CAMPAIGN:UPPER INTAKE MANIFOLD GASKET DISTORTION
U.S. Campaign Number Cross Reference: 96-C-35 --------------------------------------------
Models: 1996 Chevrolet and GMC C,K,P Trucks Equipped With 7.4L (L29) Engines --------------------------------------------------------------------
TO: ALL GENERAL MOTORS DEALERS
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General Motors of Canada Limited has decided that CERTAIN 1996 Chevrolet and GMC C,K,P truck model vehicles equipped with 7.4L engines (RPO L29 - VIN Engine Code J) may exhibit a condition in which the upper intake manifold gaskets do not properly seal between the upper and lower intake manifolds. When this condition occurs, there may be unmetered air pulled into the upper intake manifold causing complaints of rough idle, hesitation, hissing noise, engine stalling and/or a Malfunction Indicator Light (MIL).
To prevent the possibility of this condition occurring, dealers are to replace the upper intake manifold gaskets and apply GM Threadlocker Loctite 272 to the upper manifold bolts.
VEHICLES INVOLVED:
Involved are certain 1996 Chevrolet and GMC C,K,P truck model vehicles equipped with 7.4L engines (RPO L29 - VIN Engine Code J) and built within the following VIN breakpoints:
Year Model Plant Plant Code From Through 1996 Chev C/K Pontiac East E SOP TE190403 1996 Chev C/K Fort Wayne Z SOP TZ160780 1996 Chev C/K Flint F SOP TF012247 1996 Chev C/K Janesville J SOP TJ361070 Suburban 1996 Chev C/K Janesville J SOP TJIO8190 HD3500 1996 Chev C/K Silao G SOP TGI30237 1996 Chev P Detroit 3 SOP T3305163 1996 GMC C/K Pontiac East E SOP TE529122 1996 GMC C/K Fort Wayne Z SOP TZ521662 1996 GMC C/K Janesville J SOP TJ511652 HD3500 1996 GMC C/K Silao G SOP TG510281 1996 GMC C/K Flint F SOP TF012247 1996 GMC C/K Janesville J SOP TJ726044 Suburban
NOTE: PLEASE CHECK DCS SCREEN 445 OR YOUR V.I.N. LISTING BEFORE PERFORMING CAMPAIGN TO ENSURE THAT THE VEHICLE AFFECTED. ONLY AFFECTED VIN'S WILL BE PAID.
All affected vehicles have been identified by the VIN listing provided to involved dealers with this bulletin. Any dealer not receiving a listing was not shipped any of the affected vehicles.
DEALER CAMPAIGN RESPONSIBILITY:
All unsold new vehicles in dealer's possession and subject to this campaign must be held and inspected/repaired per the Service Procedure of this Campaign Bulletin before owners take possession of these vehicles.
Dealers are to perform this campaign on all involved vehicles at no charge to owners, regardless of kilometres travelled, age of vehicle, or ownership, from this time forward.
Owners of vehicles recently sold from your new vehicle inventory with no owner information indicated on the dealer listing, are to be contacted by the dealer, and arrangements made to make the required correction according to instructions contained in this bulletin. This could be done by mailing to such owners a copy of the owner letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the owner may not as yet have received the notification letter.
In summary, whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.
CAMPAIGN PROCEDURE:
Refer to Section 4 of the Service Policies and Procedures Manual for the detailed procedure on handling Product Campaigns. Dealers are requested to complete the campaign on all transfers as soon as possible.
OWNER NOTIFICATION:
All owners of record at the time of campaign release are shown on the attached computer listing and have been notified by first class mail from General Motors (see copy of owner letter included with this bulletin). The listings provided are for campaign activity only and should not be used for any other purpose.
PARTS INFORMATION:
Parts required to complete this campaign should be ordered through regular channels, as follows:
Part Number Description Quantity/Vehicle ----------- --------------------------------- ---------------- 12534215 Gasket Kit, Upper Intake Manifold 1 12345493 Threadlocker Loctite 272 (Red) 3 ml
NOTICE: Threadlocker Loctite 272 (p/n 12345493) comes in 10 ml container and is sufficient to coat bolts for approximately 3 vehicles.
