Here is the deal. My 1990 190E is making a tapping sound from the top of the engine every now and then. The oil is changed on a regular base with the good stuff (Castrol).

Tapping Traits:
The tapping starts and stops on its own, some time over a month apart. The sound is not consistent, loud some times soft other times. The tapping usually last from 10 to 30 minutes when it happens. At speeds over 30 mph the tapping stops, but when I come to a stop it start again.

I know the engine has over 287,000 miles, but I wold like to keep it another 200,000.

Does any one have any ideal what it could be?

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2Boris
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90 Mercedes 190E 2. 6
98 Dodge Stratus
94 Jeep Grand Cherokee
84 Toyota 4 Runner
85 Cutlass Supreme
85 BMW 318i
80 Monte Carlo
77 BMW 320i
69 Chev Malibu

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