Sam TII

Hey Guys,

I just picked up a '99 for dirt cheap with what I think is rod knock but it's a bit intermittent. The rod knock I've been around before has been really constant, any change in crankshaft speed caused the noise, so figured I'd ask to help pin it down.

Sometimes I get some noise on start up, sometimes I don't and it seems to only make noise in a specific rev range, about 2500-3500 RPM. Sometimes it will make the noise at higher revs but not always. I made a video of the sound, any thoughts?



Thanks,
Sam

gooflophaze

Video is private.

Sam TII

Fixed video, should be public now. Apparently private is the default when you upload from mobile (at least on my account).

shuiend

iTrader: (24)

That is correct about private video's. I have had to go back several times and make the change.

Sam TII

I found this video this morning on CR, seems like the same behavior, the guy said it turned out to be bad connecting rod bearings:



The car has a pretty nasty oil leak so I'm guessing it was just run a bit low at some point and the bearing went dry.

shuiend

iTrader: (24)

I can't really tell from your video. How long did the motor sit before running it? Does the noise go away after a few minutes? Could possibly be some lifter tick, but I doubtful of that.

Sam TII

The noise seems to get worse as the engine gets warmer--I'd expect it to get better with lifter tick.

The noise is intermittent on start up but is always present somewhere in the rev range, typically seems to live around 2000-3500 rpm though.

shuiend

iTrader: (24)

Then definitely does not sound like lifter tick then. I would plan on pulling the motor and taking it apart to figure out what exactly is wrong.

Sam TII

Yep that's on the list for this weekend, figured I'd ask before just in case.

BadGT

Lets us know what it is my votes on rod bearing

glade

iTrader: (2)

My .02. Bad thrust bearing, causing rod knock/slap. Had two personal 99 engines let go due to it, and seen approximately 5 more in person fail from it.

KMag

iTrader: (2)

That's not lifter tick. I hear it knocking at some point in the video. I'm going with rod or wrist pin.

KMag

HappyMiata

def knocking, Im 100% sure. I have had experiences of knocking motors, sounds like valves but its not. I had a 1992 supra did this to me, it wasn't bad but after 5km of driving it started to knock and clatter at the lower end then I just got it towed.