95 efi 351 whines at startup

This is a California truck. The whine sometimes continues for about 15-45 mins. Mostly during cold weather. I've listened with an open hood, and it
seems to be near the "smog pump." Very hard to tell the location.
Any help?
John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Its probally the smog pump.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
john opined in

had same on 85 e150 351, just before pump locked up
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
says...

The air pump probably has a diverter valve that dumps the air into the engine compartment until the engine is up to temp so that the catalyst will work. This unmuffled air will have a high pitched sound due to the vane pump.
The alternator will be charging heavily the first few minutes after starting, and will make more whine than usual.
And the power steering pump will make more noise than usual with cold, thick fluid.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.