07 2.4 lt, 3" zzp stainless piping, 3" zzp downpipe. new o2s, new headers.

Drove fine for about 1/2 weeks.. Now all of a sudden, sounds like a tractor under the hood.. Especially in gear, past 1st gear.. I tried to duplicate the sound in driveway, in park and in neutral. We can reproduce the sound.. Only when driving it.

Process of checking all the bolts on teh exhaust system right now.. But was wondering if anyone else has experience this and can point in a general direction.

Addition: I did use all the gaskets that came with each kit. Including the manifold gasket, was a single gasket, vs stock 2 gasket set i pulled off.

 

Check for leaks... Old fashioned way have somebody plug the tailpipe with a rag. listen for leaks.

Also make sure it's not hitting anywhere... could be it has shifted a little.

 

I'm under it now. Few manifold bolts were loose, and down pipe bolts. All retorqued and made tight again. Drove it around block and noise is still freaking there.

Ill have to grab a towel, but 3" tip on it won't take just a shop rag, lol.

 

Just tried the towel trick, still didn't replicate the sound, even blew the towel out about 5 feet from tail pipe lol.

All bolts are tight, everything shifted back into place. Still only making the sound when the car is physically driving, if in drive and sitting, no noise, get above 5 mph, you'll hear it and faster you go, louder it gets.

 

Hubs. That's what my first sounded like; people on the interstate were turning their heads at the noise.

 

I've dealt with hubs before, deffinently don't sound like a hub. Sound is coming from what sounds like back of motor towards the bottom (checked oil as well, its good).

Just installed brand new hubs, I do understand you can get bad new ones right from box, but that normally sounds like a growl or jet engine.engine this sounds like a tractor motor.

 

3 inch pipe... Could be drone.

 

Oh i have drone, its at the tail pipe.

Ill see if I can grab audio clip tonight when I take the car.

Hubs; I did the shake test, was no wiggle at all, another way to do the test?

 

Problem s at the header and downpipe? Tight bolts but blown out gasket at the header flange or the two bolt flange before the resonantor ?

 

I can't tell if its the header/engine area or the header/down pipe area. My header to downpipe is 3 bolt..

I even checked the 3 bolts at downpipe to resonator.