3800 engine chirping

I have a 2001 Pontiac Grand Prix with 135,000 miles. It has the 3800 v6, no super charger. The motor has developed a chirping sound. The noise only starts after the engine is hot. At first I suspected a bad water pump
or some drive belt accessory but the noise is still there after I remove the serpentine belt. The noise sounds like a bad bearing. Is this likely to be a timing chain issue? What other part could cause this behavior? The oil has been changed at regular intervals and is dinosaur oil, not synthetic. Thanks for any help, Terry
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
terry wrote:

Here is an update. I took the oil cap off to see if I could hear the noise coming from the valve train. The cap had a high vacuum, and as soon as I removed the cap the noise went away. Seems to be a vacuum leak somewhere, not sure why it is causing the noise. Terry
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Was the pcv recently out or replaced, if so one of the o rings under the map sensor may be missing.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Shep wrote:

That was the problem...I bought the car used and have never had the PCV valve out. I have owned it for nearly two years and this problem only showed up a few weeks ago. Strange. Thanks, Terry
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Since it is heat related it has to be something expanding when it gets hot.
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.