Ok so I recently had my motor professionally rebuilt. Had the head sent out to a machine shop to run pressure test, have it hot tanked, and have all of the parts inspected and checked. I had new pistons put on my original rods and replaced the connecting rod bearings. My car makes a knocking noise at low throttle acceleration. It sounds like a rod knock but how can it be if the bearings were replaced with new bearings. I have seen posts where this can be possibly caused by an LMA. How can I be sure of this? I am running 98 itr cams, valves, inner/outer springs, and retainers. Please help me out. I am pretty much ready to throw the towel in on this bucket of **** and buy a b18b1 or b18c1 bottom end and call it a day.

 

well, is it comming from the bottom or top of the engine?

 

I haven't gotten under the car and listened while it was running. It sounds like the top. My mechanic says it is the bottom end but I am skeptical considering we rebuilt the bottom end already.

 

Would like some more input plz.

 

You can try using a stethoscope to isolate the noise, or if you don't have one sometimes you can just put one end of a length of vacuum hose to your ear and move the other end around on your motor to generally locate a sound. Just an idea

 

what kind of pistons were put in

 

Rod = knock (deep, loud, extremely noticable)

LMA = tick/slap.. sounds like a car in need of a valve adjustment.

Hope that helps, and i hope you don't have a rod knock.

 

Can the LMA be fairly loud? Does it get faster as the engine spins? The thing is I can't see how I can have a rod knock when the connecting rod bearings were replaced and I still have the noise (noise was there before and still there after)

 

The noise tend to be at its loudest at approx 2500 rpm. Seems to be coming from the valvetrain.

 

since the bearings were replaced and the noise was there before and is still making it, its hard to believe that thats it.im leaning towards lma's

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sinatra &raquo;</TD></TR><TR><TD CLASS="quote">Can the LMA be fairly loud? Does it get faster as the engine spins? The thing is I can't see how I can have a rod knock when the connecting rod bearings were replaced and I still have the noise (noise was there before and still there after)</TD></TR></TABLE>

Yes it can, yes it does get faster as rpm's climb.