okay. i just dropped a b16a in my 91 teg. it ran fine at first but throwing a code 22 due to a wiring problem. with that fixed and no codes present i drove to see if vtec would crossover. it didnt. so i checked oil again. its full. now i can hear a slight knock when i first start the car. it seems like after the motor gets oil pressure it kinda drops off and goes silent. but when i would rev just a little (like to 2500-3000rpm) i could hear a knock from the bottom-end. i am saying its a rod knock. it seems very slight at the moment and i am not going to drive it anymore.

1) how much damage do you think has been caused?
2) could i just put new bearings in it and if doesnt knock or seize up i am good right?
3) do you think i will need the crank reground?

any opinions greatly appreciated.

 

You should be able to just change the bearings. Micropolishing the crank is nice too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rocket &raquo;</TD></TR><TR><TD CLASS="quote"> Micropolishing the crank is nice too.</TD></TR></TABLE>

yes but the local shop will charge more labor for pulling the crank out!

 

Cool. Just make sure the journal is clean of any possible bearing material stuck to it.

 

gernerally speaking when you spin a bearing (causing rod knock) you're going to need a new crank. If you get lucky, you'll have to have the crank worked over more than just a micro polish.

Anytime you have a rod knock that causes an audible noise above all the other engine noises, it's bad enough that it's going to damage the crank.

Think about it, you've displacing a bearing to the point that a rod end is bouncing around making an aweful racket. In my limited experience with Honda cranks and clearances, you aren't going to like the end result when you pull the crank out.

Time for a rebuild.

 

its pretty much on ly there on start up tho. is there any hope. it goes away once there is oil pressure.

 

Then you might not have "rod knock."

It could mearly be a loudly ticking valve. Try having your valves adjusted or looked at to see.

Rod knock is VERY noticable, and generally DOESN'T go away after warm up.
If there is enough movement to truely KNOCK against the crank, then just warming up isn't going to make it go away.

You actually have the most oil pressure registered when you first crank it. I'd start to look in your head first, since you say once it builds up some running time it tends to go away, the head is the last place to get oil (seeing as how it's at the top.)

Just something to think about before you go tearing everything apart.

Now, if you're REALLY certain that it's a rod, then take off the oil pan, drop the oil pickup and turn the crank to where you can get to one rod at a time. A knocking rod will be loose compared to the others.... and a lose rod, even a SLIGHT wiggle is your problem. Honda's run clearences way too tight to allow ANY mistakes.

 

not to hyjack your thread but i think i have similar symptoms...
coming from the engine bay i will begin to hear a knocking noise (randomly), i will rev up a bit and it seems to follow but then it will go away. i can't seem to find any contact anywhere inside the engine that it might be coming from?!?!!? Is it possible to have a knock but only sporadically?!?!
-Bryan-

 

it might just be quiet and not really bad at all yet. you may be able just put new bearings in.