well me and 99B16si, may have come up with my tapping problem, has anyone ever had a problem with a "lost motion assembly" getting stuck or going bad, i know you can pullem out and see if they compress and spring back, but its a good amount of work, anyone else ever have this problem


it would sound logical that this could be my problem, cause it sounds like it is at the bottom of the head, but not in the bottom end, and it goes away if you rev it up.

 

Easy to check but most likely not the cause. Remove the valve cover and press down on the vtec rocker arm for each cylinder when it is at tdc. It should move down with slight resistance from the spring tension and then come back up when you release it.

 

If your LMA's are bad:
Compress the mid rocker arm on each set of arms.
It should compress fully & operate smoothly through its full stroke.
If you feel abnormal function replace the LMA.
(They are not cheap) $30 each i believe.

 

personally i cant think of anything else it would be. granted i only looked at it for a couple mins but whatever it is making that noise its nothing obvious. only does it at idle adn as soon as the rpms increase just a hair it goes away. almost sounds like a really loud injector, which could also be a culprit but i doubt it

 

thanks guys

 

Would this be the same for a z6, i just got my engine running good as shit, I walk all over ls eg's and crx's, but then two days later I started hearing a knock at around 2-3k so i pulled the motor out in fear of spinning a bearing or throwing a rod. Im not sure on what the knock is.Its dose sound more like a rods knock then a tapping. I just dont know why it would all of a sudden start making this noise, I guess high miles.

 

i just havent ever experienced one go bad, and was wondering if anyone had this problem at all?

 

A friend of a friend of mine had one go bad & thought it was a bottom end issue & cross threaded a head stud... Who knows how but he did.

Its hard to figure out if you have bad lma's because no one usually suspects an lma

 

Im gonna take a look at it thisweekend , I need to get some bolts to so i can put the engine on the stand. If it is a small rod knock that was caught early ,do you think the crank will need to be turned or can you just put new bearings in it? Im doing a complete rebuild with pistons, rods, all new bearings and seals. Im building the motor for boost so I dont wanna cut any corners you know what i mean.