition and secure the bracket and cables out of the way.

  1. Disconnect the following electrical connectors:
    • The Throttle Position (TP) sensor (1)
    • The Idle Air Control (IAC) motor (2)
    • The control port injector module (3)
  1. Remove the engine wiring harness clip bolt (4).

  1. Disconnect the following electrical connectors:
    • The Evaporative Emission (EVAP) canister purge solenoid valve (1)
    • The Manifold Absolute Pressure (MAP) sensor (2)

  1. Remove the engine wiring harness bracket nuts.
  2. Remove the engine wiring harness bracket.

  1. Remove the engine wiring harness ground nut and ground wire (4) from the rear of the right cylinder head.

  1. Remove the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve.
  2. Remove the stud holding the engine wiring harness bracket.
  3. Reposition the engine wiring harness with the bracket aside.

  1. Remove the PCV valve hose from the valve cover and rocker cover.

  1. Disconnect the power brake booster vacuum hose from the vacuum fitting.

  1. Reposition the radiator inlet hose clamps.
  2. Remove the radiator inlet hose from the thermostat housing.

  1. Reposition the water pump inlet hose clamps.
  2. Remove the water pump inlet hose.

  1. In order to remove the front intake manifold bolt, perform the following:
33.1.Remove the drive belt.
33.2.Loosen the Power Steering (P/S) pump rear bracket nut.
33.3.Remove the P/S pump rear bracket front nut.
33.4Remove the bolts and the nut for the P/S pump bracket.
33.5.Leave the A/C compressor, if equipped, and the P/S pump on the bracket.
33.6.Slide the P/S pump bracket forward to access the front intake manifold bolt.

  1. Remove the intake manifold - lower bolts.
  2. Remove the intake manifold.
  3. Remove and discard the intake manifold gaskets.
  4. Clean and inspect the intake manifold - lower, if necessary.

Installation Procedure

Notice:Apply the proper amount of the sealant when assembling this component. Excessive use of the sealant can prohibit the component from sealing properly. A component that is not sealed properly can leak leading to extensive engine damage.
  1. Apply a 4.0 mm (0.157 inch) patch of adhesive GM P/N 12346141, (Canadian P/N 10953433), or equivalent to the cylinder head side of the intake manifold gasket at each end.
Important:The intake manifold gasket must be installed while the adhesive is still wet to the touch.
  1. Install the intake manifold gasket onto the cylinder head. Use the gasket locating pins in order to properly seat the gasket.

Important:The intake manifold must be installed and the fasteners tightened while the adhesive is still wet to the touch.
  1. Apply a 5 mm (0.197 inch) bead of adhesive GM P/N 12346141, (Canadian P/N 10953433), or equivalent to the front top of the engine block.
  2. Extend the adhesive bead 13 mm (0.50 inch) up onto each intake manifold gasket.

  1. Apply a 5 mm (0.197 inch) bead of adhesive GM P/N 12346141, (Canadian P/N 10953433), or equivalent to the rear top of the engine block.
  2. Extend the adhesive bead 13 mm (0.50 inch) up onto each intake manifold gasket.

  1. Install the intake manifold.
  2. If reusing the old fasteners, apply threadlock GM P/N 12345382, (Canadian P/N 10953489), or equivalent to the threads of the intake manifold - lower bolts.
  3. Install the intake manifold - lower bolts.

Intake Manifold Bolt Sequence


Notice: Proper lower intake manifold fastener tightening sequence and torque is critical. Always follow the tightening sequence, and torque the intake manifold bolts using the 3 step method. Failing to do so may distort the crankshaft bearing bore alignment and cause damage to the crankshaft bearings.

Notice: Refer to Fastener Notice in Service Precautions.
See: Service Precautions\Vehicle Damage Warnings\Fastener Notice

  1. Tighten the intake manifold - lower bolts in the sequence shown.
10.1.Tighten the bolts a first pass to 3 Nm (27 inch lbs.).
10.2.Tighten the bolts a second pass to 12 Nm (106 inch lbs.).
10.3.Tighten the bolts a final pass to 15 Nm (11 ft. lbs.).

  1. Slide the P/S pump bracket rearward.
  2. Install the bolts and the nut for the P/S pump bracket.
  3. Install the P/S pump rear bracket front nut.
  4. Tighten the P/S pump rear bracket nut. Tighten the bolts and nuts to 41 Nm (30 ft. lbs.).
  5. Install the drive belt.

  1. Install the water pump inlet hose.
  2. Position the water pump inlet hose clamps.

  1. Install the radiator inlet hose to the thermostat housing.
  2. Position the radiator inlet hose clamps.

  1. Connect the power brake booster vacuum hose to the vacuum fitting.

  1. Install the PCV valve hose to the valve cover and rocker cover.

  1. Position the engine wiring harness and bracket.
  2. Install the engine wiring harness bracket stud.40 Tighten the stud to 25 Nm (18 ft. lbs.)
  3. Install the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve. Tighten the nut to 9 Nm (80 inch lbs.).

  1. Install the engine wiring harness ground nut and ground wire (4) to the rear of the right cylinder head. Tighten the nut to 16 Nm (12 ft. lbs.).

  1. Install the engine wiring harness bracket.
  2. Install the engine wiring harness bracket nuts. Tighten the nuts to 12 Nm (106 inch lbs.).

  1. Connect the EVAP canister harness to the purge solenoid valve.

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
< Last | Next >
  • http://ww2.justanswer.com/uploads/TI/tim37857/2011-10-28_23053_S6301814.64x64.JPG Tim's Auto Repair's Avatar

    Tim's Auto Repair

    mechanic

    Satisfied Customers:

    7641
    Have owned a repair shop for 25 yrs.
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    6870
    ASE Master Certification. GM World Class Certification
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    Chevy Technician

    Satisfied Customers:

    5404
    15 years GM master tech
  • http://ww2.justanswer.com/uploads/testedtuff/2009-09-26_170108_pictures.jpg John's Avatar

    John

    Master A.S.E Automotive technician

    Satisfied Customers:

    4071
    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • http://ww2.justanswer.com/uploads/RO/rodcuda/2011-7-25_224114_Donhoff1.64x64.JPG Neal's Avatar

    Neal

    Chevy Mechanic

    Satisfied Customers:

    2306
    Shop Owner and Mechanic on multiple makes.
  • http://ww2.justanswer.com/uploads/goodwrench9124/2008-11-09_220838_dscf0007.jpg goodwrench9124's Avatar

    goodwrench9124

    ASE Certified Technician

    Satisfied Customers:

    2041
    Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer, Hybrid certified
  • http://ww2.justanswer.com/uploads/DR/drivefast1971/2012-1-12_172422_0009051tQKh.64x64.jpg Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    1912
    18+yrs experience. State Inspector and Chevy Diagnostics