[PONTIACGUY99]

I have a Grand Prix GTP with an engine knock. It seems to be at valve train speed. It increases under load. Especially up hill.
Does anyone have any ideas what it may be.

 

[Slideways]

Are you sure it's not pre-ignition knock? What octane are you using?

 

[PONTIACGUY99]

I'm sure it's not. I use premium and it still does it. It also has been increasing in loudness.

 

[Smaart Aas Saabr]

maybe a dead lifter

 

[a_v_s]

maybe a dead lifter

Could also be a bad seal. The 3800 Series-I in my dad's old buick did that. At the time he was too cheap to fix it correctly, so he ran 20w-50 oil which seemed to "fix" it. Basically a bad seal was causing too much oil to get by or something, resulting in lower than normal oil pressure. Knocking was valvetrain chatter or something like that...

On my old small-block Chevy V8, I had a similar knock when I had a dead lifter... I just pulled the valve covers, and found right away which lifter was dead.

 

[Johnny P]

maybe a dead lifter

That's my bet. We've done a couple on 3800's here for a noise.

 

[F14CRAZY]

Just to clarify, do you have the 3.4L DOHC or the 3800 Series II Supercharged engine?