For 1990-2009 cars only

Makes 🢒 Buick 🢒 2006 🢒 Terraza Ext. 🢒 Engine 🢒 Engine Controls - 3.9L 🢒 Base Engine Misfire with Abnormal Valve Train Noise

Base Engine Misfire with Abnormal Valve Train Noise for Buick Terraza Ext. 2006

Cause

Correction

Engine oil level overfull, causing aeration

Drain excess oil and adjust oil level to proper specification.

Worn or loose rocker arms--The rocker arm bearing end caps and/or needle bearings should intact within the rocker arm assembly.

Replace the valve rocker arms as required.

Worn or bent pushrods

Replace the pushrods.

Stuck valves--Carbon buildup on the valve stem can cause the valve not to close properly.

Repair or replace as required.

Excessively worn or mis-aligned timing chain

Replace the timing chain and sprockets as required.

Worn camshaft lobes

Replace the camshaft and valve lifters.

Sticking lifters

Replace as required.

Malfunctioning camshaft position actuator--Improper viscosity oil, contaminated oil, or a plugged or missing camshaft position actuator filter can cause the camshaft position actuator locking pin to malfunction.

•	Verify correct oil viscosity by changing the engine oil and oil filter and re-evaluating the concern.

•	Inspect for a missing or plugged camshaft position actuator filter.

•	If filter is missing, replace the filter, replace the camshaft position actuator, and change the engine oil and oil filter.

•	If filter is plugged, replace the filter, and change the engine oil and oil filter.

•	If no problem is found with the camshaft position actuator filter, replace the camshaft position actuator and change the engine oil and oil filter.