Mine has done the same thing -kinda reminds me it's time to change
the oil cuz the noise doesn't go away -
At 09:15 AM 6/28/2004, you wrote:
>I have a '00 QC 4.7L automatic which now has 70K
>highway miles on it. I'm used to the various knocking
>and tapping noises that have been part of life with
>this truck since it was new, BUT I now have a new
>noise to question! Everytime I start it up cold(first
>time of the day or after it's been sitting for a few
>hours)it taps for a solid minute or so. It sounds
>exactly like a hydraulic lifter on a push rod engine
>that has bled down. Like a push rod engine hydraulic
>lifter, the tapping goes away after a
>minute or so(after oil pressure builds?). Is this a
>common problem? Could it be that one of the tappets is
>bleeding down? Does the 4.7L engine even have tappets
>that can bleed down? I do have a background in
>mechanics, but I don't have much knowledge of the
>4.7L. Mainly because I haven't needed to learn about
>it. Any ideas? I hear a lot of horror stories about
>these engines. Thanks in advance!
>Al
>
>
>
>
>
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This archive was generated by hypermail 2b29 : Thu Jul 01 2004 - 00:15:18 EDT