Balancer shaft effects
Sorry, I'm new to blogging. The issue is after rebuilding the motor I have a vibration at higher RPM and load throaty sound at idle (only in the cabin) and at higher RPMs which I think are cause by the vibration. The throaty sound is similar to an exhaust manifold issue but I ruled that out. I believe the vibration is from un-timed balancer shafts, or something else I screwed up in the rebuild. I need to understand the effects of un-timed balancing shafts.
For background, I acquired a 2004 CRV, AWD, AT 2.4L from a friend that lost timing and blew the engine. The damage was sever: the 2 intake valves were smashed, the valve seats in the head were ruined beyond repair,the piston was canted in the cylinder with a hole in it and the side skirts were smashed, and the connecting rod was bent slightly preventing the crank from turning a whole revolution. I found bits of metal in the intake manifold, oil pan, oil pump, and the oil screens.
I rebuilt the motor in my garage using a combination of aftermarket parts, junk yard head, and a few honda parts. I replaced all bearings (main/connecting), pistons/rings, valves, one connecting rod, cylinder head, timing kit, and a variety of sensors; honed the cylinders, and changed the trans fluid. I lapped the valves on the junk yard head, set the rocker arm gaps to spec, and measured all the specs I could and they were good. I did not take anything to a professional for refurbishing or balancing.
Slapped it all back together and it runs. The only issue is the previously described sound/vibration. I took it to a muffler shop and he said the exhaust was fine but the noise sounds like its coming from the transmission. He said it was down a quart and when you change the trany fluid or are low on fluid, can some times cause vibration. I added a quart and no change.
After more research I realized what the balancing shafts are! I didn't set any timing when installing; I just installed it at whatever random position. So I attempted to set the balancing shaft timing and the vibration is much better, but still present. Upon further research I don't think I set the timing correctly.
Does anyone have experience with setting the balancer shafts and the effects of improper timing or just removing all together. I plan to try once to set the balancer timing. Thanks for ANY thoughts.