Name That Noise, Win my Undying Gratitude!

[Kujo II]

http://www.youtube.com/watch?v=4rLZTxhFIgE

Here's a list of what it's not:

It's not the timing chains, all the guides are good and no slack or play in the chains, replaced 35k miles ago.

It's not valve lash, I checked clearance with a feeler gauge, all the valves were in spec.

It's not a rod, I pulled the pan, bearings look good, and I drove it 80 miles on the I-state after it started (figured I had a spare engine anyways, so...)

It sounds like it's in the top end, but....

Any help will increase your awesomeness to unprecedented levels

EDIT: Sorry, the video is dark, I shot it with my iphone in the parking lot of the hospital where I work
Modified by Kujo II at 7:01 PM 12/31/2009

[AZhitman]

Here's a list of what it's not:

It's not a rod, I pulled the pan, bearings look good,

Nope.

"Bearings look good"? Unless you disassembled the engine, you can't SEE the bearings.

Revving it in neutral was the clue, and I'll bet it quiets down under load.

I'd bet $$$$ you have a spun rod bearing. I had the same identical sound on the same engine. Mine was cracked in half, but it was still in place (weird).

Motor swap time. 248K means she gave you all she had.

Wish I could buy a double cheeseburger with your undying gratitude.

[Kujo II]

Nope.

"Bearings look good"? Unless you disassembled the engine, you can't SEE the bearings.

Lol I did disassemble the engine. I pulled the oil pan, main cap girdle, and rod caps, They all looked ok so I put it back together. I figured I'd drive it to work, which was 80 miles, and if it was a rod I'd be hitchhiking.

[AZhitman]

That only shows you 1/2 of the bearing. I'm still betting that's the issue.

Does it make the noise less under load?

[Kujo II]

Actually, it makes noise on acceleration, no noise on decel, which is opposite from most rods I've heard... That's why I'm so confused, it sounds like top end, and I checked the locks on the rod bearings, they hadn't been sheared, (and I knocked the piston up and looked at both halves) but it acts like a rod bearing, and everything checked out in the valve-train.

You're prolly right though, at 248k, I should probably just call it a good run and swap my other one in

[AZhitman]

Yep. If you were able to knock all 4 pistons up, pull them back down, retighten the caps, and slap it back together, it's loosey-goosey to begin with.

Hell, get a AAA membership and drive it 'til it croaks. No sense wasting $ if you don't have to - it might knock and rattle for another 30K miles.

[Kujo II]

I just thought about something, it has had a blown head gasket, could it possibly be a galded piston? I've never seen one in person, but I know that sometimes happens when an engine gets hot...

[AZhitman]

Does it get more noisy when cold than hot?

Kill one cylinder at a time while it is idling and rev it. The freewheeling piston won't be as loud if it's galled.

[Kujo II]

I'm not sure, but that will be the first thing I check tomorrow after I get off work (provided I make it home:) Thanks for all the great input, sometimes it helps to have a fresh set of eyes. Looks like daily redlines are the order of business for a while

[liquid_cool]

im curious: are you shure your not slapping the valves with your pistons?..when you changed your headgasket..did you inspect the pistons?.

[liquid_cool]

it really sounds like a timing chain guide...or slapping valves..like your a tooth off on the timing..dosent sound like a rod to me..allthou it could be.

[greencar]

when you replaced the timing chains/ tensioners, what brand did you use? OEM? my car made the same noise, it was a tensioner for me, but it made that same sound.

-Dan

[zerepdivad]

Sound exactly like my sohc that knocked, and another ka in a 240 i was looking at that was knocking. rod knock is definitely what it sound like. I have had chain noise in a few ka's but didn't sound like that.

[ss82480]

Don't suppose you have pulled off your water pump belt and ran it? It doesn't sound quite like it, but they make a higher pitch knock like that. Mine went out and sounded like that.

[sh3lby240sxsm]

its deff rod knock and it sounds like coming from top end becouse when A rod bearing get worn it makes the pistion to hit the head in the cylinder. and when u took it apart it will look fine becouse the clearances r so small u could never tell un less ur using micrometers or plasticgauges ON the rod jornels, and + thares 248k on it and 20 years, time for a rebuild! im in the same boat, + u said u have the extra motor rebuild that one wile u drive the motor knocking on heavens door. thats wat im doing good luck