For a 1997 ZJ 4.0L, at what mileage should the timing chain be replaced? Aslo, what are the intervals to tighten the valves? I have 108K on my ZJ and was wondering if I needed to do anything into this regard before something goes wrong. Thanks.
10-12-2002 04:48 AM
I don't think there is a recommended replacement schedule for the timing chain. My haynes manual just says if there is more than 1/2 inch of chain deflection (measured by pushing the chain all the way to the left then all the way to the right) then replace the chain and sprockets.
I'm not sure what you mean by tighten the valves. Do you mean lapping the valves, or are you talking about doing something to the push rods or rockers?
10-16-2002 05:48 PM
With hydraulic lifters you should never have to adjust the valves -- I don't think there is any adjustment. With mechanical tappets like on my old '76 Dodge with the slant-six engine, you would adjust the valves periodically, but them were the old days. :)