The Plastic Lizard

So I have a c4 with an ls6 I recently swapped. I haven't driven it out of my neighborhood until today. That's because I didn't have an exhaust and was just running open.

Today I went to get the pipes installed and after about 6 miles of very loud, but gentle running....it got very rough.
I was hoping that it was just not enough back pressure was messing up the o2s. But it turns out I had a crack behind the throttle body






1. Which is chicken, which is egg? The crack or the rough running?
2. Was this most likely cracked when I got it 6 months ago, and I just didn't notice until it heated up?
3. Anything else to check?
4. Can I just solvent weld this, or is the intake toast?

Zmg00camaross

iTrader: (11)

intake cracked and caused vacuum leak and rough running. No idea if it was pre or post install. I would say you definetly could seal it up. Jb weld or some kind of epoxy.

N20zuki

I would stop drill the cracks and then epoxy it, As long as you don't mind it being ugly looking.

Did you get the motor from a wrecked car?

The Plastic Lizard

Yes. Rearended c5

redbird555

iTrader: (14)

I would drill it then look for epoxy that BONDS to Nylon 66 which is what he intake is made from. Theres a link somewhere on here in a diy thread for fixing one its 25 bucks a tube but the fact is ts the only thing made to bond to that type of plastic. You could plastic weld it but you would need a peice of scrap from another ls intake

garys 68

iTrader: (1)

There are a couple threads on plastic welding nylon 66, including a video here. Probably best bet, followed by epoxy. I always drill the end of cracks to prevent them from starting again.

jlcustomz

You can get nylon 66 black tie straps from harbor freight & many places. Not 30 percent glass filled like the intake, but still suitable for welding .
Donor engine likely got hit in front OR manifold separately took a hit it wasn't designed to take. cracked didn't likely happen on it's own. Rear vacuum connection is another fragile area.

SS Rider'z

I recently repaired mine by plastic welding it with a butane soldering iron pen.. gets real hot melt the crack fill with nylon zip ties & cover with epoxy.. Mine was much worse, on the rear map sensor spot whole thing broke off.. Its good now..

JS30612008

Plastic welding will do the trick. Just prep it correctly might be ugly but it works

LilJayV10

iTrader: (39)

This is what I used to fix my broken LS1 intake. Stuff is freakin amazing.

http://www.rapid-fix.com/