rattle near front of tranny or back of engine

[parish8]

sounds like a lose heat shield or maybe the loose guts in a cataletic converter.

i used a stethascope and cant seem to isolate it. sounds like it is coming from the back of the engine or front of the tranny. maybe the converter. there are no loose heat shields, not coming from the turbos. i cant think of anything in the back of the motor that might sound like that. could there be something in the tq converter that might sound like that. seems like it would be full of oil and be muffled if there was something loose in there.

oh yeah, only does it in park or neutral. quiet in drive or reverse. fairly loud. i looked at the bolts from the flex plate to engine and the tq converter bolts. just looked, they are all in and look tight. i suppose i should get in there and make sure the tq converter bolts are tight but i used locktight on them and got them pretty tight.

any ideas?

[GeoffA]

The only suggestion I have because you said heat shield sounding is to check your exhaust. It might have loosened up and is sitting on the rear crossmember. I thought I had the same problem with a heat shield and when my car would warm up the sound would go away. It turns out my pipes were sitting on the rear cross member.

[GeorgeInNePa]

Cracked flex plate?

[parish8]

the sound definatly seems to be coming from the tq converter area. cracked flex plate seems like an idea. i looked but you cant see much thru that little hole down there.

i think i will call circle D today and see if there is anything in that convter that could make that sound. it doesn't seem muffled enough to be inside the converter or tranny.

[99-LS1-SS]

This might be a stupid comment but, I have been reading about clutches a lot lately and it seems that the twin disc clutches are great for drive-ability and holding power but the middle section between the discs rattles at idle. I wonder, since you have a multi-disc converter, if it isn't something similar. If it is odds are it's just a noise that doesn't really hurt anything. I would call Circle D either way just to make sure.

[Devilish34]

Cracked flex plate?

I was thinking the same

[parish8]

This might be a stupid comment but, I have been reading about clutches a lot lately and it seems that the twin disc clutches are great for drive-ability and holding power but the middle section between the discs rattles at idle. I wonder, since you have a multi-disc converter, if it isn't something similar. If it is odds are it's just a noise that doesn't really hurt anything. I would call Circle D either way just to make sure.

it is fairly loud and didn't do it right after the converter install. took at least 500miles to start.

the more i think about it the more loose converter bolts seem likely. if they are loose enough to make that sound i should be able to spin the converter a little each way. if it is that i am not sure how to properly tighten those bolts. i got it tight with a wrench, then used a hammer on the wrench to get it a little tighter and i used the supplied lock tight.

i am going to get under there today and look again and try giving chris a call too. seems loud enough that i shouldn't be beating on it till i have a better idea what it is.

[99-LS1-SS]

Good luck Parish. Post your findings.

[13 QTR]

yea...I get that sometimes....it did it with the 2200 stall and the circle d 3k.... It's been out a couple times...nothing I can see. Maybe the pressure low in the convertor. Mine is mostly when it's not up to temp yet.

[bigwillys58]

parish, it sounds like your converter is comming lose from the flex plate. mine did the exact same thing... twice. no noise in drive and reverse is because the converter is loaded where in neutral and park it allows it to bounce around. mine took about a thousand to start the first time and only a couple hundred to start the second time. ended up having to git different bolts with a shorter shoulder on them. havent had a problem since. hope this is your problem.

jesse

[Crazy Paul]

From left field:
It's not that silly vent pipe for the auto trans, plastic pegged to the back of the left cylinder head rattling is it?

http://i2.photobucket.com/albums/y20/PerthPurplePenguin/car%20parts/Instructions/Trans-vent_03.jpg

[parish8]

it is not the converter bolts. i was hoping it was. i got some video/audio of it. pretty loud. i will post it up later.

i went ahead and over filled my tranny by 1qt to see if it fixes my loss of line pressure off the line. you never know. may not get back to the track for a week or two to test that issue.

[vic2186]

Throw a set of rods and pistons in there..lol ..hey do ls2 rods and piston fit our motors

[parish8]

http://www.neufamily.org/images/g8filespics/noise.wmv

check it out, anyone got any ideas?

[13 QTR]

no clue.....my slight random rattle noise doesn't sound like that. Mine kinda sounds like what it does when you shake a empty tq convertor in your hand.

[desertg8]

mine did this after an oil change. they told me they did not align the inspection cover correctly. who knows?

[parish8]

do you know what inspection cover they were talking about? car is still making the sound. no better, no worse.

[Crazy Paul]

Throw a set of rods and pistons in there..lol ..hey do ls2 rods and piston fit our motors
Rods yes, pistons maybe not. Some are saying the car L76 bore is smaller than the LS2 4" bore.