Re: Gremlins knocking on cold start

[Heather & Jeff <hjr@buffnet.net>]

I've had a mysterious random knock on cold start-up and wonder if anybody 
has some insight.  It's on my '88 80q.  Ever since I bought it three 
years ago it's had noisy lifters that come and go.  However, about 6 
months ago, a new noise started.  On a cold start after sitting all 
night, it also has a slight random metallic knock.  Almost like a rod, 
but with no pattern.  Sometimes the knocks may be spaced two 
seconds apart (noisy rods usually have a constant tick tick tick beat)  
Does this for about 10-30 seconds, then its gone, till the engine has 
been stone cold for hours, and re-started.  

The curious thing: about a month ago I got adventurous and replaced the 
lifters, timing belt, and water pump.  No more noisy lifters! The random 
knock now gone too!?  However, as of yesterday, the random knock is back 
:-(.  (at least the lifters are still quiet :-)

Poking around under hood at cold start, it almost sounds like the noise 
is at the rear of the engine, the distributor maybe?  If so, why only at 
dead cold?  And why did it go on a month's hiatus after above said work?

PS. A new sound developed after the lifter job.  A whirring sound, only 
at certain rpm's (slightly at idle, very pronounced at exactly 1700 rpm, 
no noise at any other rpm)  Suspect alternator or PS pump.  Any other 
ideas?

Jeff

'88 80q