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Author Topic:   engine rattling
DIRTDOG311
Dirt Full Roller

Total posts: 36
posted March 31, 2005 06:29 PM  
I have a 350 chevy with a turbo 350 tranny with only 2 races on it. The problem is whenever I start it up, it sounds like every rod in it is on its way out. If I rev it a little it quits and it also quits after it warms up. If you listen from underneath the car, it sounds like it is coming from the torque converter, but it is tight and the flywheel is tight. If you listen from the top side of the car, it sounds like a rod knocking, but I have turned it 6500 at the track for two races and it still runs good. Someone told me it could be the lifters not pumping up fast enough but I wouldn't think that sound would be coming out by the torque converter. Any ideas?

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Pickel
Dirt Forum Champ
Total posts: 784
posted March 31, 2005 06:51 PM  
Doesn't sound like a wrist pin.

pit_boss
Dirt Forum Racer

Total posts: 80
posted March 31, 2005 07:52 PM  
I agree with Pickel on this one, A wrist pin will rattle when cold and disappear after it warms up, If it were a rod it would have knocked itself out by now.

supwitchew
Dirt Maniac

Total posts: 122
posted March 31, 2005 09:00 PM  
I agree too. Mine did the same thing. 36 races later it still does it until it warms up. My pins were bushed. I was just told to make sure it's warmed up before turning any rpm's with it.

dirtracer14
Dirt Forum Champ
Total posts: 1261
posted March 31, 2005 09:45 PM  
The other thing it might be is if the block was honed and the ridge was left ....the new rings will hit and make a noise.....done it a few times....was lucky not to break a ring!!

iowatoolman
Dirt Freak

Total posts: 369
posted March 31, 2005 11:28 PM  
or it could be piston skirt slap

where the skirt of the piston doesn't have enough to keep it square in the bore when cold (because the piston hasn't expanded to fill the bore size)

just a thought

drive hard or drive home
and run it till it blows then build it again just to have FUN

rfb320
Dirt Maniac

Total posts: 150
posted April 01, 2005 05:48 AM  
Double check all the bolts in the torque converter. One bolt came loose on a friends car last year and it sounded like the engine was knocking.

dirtracer14
Dirt Forum Champ
Total posts: 1261
posted April 01, 2005 05:51 AM  
There could also be a crack in the flex plate....makes it sound like a rod coming out!

droper23
Dirt Freak

Total posts: 233
posted April 01, 2005 06:20 AM  
I had a motor do that. You could only here it at idle, and we dug and dug and found that we had a rod barely tapping the edge of the oilpan.

mansfief
Dirt Maniac

Total posts: 128
posted April 01, 2005 07:05 AM  
As already stated, it is your flyweel. The bolts are loose or flyweel cracked.

autoshop
Dirt Freak

Total posts: 298
posted April 01, 2005 08:11 AM  
just unbolt the trans from the engine via the convertor bolts and start it up if the noise is still there it's in the engine if it is not it's in the trans,.

[This message has been edited by autoshop (edited April 01, 2005).]

racer2
Dirt Freak

Total posts: 352
posted April 04, 2005 07:32 AM  
cracked flywheel

pit_boss
Dirt Forum Racer

Total posts: 80
posted April 04, 2005 07:52 AM  
DirtDog stated you hear the noise when its cold, and the noise dssappears after it warms up, if there was a converter or flywheel problem it would be a constant noise, warm or cold.

DIRTDOG311
Dirt Full Roller

Total posts: 36
posted April 04, 2005 06:47 PM  
Thanks for all of your ideas. I don't know what it was, but this saturday I turned it 6900 rpm and it spun a bearing. Time to rebuild now.

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