Ran fine when I parked it Saturday, now knocking.

[Rafs-T-Type]

Just making sure you didn't have any boys around 16

 

[slamming 6]

If all else fails check for a cracked header.You would'nt think it could sound like that but it did on one of mine.

 

[robzombie]

Check torque converter bolts!

Pull the torque converter shroud, and make sure the bolts have not come loose. There should be no rotational play.

If loose it will have a lot of apparent knock at idle, but will smooth out at a higher idle.

X2. Been there done that. That would be my bet also.

Same thing happened to me, and sure enough after new trans install and a few hard pulls a few days later I heard that knock at heavens door, but I knew what it was and tightened them up and haven't heard from them since.

 

[gn4u2c]

prolly just the downpipe hitting the frame.. yeah right.. looking at your mods and a stock lower.. somethings broke.. been there done that. 500hp combo on top of a stock lower is just a matter or when. I have had them last years others .. well not so much.

 

[threerail]

I had my water pump pulley back off on me and it sounded like I blew a rod or two, check those real quick too

 

[czimpel]

Excellent, thanks guys!

I just put the new trans in this winter, I'm hoping like hell it's the torque converter bolts. When I was crawling around under the car I was trying to decifer whether it was the trans or engine and it was difficult to do, but the trans was still functioning so I leaned towards it being motor related.

I know my combo looks like a higher horse combo, but I'm only running 15 psi right now, and it has never seen more than that with me.

Someone above mention that the knock went away when it was warm, but I never ran it longer than about 1 minute so it never got warm. Just when I gave it a LITLE throttle the idle straightened out it and the knock quieted a lot.

 

[robzombie]

Just when I gave it a LITTLE throttle the idle straightened out it and the knock quieted a lot.

That's what happens when you put a load on the loose torque bolts as there is rotational pressure put on them under a load and it reduces the wobble in and out and back and forth with the added force on them .

Just check them before you start it again, you could do more damage if left unattended, like oblong the flex plate holes or worse ruin front seal or front pump.

I hope this turns out to be your problem as it will cost nothing to tighten the bolts.

You may want to use lock tite or lock washers if this happens again if it turns out to be the problem.


RZ

 

[Franks86gn]

Loose converter bolts has happened to me before on a small Chevy. I thought the bottom end was going to blow out.

 

[czimpel]

Damn you guys are awesome. I had a couple minutes today and pulled the TC cover. TC is loose as hell. Glad it will be an easy fix, hope everything is ok with that.

Thanks again, I was ready to pull the pan.