Hello- Any suggestions to this?
Over the weekend, I replaced my upper intake and gasket because of gasket failure. Much to my shigrin, a noise appeared after the engine ran for approx 30 min. The noise sounds like a loud screech; the engine does not make the noise under load at high rpm or when the engine is cold. As far as I can tell, the noise appears at idle after the engine warms. Not knowing what to do, I tried pulling out the oil dipstick alittle and BOOM noise goes away... stick the dipstick back in, noise comes back.. What am i missing here??All my connecions have been double checked- thanks for any help you might give

Any chance of posting a video of the noise? Only thing that comes to mind right now is your PCV valve.

Sounds like a manifold vacuum issue.....when you replaced the intake did you make sure you put the o ring on the pcv valve and seat it correctly it can be difficult

I'm thinking the same thing, PCV. The PCV valve essentially ventilates crankshaft pressure, and if you pull the dipstick, you're essentially giving the car another way to ventilate that pressure.

Try removing the oil filler cap and see if it does the same thing. If so, PCV valve.

Thank you,, thank you, thank you!! You guys are awesome. Mind you, like most, this is not my first time under the hood of a vehicle- however, checked the NEW PCV valve- no movement. Replaced the NEW one with another NEW one- problem solved- no more noise. Thanks again for the responses

Cool I'm glad you found the problem...enjoy your ride now!

Seconded. And a belated welcome to GM Forum!

Don't be shy: go say hello in the "Introductions for new members" section.