Engine - Miss Above 3500 RPM Diagnosis
90buick11 Bulletin 90-6-8Date Sept. '90
Ref. No. 90-178-6
Corp. Ref. No. 006105
SUBJECT: ENGINE MISS ABOVE 3500 RPM'S ON VEHICLES EQUIPPED WITH 3300/3800 V6 ENGINES (REPLACE CAMSHAFT)
MODELS AFFECTED: ALL 1989-90 VEHICLES EQUIPPED WITH 3300/3800 V6 ENGINES
An engine miss above 3500 rpm's, often without an accompanying valve train noise, could be caused by a broken camshaft lobe. If normal diagnostics fail to pinpoint the source of the miss, and the miss is isolated to the number 2 cylinder, inspect the 4th lobe back from the front of the camshaft for being broken.