Smog/air pump noise (???)
Thread Starter
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
and that seemed to lessen the 'noise', but my hearing is suspect, so
I really don't know if there was a change.
Advanced
Joined: Jul 2013
Posts: 67
Likes: 0
From: Massachusetts
I can't find the knock. It appears after about 5-10mins of startup, once it gets warm. I've put a long screwdriver to the ear and a long hose but I can't pinpoint the knock location. I've checked/tightened all the mounts and brackets and checked the all the pulley bolts for tightness. It's not a heat shield or fuel hammering. Must be a bad bearing; alternator or air pump but I can't pinpoint it. Again, with the belt off, no knock.
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Joined: Jul 2013
Posts: 67
Likes: 0
From: Massachusetts
New smog pump and new alternator didn't cure the knock. They were old and didn't spin 100% smoothly so I took a chance. Fail. Now I need to somehow run a shorter belt so I can bypass the remaining accessories one by one to rule them out: a/c compressor, PS pump, water pump. They spin smoothly and true by hand but maybe the tension and speed of the belt affects them.
Again, start without the belt, no knock and tensioner is brand new. Knock occurs a few minutes after starting.
Again, start without the belt, no knock and tensioner is brand new. Knock occurs a few minutes after starting.
