QuestionRoland,
I know my 3.8L has a timing chain rather than a timing belt. It seems that I have read that it is recommended that the timing chain be replaced at 150k miles. But I have read other things that state it does not really need to be changed. Our van is a mommy mobile and has not been used for towing or hilly areas, or driven hard. It has 160k miles now and appears to run fine. In your opinion, do I need to replace my chain as routine maintenance like other belt driven engines? Thank you in advance. I have called on you before and have appreciated your help.
-Preston in Walla Walla WA
AnswerMEASURING TIMING CHAIN FOR STRETCH
Place a scale next to timing chain so that any movement of chain may be measured.
Place a torque wrench and socket on camshaft sprocket attaching bolt and apply torque in direction of crankshaft rotation to take up slack; 41 N·m (30 ft. lb.) with cylinder head installed or 20 N·m (15 ft. lb.) with cylinder heads removed. With a torque applied to the camshaft sprocket bolt, crankshaft should not be permitted to move. It may be necessary to block crankshaft to prevent rotation.
Holding a scale even, with dimension reading as shown Measuring Timing Chain Wear and Stretch , along edge of chain links. Apply torque in the reverse direction to 41 N·m (30 ft. lbs.) with cylinder heads installed, or 20 N·m (15 ft. lbs.) with cylinder heads removed. Check amount of chain movement.
Install a new timing chain, if its movement exceeds 3.175 mm (1/8 inch)
If chain is not satisfactory, refer to Timing Chain Removal and Installation in this section
