Y-Block Death Rattle?...Help

My car has sat untouched for 2 years, I decide to get it running again. 1957 Y-Block: Changed the oil, pre-lubed the engine, and fired it up. Was making a little noise so I adjusted the valve lash (thanks HAMB member Ole Don for the tips). The valve train is now quieted down, but now I hear what could be a death rattle from under the car...but I don't know. It makes the noise at idle and a little above idle, but does not seem to increase with RPM, and seems to go away after 1500 RPM. I posted a video of it below (I hope). Anybody care to help me out with this....spun bearing, piston slap???...I hope it's some strange Y-Block rattle that is actually beneficial, ha. Thanks in advance for the help.



http://www.youtube.com/watch?v=02mA6Z0I57I

 

Unfortunately im trying to watch it on my phone and its hard to tell what it is.

 

do you have good oil psi, maybe water pump, balancer or fan, or flexplate, just a guess,

 

Wow that is not a good sound! Sounds like something is dry. Yikes. Whats your oil psi???

 

Hard to say where it's coming from on a vid. If it sounds inside the pan, I'd stop right now and drop the pan.

Post #3 ideas are good to check out.

 

Oil pressure is 50psi at idle and increases as RPM's increase. I just took off the fan belt and started it, but the noise is still there.

F&J: It does sound like its from the pan, but I can't tell for sure. If it is something internal like a rod (ouch), wouldn't the noise increase with RPM, or is this not always the case. Thanks for the help.

 

Every bad rod I have heard has an RPM that it does not want to be at so, it should change.

Hey, here is a thought that just hit; I was wondering why it was OK 2 years ago, and now it knocks..... is there any chance something fell into the carb or maybe a chunk of carbon sitting on the piston?

What's your thought?

 

sounds like my buddys truck. he thinks its the cam bearing let loose and the cam is wabbling around in it, because its an uneven tick like a crank or rod bearing would be.

 

Wow!!!!! Rev her up to about 5k then you will know for sure what it is lol. Tear it down...

 

holly crap...mine makes the same sound all of a sudden.... be sure you post what you find!! just saw your avatar... same car too!

 

Yikes sounds bad. Sounds like something got loose and is rattling around in the bottom of the oil pan from vibration.

 

F&J: I don't know why it was okay 2 years ago, anything that sitting for that long screws up? I cleaned the carb (actually cleaned that gas tank, and re-did the fuel lines too) before I started it, but I covered up the manifold while the carb was off, but ya never know. It does kind of sound like something bouncing on top of the piston....I guess I will pull the pan first though and see what I see.

 

Have you checked the tranny fluid? I once heard an engine sound like that, it was out of tranny fluid and the front pump/converter rattled like hell. Put fluid in it and it quieted down...LOL

 

Timing Chain? Pump Pickup? Best to yank the timing cover and oil pan and see what's going on, no sense in guessing.

 

Check the torque convertor to flexplate bolts. My kids Chevy truck did that. Sounded like it was going to let go through the pan at any second. Tightened them up,noise gone.

 

Jeez 42hotrod you almost got me excited when I read your post! I ran out and checked the tranny fluid after reading your post....unfortunately the fluid was not low. Good tip for the future though, thanks.

 

Pull the Starter and check the Bendix isnt hanging plus take a look the ring gear hasnt came loose,

 

It sounds like a cracked flex plate to me, put it in gear and hold the brake, see if the noise changes.

 

If it has a automatic trans it could be the front pump,the FOM that originally came in my 55 was a little noisey

 

Thanks for all the suggestions. I am going to let it cool down then first check the flexplate and torque converter, the starter, and then pull the pan.

junkyard: it is an automatic. Excuse my ignorance, but how would I check if the pump was making the noise?

ecode: tried your suggestion, there was no change in noise, I will still check the flexplate though. Thanks

 

A rod won't screw up just sitting, but a big chunk of carbon can fall off, or something got dropped in there.

I was looking for a problem with a 56 olds motor, and I could get a view down most of the plug holes, using a mirror with the sun. You could move each piston down to the bottom, to see better.

 

I had a loose starter in a '56 once that would start the engine ok
but then sat there and bounced around on the loose bolts and kind
of sounded like that.

 

make sure the oil is draining back to the pan properly. I had a sludged up y block years ago that hd a drain back problem and it starved the bottom end for oil.

 

Hard to tell from your video but I don't think it's a rod knock. I'll go with the flex plate or maybe the damper ring has slipped off the front pully.

 

Check compression rule out broken con rod. Sounds like something hitting or rattling around in the pan.

 

I think you might be able to disconnect the torque converter from the flex plate and still be able fire it up to see if the noise is in the trans.

 

Mice

 

Is the fan hitting anything? Bad water pump? Coolant in radiator? Sounds like something hitting a sheet metal cover. Also check cover on torque converter.

 

Did this start after adjusting the valves? If so something has fallen into the pan.

 

Mechanics stethiscope will at least rule out your engine accesories and localize your noise....I hate what I thought was a death rattle when I reassembled my sbc...turns out the oil dipstick was at a funky angle and getting whacked by the crank.....sounded all sorts of evil till I pulled the dipstick out.