Well i just replaced the rings, and bearings in my d16a6, put a rebuilt y8 head, mani, and headers on my car, everthing fresh but the one problem im having now is that there is a knocking noise coming from the head. It only does it after 3000 rpms sometimes, and it gets louder when the vtec kicks and sounds like a rod bearing, but i used a stethascope thingy on it and the noise is for sure coming from the head and not the lower block. Anyone have any ideas? i thought maybe the head shop i got head from didnt line bore the cam journals and there is some play in the cam, so at 3000 rpms, it starts to wobble a little, might sound dumb but only idea i have. Help

Oh and its not the valves i adjusted them perfectly and plus a loose valve sounds different than this, this is a low tone knock.

 

did you adjust them on a cold .... like dead cold engine?
Edit: hows the PG7? working out good?

 

ya i adjusted them cold like before i started the engine for the first time, then again the next day, and the pg7 is working good, is just everything else that is going to give me a nervous breakdown, lol.

 

i'm not really sure what would make a lower piched noise, are you still breaking in the motor? if so change you oil with new filter (non synthic) and cut open your old filter and look for metal shavings, if alot are their then it's your block, not sure about the head tho, they could have left a bolt loose, sorry cant help you past that without hearing it in person

 

5 bucks says that one of his pistons is backwards...seen it happen.

 

Well me and my dad didnt put any of them in backwards, hes been building engines for 20 years, all the arrows were pointing toward the crank pully, and each one was labeled 1, 2 , 3, 4 and put back exactly the same. Hes stumped too, sounds like a rod bearing but coming from head not block, kinda strange.

 

bump for a good buyer hope you figure this out dude

 

its the bearing, you just don't want to believe it. i had the same problem. i though it was coming from the head then when i torn it apart the bearing and the rings were pretty much gone.

heres a question for you. Does the noise get louder as you drive at a steady high RPM and does the noise change as you release the gas pedal at high RPM??? also does the noise sound like a grinding noise.

 

Well there was no noise coming from the bearings before i tore motor apart, i put new bearing, and rings, and put on the y8 head i recieved and got it running. I had 3 friends of my dads off road club listen to it and they said it is coming from the head, its coming from up top not down below. If you look at the cam with a flashlight it is all scratched up on the runners. Im calling the place i got the head from, and returning it for another one, then if the problem prosists then i guess it is a bearing, but like i said its for sure 95% coming from up top on the passenger side of the head, and a rod would be knocking on the low end of block. Remember i used a stethascope and listened up top and down low, and its coming from uptop. Thanks for all the help you guys have giving. Oh and the noise dont kick in until 3000 rpms, and it gets louder when the vtec kick in, once vtec kick off it gets almost to wear you cant hear it, and it is knocking not grinding.