PARTS AND LABOUR CLAIM INFORMATION:
Credit for the campaign work performed will be paid upon receipt of a properly completed campaign claim card or DCS transmission in accordance with the following:
Time Repair Code Description Allowance ----------- ------------------------------------------------- ---------- 2A Replace Upper Intake Manifold Gaskets - C/K Truck 1.5 3A Replace Upper Intake Manifold Gaskets - P Truck 1.9
Time allowance includes 0.1 hour for dealer administrative detail associated with this campaign. Parts credit will be based on dealer net plus appropriate model year parts handling allowance.
Repair Codes 2A and 3A include $3.96 for 3ml of GM Threadlocker Loctite 272.
SERVICE PROCEDURE:
1. Note settings of all electrical devices and then disconnect negative battery cable.
2. Remove air intake assembly.
3. Remove throttle cable end from throttle body.
4. Remove throttle cable from bracket and move aside.
5. Remove left front and left rear wire harness brackets.
6. Remove right front and right rear wire harness brackets.
7. Remove ignition coil from intake manifold.
8. Remove purge and PCV hoses.
9. Remove EGR pipe from adapter on upper intake manifold.
10. Disconnect all electrical connectors on components attached to upper intake manifold.
11. Remove (8) upper intake manifold bolts.
12. Remove upper intake manifold.
13. Remove the upper intake manifold gaskets and clean sealing surfaces with scraper as needed. (Notice: use care when cleaning not to damage sealing surfaces with scrapers or other tools.)
14. Install new upper intake manifold gaskets from kit P/N 12534215 onto lower intake manifold.
15. Install upper intake manifold.
16. Coat the (8) upper intake manifold bolts a minimum of 8 lower threads of each bolt with Loctite 272 (GM P/N 12345493).
17. Install coated bolts in revised tightening sequence (see figure 1) to torque of 8 Nm (6 lb. ft.).
18. Retorque all bolts in sequence to 14 Nm (10 lb. ft.).
19. Connect all electrical connectors to components attached to upper intake manifold.
20. Install ignition coil to intake manifold.
21. Install right rear and front wire harness brackets.
22. Install left rear and front wire harness brackets.
23. Install EGR pipe to adapter.
24. Install purge and PCV hoses.
25. Install throttle cable to bracket.
26. Install throttle cable end to throttle body.
27. Install air intake assembly and torque clamps to 15 Nm (I 1 lb. ft.).
28. Connect negative battery cable. Start and run engine one minute to verify engine operation (no Malfunction Indicator Lamp illumination).
29. Reset all electrical devices as noted in step 1.
30. Install Campaign Identification Label.
INSTALLATION OF CAMPAIGN IDENTIFICATION LABEL
Clean surface of radiator upper mounting panel and apply a Campaign Identification Label. Make sure the correct campaign number is inserted on the label. This will indicate that the campaign has been completed.
General Motors of Canada 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 General Motors dealer for information on whether your vehicle may benefit from the information.
Customer Support Department General Motors of Canada Limited
General Motors of Canada Limited
July 1996
Dear General Motors Customer:
General Motors of Canada Limited has decided that CERTAIN 1996 Chevrolet and GMC C,K,P truck model vehicles equipped with 7.4L engines may exhibit a condition in which the upper intake manifold gaskets do not properly seal between the upper and lower intake manifolds. When this condition occurs, there may be unmetered air pulled into the upper intake manifold causing complaints of rough idle, hesitation, hissing noise, engine stalling and/or a Malfunction Indicator Light (MIL).
To prevent the possibility of this condition occurring, your dealer will replace the upper intake manifold gaskets and apply GM Threadlocker Loctite 272 to the upper manifold bolts.
This service will be provided for you at no charge.
Please contact your GM dealer as soon as possible to arrange a service date.
If parts are required, ask your dealer for details regarding their availability. If parts are not in stock, they can be ordered before scheduling your service date.
This letter identifies your vehicle. Presentation of this letter to your dealer will assist their Service personnel in completing the necessary correction to your vehicle in the shortest possible time.
We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.
Customer Support Departinent General Motors of Canada Limited
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those 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 a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
