Engine - Timing Chain Rattle When First Started
90pontiac16Bulletin Number: 90-6-37
Reference Number: 076102
Publish Date: 8/90
Subject: TIMING CHAIN RATTLE TYPE NOISE FROM ENGINE ON START UP - (INSTALL PF1225 ENGINE OIL FILTER)
Monels
Affected: 1987-90 GRAND AM AND GRAND PRIX MODELS WITH 2.3L
Some owners of 1987-90 Grand Am and Grand Prix models equipped with a 2.3L engine may comment about a rattle type noise from the engine when the vehicle is first started. This noise will then usually disappear within a few seconds.
This condition may be the result of oil in the engine oil filter draining back into the crankcase after the engine has been shut off. As a result, engine oil pressure sufficient to fully extend the timing chain tensioner plunger to properly tension the timing chain may be delayed a few seconds when the engine is started. While there is no adverse affect on component durability or performance, timing chain noise may occur for this brief period of time.
To minimize oil filter drain back and timing chain start up rattle noise, it is recommended that an AC Rochester, PF1225 oil filter be installed. This filter exhibits excellent anti-drain back characteristics and is now being used in production. The PF1225 is also the recommended service replacement oil filter for this engine.