Re: Tapping @ startup + hesitation = bad lifter?

[zm@mhcnet.att.com (Zafer Mehmood [209])]

Chris,
	Your theory does seem plausible, especially if one of the hydraulic
lifters is leaky and allowing all the oil to drain out overnight. So the
lifter wouldn't work right until the oil has been pumped back into it again.
I presume you've read the thread here previously that the use of Audi oil
filter with the anti-drain back valve helps keep the oil in the passage ways
and reduce tapping noise at initial startup. Considering that your car is
a '93 and probably is dealer serviced under the Audi Advantage program,
you are using Audi oil filters anyway. Since your car is probably still under
warranty, tell the dealer about the hesitation at the 2500-3000 rpm and
see if he'll fix it under warranty. Stressing the *hesitation* is important
since the dealer will usually say that some lifter noise at initial startup
is normal, which it is.

Disclaimer: Most of my comments are based on the 5 cyl. engine and I am
not familiar with the 2.8 V6 that is in the newer Audis; but the principles
are the same as far as hydraulic lifters, etc.

Zafer


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Zafer Mehmood				   AT&T Bell Laboratories
zm@mhcnet.att.com			   Murray Hill, NJ