Engine - Valve Train Noise/Miss/Rough Idle
87olds2SUBJECT VALVE TRAIN NOISE, ENGINE MISS, ROUGH NUMBER: 87-T-33
IDLE, OR OIL CONSUMPTION DUE TO CYLINDER HEAD EXHAUST VALVE GUIDE WEAR
DATE: July 10, 1987
MODELS/YEARS 1987 CUTLASS CIERA AND CALAIS WITH
2.5L L4 ENGINE (VIN CODES R, U) SECTION: 6A
Some 1987 vehicles with 2.5L L-4 engine may experience worn exhaust valve guides in the cylinder head. An engine with this condition may exhibit valve train noise, missing and a rough idle. This condition could be caused by puddled chrome on the exhaust valve stems, which results in a rough surface and accelerates wear.
If an engine exhibits these symptoms, measure valve stem-to-guide clearance of all exhaust valves. If one or more exhaust valve guides in the cylinder head are worn to the point where clearance is .004" to .006", ream all exhaust valve guides to the appropriate oversize diameter, recondition all exhaust valve seats, and replace all four exhaust valves with the correct oversize valves as described in the service manual. If oversize valves are not available, replace the cylinder head and all four exhaust valves with standard size valves.
If one or more exhaust valve guides are worn enough that stem-to-guide clearance is .007" or greater, replace the cylinder head and all four exhaust valves with standard size valves.
Exhaust Valve Part Numbers
Part Number 10044612 Standard Size Stem
Part Number 10044613 .003" Oversize Stem
Part Number 10104418 .005" Oversize Stem
Cylinder Head Part Numbers
Part Number 10049099 Calais with L68
Part Number 10049100 Cutlass Ciera with LR8
All engines have a build sequence number on a large bar code sticker located on the exhaust manifold side of the cylinder block above the oil pan rail. Engines having numbers higher than the following, which appear on the sticker, should not exhibit premature exhaust valve guide wear:
Sticker Number
Cutlass Ciera 0378434
Calais 6188498
Use applicable Labor Time and Operation Number.