New member. Knocking engine between 2.5K-3.5K rpm

[99_VX]

I did fill up from chevron. I was wondering if seafoam treatment made the knock louder. I have used seafoam before and it has always smoked after getting it in the vac line/intake but it did not this time. Anyone had a bad experience with seafoam?

[circmand]

while running it to empty you can add octane boost to help a bit. Or if you have a track or airfield around you might be able to find some 110 octane which will blend and raise the octane level.

[MSHardeman]

Stupid question, maybe, but are you sure it's the engine knocking? I get what sounds like a valve clatter under load also, but aren't our cars supposed to have all kinds of fancy knock sensors and such to prevent knocking? I think my noise might actually be one of the heat sheilds under the VX rattling around when the engine is under load and vibrating a bit. I haven't gone down the road with my head hanging out of the window to try and pinpoint the noise yet, so I could just be talking smack.

[99_VX]

I can hear the knock when parked and revving the engine by hand. My heatshield used to make some noise but I took care of that. I am pretty sure it is coming from the engine. That said the heatshield was making a terrible noise before I secured it. Has anyone done a valve job on the VX? I thought we had hydraulic lifters but read somewhere otherwise.
On a better not I am reupholstering my front seats with european leather .
Did you guys know the back seats are vinyl?

I really appreciate all inputs.

[Gussie2000]

Make sure the belt tensioner is in good conditions,usually causes a knocking noise when it goes bad.

My VX has a knocking,but is valve related and probably rebuild the entire engine next year

[mantis465]

I thought we had hydraulic lifters but read somewhere otherwise.

vx has over head cams. which means no lifters solid or hydraulic, cam is directly over valves so no need for push rods or lifters.

and yes they can be adjusted but you need shims to adjust them