High Oil Consumption After Installation of Goodwrench Remanufactured Engine
| Subject: | High Oil Consumption After Installation of Goodwrench Remanufactured Engine (Diagnostic Checks) |
| Models: | 1985 Chevrolet Impala |
| 1985-88 Chevrolet Caprice, Monte Carlo |
| 1985-86 Pontiac Parisienne |
| 1987 Pontiac Grand Prix |
| 1985-87 Chevrolet El Camino |
| 1985-87 GMC Caballero |
| 1985-86 Chevrolet and GMC C/K Models |
| 1985-95 Chevrolet and GMC G, M Vans |
| 1987 Chevrolet and GMC R/V Models |
| 1988-95 Chevrolet and GMC C/K, S/T Models |
| 1990-95 Chevrolet and GMC L Van |
| 1991-94 Oldsmobile Bravada |
| with 4.3L V6 Engine (VINs N, W, Z -- RPOs LB1, L35, LB4) |
Condition
Some owners may comment on high oil consumption after a GM Goodwrench remanufactured 4.3L V6 engine is installed. High oil consumption would be defined as more than 2 quarts of oil in 2,000 miles (2 liters in 3,200 km).
Cause
Although there are several possible causes for high oil consumption, the following sources have been found to occur in remanufactured 4.3L V6 engines. These following sources may occur independently, or in combination, and can be repaired without removing the engine.
| • | Missing valve stem O-ring seals. If one seal is observed missing, it is safe to assume that all seals will be missing from both cylinder heads. |
| • | Thread sealant not applied to intake valve rocker arm studs (oil wicks past threads into cylinder head intake runners). If thread sealer is observed missing from one stud, it is safe to assume that sealer was not applied to any of the studs in both cylinder heads. |
| • | Thread sealant not applied to intake manifold bolts (1992-1995 VIN W -- RPO L35 ONLY). Four of the intake manifold attaching bolts reside inside the plenum which exposes them to manifold vacuum. Engine oil wicks from the engine valley, past the bolt threads, and into the plenum where it is ingested into the intake runners and cylinders. |
Correction
Check the listed possible sources for high oil consumption concern BEFORE replacing the engine assembly.
A. Missing Valve Stem O-Ring Seal -- All Applications.
Use published service information to determine if valve stem O-ring seals are present. The leak test procedure utilizing the Kent-Moore J 23738 A should be used. If a leak is detected, and it is discovered that the seal is missing, the technician can assume that all twelve (12) of the intake and exhaust valve stem O-ring seals will be missing and should be replaced with P/N 10214034. If a leak is detected and the O-ring seal is present, it should be replaced with P/N 10214034, and the remainder of the intake valve stem O-rings seals should also be leak-checked (due to the rotators, exhaust valve stem O-ring seals can not be checked using this procedure).
B. Thread Sealer Not Applied to Rocker Arm Stud -- All Applications with Screw-In Rocker Arm Studs.
Use published service information to remove one (1) rocker arm stud and inspect for the presence of thread sealer on the lower threads that engage the cylinder head. If the presence of thread sealer is not observed, it may be assumed that all twelve (12) rocker arm studs need to be removed and thread sealer (P/N 12346004) applied to the lower threads. Use published service information to re-install rocker arm studs and tighten to published torque specification.
C. Thread Sealer Not Applied to Intake Manifold Bolts -- 1992-1995 RPO L35 Only.
Use published service information to remove the intake manifold upper plenum and remove one (1) intake manifold bolt. Inspect the bolt threads for the presence of thread sealer. If the presence of thread sealer is observed, apply thread sealer P/N 12346004 to the bolt threads. Re-install bolt and tighten to published torque specification. If no thread sealer is observed, repeat thread sealer application, one (1) at a time, to the remaining three (3) intake manifold bolts residing inside the plenum. The tops of these intake manifold bolts are exposed to manifold vacuum, and without sealer on the threads, provide a leak path for oil to traverse from the lifter valley to the intake air stream and be ingested in the engine.
Parts Information
Part Number | Description |
|---|---|
10214034 | O-ring, Valve Stem Seal |
12346004 | Sealant, Thread |
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J0224 | Manifold and/or Gasket, Intake lower - R&R or Replace | Use Published Labor Time |
J0380 J0381 | Stud, Rocker Arm - Replace - Right Bank Left Bank | |
J0540 J0541 J0547 | Spring, Cap and/or Seal, Valve - Replace Right Bank Left Bank Both Banks |
