>>I turn the engine on when is cool in the morning and turn it back off inmediately and the fan spins free for some time, but when the enginne is hot and i turn it off, the fan stops almost inmediately (1 or 2 turns before stop, I think). >>



The fan should not free-wheel when turning the engine off , even when cold.
And that is why I asked the last question of the post. If you decide to answer that , and if your answer is a YES, then the viscous is suspect.

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A Dalton