16790-ZY1-023 Honda CHAMBER, FUEL (Honda Code 8820326).

This Program must be administered as soon as possible. When reporting the repair, use "PI30024" as the Part number and "7751" as the Group Number, "56" as the Warranty Claim Description Code and "T" as the SIMS Description Code. Exception: If the repair is done after failure, use "PI30024" as the Part Number, "7751" as the Group Number, "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.
Completion Date
December 31, 2000Termination Date
June 30, 2001Problem
Some 3500 Diesel Engines have been built with cylinder heads that may have the water outlet blocked by casting flash. The blockage may cause the cylinder head to overheat and may cause a valve to seize or at worst, a piston to seize.
Affected Product
Model & Identification Number
3508 (3LS221-223, 3PS193-196, 95Y1118-1119, 96Y1958-1961, 97Y732, 23Z7604, 23Z7612-7620, 23Z7624, 69Z863-864)
3508B (4GM514-526, 4GM528-534, 4GM536, 7SM273-290, 5PS255, 2HW134-135, 3DM167, 3DM170, 2BM143-144)
3512 (6PM46-47, 3MS217-220, 3MS222, 49Y950-952, 50Y1704-1705, 50Y1707, 50Y1709, 24Z9497-9500, 24Z9502, 24Z9505-9507, 24Z9510, 24Z9513, 24Z9517-9519, 24Z9522-9528, 24Z9536, 24Z9540-9541, 24Z9543, 65Z963-970, 66Z890-891, 67Z1882)
3512B (7HM210-213, 8RM455-457, 4TN258-259, 4TN266, 4TN269, 6WN459-470, 6WN472-474, 2GW239, 3ZW167-168, 3ZW170-174, 4AW380-383, 5AW78-80)
3516 (5SJ716-717, 5SJ722, 7KM64-71, 3SS323, 25Z6701, 25Z6714, 25Z6726-6728, 25Z6732-6733, 25Z6737-6738, 25Z6751, 25Z6756, 72Z555-556)
3516B (6HN559-564, 6HN567-579, 6HN581, 6HN583-585, 6HN588-596, 7RN1019-1021, 7RN1023, 7RN1025-1039, 7RN1041-1045, 7RN1048-1052, 7RN1054-1060, 7RN1062-1064, 7RN1068, 7RN1070-1072, 7RN1074, 7RN1077, 7RN1082, 7RN1085, 8CN172-173, 8KN391, 73Z932-934)
777D (AGC127-128, AGC130-155)
793C (4GZ257)
New or Spare Engines
3508B (2GR2284, 2313)
3516 EUI (2PK1607)
3516B (7TR970, 971)
Parts Needed
Quantities marked with an '*' are one per cylinder.
* - 8N4524 GASKET* - 6V9769 SEAL-O RING1 - 9X6772 STRAP-CABLE* - 1272176 SEAL1 piece of " bar or round stock, 11 to 15 inches in length, is also needed.
If Water Coolant Manifold Is Removed:
Some engine arrangements may require removal of the coolant manifold in order to access the 8N-7639 Elbows. This is due to the amount of peripheral iron located around the cylinder heads. If you are unfamiliar with the engine that you are working on, take the parts listed below as a precaution. The parts listed below will be needed only if the coolant manifolds are removed.
As needed
4 - 8N-1269 Gasket6 - 1W-8545 Gasket2 - 2W-0752 Gasket4 - 5P-9890 Seal O Ring If Coolant Passage Cannot be Unblocked
Some cylinder heads may have blockage that cannot be removed. In those cases, the cylinder head will need to be replaced. The parts listed below will be needed only if a cylinder head is replaced.
1 - 0R9775 Cylinder Head (MUI - Non Shot Peened)or1 - 0R9777 Cylinder Head (MUI & EUI Shot Peened)or1 - 0R9472 Cylinder Head ("B" Series)4 - 1261112 Seal-Water4 - 1261113 Seal-Water1 - 1445692 Gasket-Plate1 - 1106991 Gasket-Head2 - 5P0840 Seal-O-RingsAction Required
See the attached Rework Procedure.
Owner Notification
U.S. and Canadian owners will receive the attached Owner Notification.
Service Claim Allowances
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.
Attach.(1-Owner Notification)(2-Rework Procedure)Copy Of Owner Notification For U.S. And Canadian Owners
Rework Procedure
Rework Procedure Verification of Manufacturing Date
Cylinder heads with manufactured dates between 12/10/99 and 1/31/00 are suspect. Any cylinder heads with manufactured dates before 12/9/99 or after 2/1/00 are not effected by the blockage. The engines listed above may or may not contain the suspect heads. To verify if heads need to be inspected for blockage, check the manufacturing date stamped on the left-hand front corner of each cylinder head. See Illustration 1 for location of the manufacturing date. The manufacturing date is in the format of MM/DD/YY.
Illustration 1. Only cylinder heads stamped with manufactured dates between 12/10/99 and 1/31/00 need to be inspected for blockage.
Inspection for blockage
The engine coolant must be drained below the level of the cylinder heads before the 8N-7639 Elbows should be removed.
Remove the 8N-7639 Elbow from each suspect cylinder head. The 8N-7639 Elbow transports coolant from the cylinder head to the coolant manifold. The 8N-7639 elbow is located on the left-hand rear of the cylinder head. See Illustrations 2 & 3 for location of the 8N-7639 Elbow.
Illustration 2.
Illustration 3.To remove the 8N-7639 Elbow, remove the two 1B-7182 bolts (" x 1 ") that bolt the 8N-7639 Elbow to the cylinder head. Next, Remove the two 1B-7182 bolts (" x 1 ") that bolt the 2W-3146 Flange to the Coolant manifold. The 8N-7639 Elbow should slide out from underneath the water manifold.
Some engine arrangements may require removal of the coolant manifold in order to access the 8N-7639 Elbows. This is due to the amount of peripheral iron located around the cylinder heads. If this removal is required, be sure to use the new gaskets listed in the "as needed" parts list when the manifold is reinstalled.
To inspect for blockage in the cylinder head, use a stiff but flexible piece of plastic such as a 9X-6772 Strap-Cable to insert into the coolant outlet passage on the cylinder head. See Illustration 4 for locations to check for blockage. There are two passages in the coolant passageway inside the cylinder head. Make sure both passages are clear of blockage.
Illustration 4.If blockage is found, use a " piece of bar stock or round stock shaped into an "L" with a pointed tip. See Illustration 5. Using the modified stock, knock the blockage loose. Lightly tap the stock with a hammer if the blockage will not loosen by hand. Once the blockage has been removed, use a magnet or a vacuum to remove the pieces of the blockage from the coolant passage.
If the blockage cannot be removed, the cylinder head must be replaced. See the "Parts Needed" section for the required replacement parts.
Illustration 5.Reinstall the 2W-3146 Flange with a new 8N-4524 gasket and the 8N-7639 Elbow with new 127-2176 Seal. Install the four 1B-7182 Bolts and torque to 25 N m.
If the coolant manifolds were removed, reinstall the manifolds with new the seals and gaskets listed in the "As Needed" parts list. Torque on the coolant manifolds bolts is 47 N m.
Refill the engine with coolant and check for leaks.