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Discussion Starter · #1 ·
I have a 2002 Impala LS with the 3.8 k vin engine 70000 Miles. Everything was running great till a few days ago. Now i have a loud squeal on start up and shut down and a quieter squeal while idling. If you pull the dip stick or slightly lift up the oil cap the sound goes away. I have been searching Threads for 3 hours now. I have changed the PVC valve and made sure the 2 orings were in good shape and not cut or deformed. Its not a pulley or water pump(ran it momentarily without a belt and replaced the water pump today). Took out the pcv valve and covered the intake port with my finger. Had a friend start the car. NO squeal! Pulled the oil cap still plenty of vacuum to be had. Thats how I came up with the excessive vacuum. Where else could vacuum come from since the PCV valve system has been bypassed. Thanks for the help. Tyler

P.S. Bought the car a week ago go figure.
 

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Discussion Starter · #3 ·
When you take off the MAP sensor and pull out the pcv valve and spring. There is the large hole that goes down to vent the crankcase and there is the smaller hole that is vacuum off of the manifold. I covered the small vacuum port and left the large hole vented to the atmosphere. So in theory there should be no vacuum on the crankcase. Please correct me if I'm wrong. I'm new to this 3800 series II stuff. I bought the car because the engines are suppose to be bullet proof.
 

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Everything you did sounds correct. The only one I've had torn down was supercharged so we'll have to wait for someone else.
 

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Same issue with my 2002 monte Carlo

Hi. I am just wondering if you ever receive any answer to your question or were able to resolve the issues you were having. My 3.8 02 monte is having the exact same problem and we can't seem to figure out why it is. Any help you can give on this problem would be greatly appreciated! We have replaced the entire intake and my PVC is working fine

Thanks so much

Theresa
 

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i had this issue once on my original engine... turned out that there's an o-ring for the pcv that likes to hide in the plenum, if you have replaced the plenum recently check to be sure you have all the o-rings (2 or 3 if i remember correctly)

if you haven't replaced the plenum recently i'd start by checking the pcv o-rings for damage due to age, and be sure they are seating correctly
 

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I know this is an old thread but just wanted to help anyone that comes across this thread as i did when my 2000 regal supercharged started making the same noise. On the supercharged engine the pcv valve is on the back of the supercharger and not the front of the intake manifold. I thought my supercharger bearings were going bad maybe. It is the pcv valve making the noise and I had the excessive crankcase vacuum issue. Replaced the pcv valve and did not solve the problem. I also had a code for a cylinder four misfire. Turns out the intake manifold gasket blew out between the cylinder four intake runner and the oil drain port. This is especially dangerous in the supercharged cars because your crankcase pressure will now mirror the intake manifold pressure. So when you are making boost it will blow your engine oil out the valve cover gaskets onto the exhaust manifolds and start a fire. Luckily i was pulling in my driveway and put the fire out before any damage resulted. Be careful out there
 
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