It takes some force.just wiggle and pull.I would also change the dex-cool antifreeze while your at it and replace with green anti freeze .Dex-cool is junk. good luck
www.3800Pro.com is a great site for 3.8 info.
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SEVEN UPS 2.0 TAKING THE THIRD DEGREE ONE STEP FURTHER
2016 1/8 MILE 7.0 @ 100 MPH 406 B&M MINI BLOWER