Chrysler Repair: 3.3L valve noise: diagnosis and repair, tappet noise, noisy tappets

Question
I have a 98 Grand caravan with a 3.3l
102,000 miles, flex fuel. I have had minor valve ticking in one of the rear cylinders for some time, in the last week it has gotten very loud, what is the concern and what is the fix for the problem? I have kept oil changed and have tried some engine cleaners with no results. Thank you
Tom Raville

Answer
Hi Tom,
I have a couple of Chrysler manuals that discuss the diagnosis of valve train noise. Here is what is said:
"To determine source of valve train noise, operate engine at idle with cylinder head covers removed and listen for source of the nose.
Feel each valve spring or rocker arm to detect noisy tappet. The noisy tappet will cause the affected spring and/or rocker arm to vibrate or feel rough in operation.
Worn valve guides or cocked springs are sometimes mistaken for noisy tappets. If such is the case, noise may be dampened by applying side thrust on the valve spring. If noise is not appreciably reduced, it can be assumed the noise is in the tappet. Inspect the rocker arm push rod sockets and push rod ends for wear.
Valve tappet noise ranges from light noise to a heavy click. A light noise is usually caused by excessive leakdown around the unit plunger which will necessitate replacing the tappet, or by the plunger partially sticking in the tappet body cylinder. A heavy click is caused either by a tappet check valve not seating, or by foreign particles becoming wedged between the plunger and the tappet body, causing the plunger to stick in the down position. Thes heavy click will be accompanied by excessive clearance between the valve stem and rocker arm as valve closes. In either case, tappet assembly should be removed for inspection and cleaning."
There are then procedures described on how to do these various corrective actions. Also the Haynes manual for the '95-2000 shows how to do the valve train servicing.
If you are equipped with the tools and interest in doing this work yourself I think you could give it a try. It doesn't require taking off the cylinder head, so it is probably something the amateur can do. If you don't have access to a manual I would be glad to xerox copy and mail you the pages that apply. I would do this at copy cost (4 cents per page plus postage).
So feel free to let me know. If I am shown as maxed out, please respond via the "thank and evaluate" response tab at the bottom of this reply where the comments section would give you space to tell me your address.
Roland