My car is making this noise, does anyone have an idea of what it could be? This video is taken from under the car, it’s much more audible down there. The sound isn’t constant either, it goes away and comes back
It sounds like a rod knock.
I bought my 1st equinox with a good rattle/knock. And bad headgaskets. I made a mistake and switched 1 intake pushrod with a shorter exh pushrod. I got a definite knock when I started it. The 3.4 has pedestal rockers and it is known to pull the rocker stud out of head. A Grand Prix might have a 3.4 but probably a 3.8.
yup I have the 3.8 series iii L26
From what I’ve read it shouldn’t be a rod knock because it seems to go away as the engine warms up, I’ve been told a rod knock will stay the same/ only get worse? I’m not well versed in any of this. Any thoughts?
If the noise is diminished as the engine warms up, then it could just be piston slap.