Okay hey guys I’ve made a post about this before but old account wouldn’t let me login so had to make a new one, anyhow I’ve have this knock or tap in my engine that I’ve been trying to figure out for the longest time, it started about a year ago & could barely hear it at all I would have to point it out to my friend because it was so quiet but gradually got louder over time it’s a consistent knock or tap not clunky or off rhythm it matches rpm,///when I first start the car on cold start it takes 1-2 mins for it to start tapping then if I turn off & restart the car than it starts tapping immediately, I’ve changed these parts -
This is a 3.400 v6
Egr
Knock sensor
Plugs&wires
All lifters
Injectors
Oil pump
Along with a few other odds and ends
time serts for all rocker arms
All new gaskets from the heads up
I’ve checked the block & everywhere else for cracks all good there flex plate is good it isn’t an exhaust leak, rod bearings seem to have a lil walk side to side to them but for the most part I think they might be okay. The knock or tap seems to get louder if your underneath but idk maybe just a echo effect I’m posting a link it’ll take you strait to my engine tapping & you guys can tell me what you think https://youtu.be/qhS3xyLGH7I
Also you can see im running it without the belt on so you can eliminate pulleys
Unfortunately its a rod knock, a very common problem with this particular V6 .
You can take off the head cover and see the rocker arms and bolts. On the bolts that are stripped use a 5/16 drill bit (says on the heli-coil pack) to drill out the bolt hole. Then use the tap for the heli-coil pack you purchased from your local auto shop, Use a M8 heli-coil and re-tap the hole. Place the heli-coil in the new hole and re-thread your bolts and rocker arm (Ensure you shop vac the mess out of the head and change your oil shortly after repairing).Hopefully that will take care of the problem
Reread your post brother…
I’ve already put time serts & helicoils in every hole above the head gasket this knock has nothing to do with stripped threads
Whew. New lifters? And timserts for the 12 rocker pedestals? You are determined. You know the I/E pushrods are different lengths. Hmm, I have done heads on 3 different 3.4’s lately and they are easy to work on. Disabling 1 cyl at a time makes no difference in knock?
Yea tell me about it lol I’ve put a lot of attention & money into it & to answer your question no it doesn’t make any difference each cylinder stays the same sound plugged or unplugged also yes I do know about the e/i pushrod length like I said this knock started gradually over a year