Header Noise - Opinions needed!!

[orange04]

I have a 08 GT500 with JBA Long Tube Headers and Off road X-pipe and pulley and intake. Im getting this rattling noise coming from under the drivers side of the car under moderate acceleration only. Noise can not be heard free revving. Also the noise is worse when its cold. Noise starts at 2500 rpm and quits after 3000 rpm. Been up and down the exhaust, no contact anywhere and cannot see or hear any visible leaks. I originally thought the tubes were rattling against one another so I put spacers in the tubes, no change. I'm about ready to take the long tubes off and install the manifolds and an offroad x pipe.

So a couple questions.....

1. Have you guys ever run into this??

2. If I remove the headers and put an offroad X the car how much power do you think I'll be loosing in the long run??? Future plans are to run either a 2.9 Whipple or a VMP TVS.

3. Do you think it could just be the way JBA Headers are? I know alot of guys are running Dynatech and ARH, should I switch brands?

Thanks for any help in advance, its driving me nuts!!

 

[ivandrea]

I have a 2008 vert with JBA headers and catted x-pipe, full 3" pipes to the tips. No rattles. There were some spots that i thought would rattle in the rear because clearence was close, but no issues yet. Are your heat shields bent or not secured to the body?

 

[orange04]

Thanks for the reply.

I went over all the heat shields and even reshaped some thinking they would resonate when pinged.

The thing that is strange is that its only under load so something if moving and hitting when the motor is torqued over.

Now its got me thinking maybe its not header related and something else is vibrating....

 

[orange04]

I have a 2008 vert with JBA headers and catted x-pipe, full 3" pipes to the tips. No rattles. There were some spots that i thought would rattle in the rear because clearence was close, but no issues yet. Are your heat shields bent or not secured to the body?

Are you using the supplied header gaskets from JBA or did you reuse the factory gasket?

 

[Robertt305]

Check the header bolts to make sure they are tight.

 

[orange04]

Check the header bolts to make sure they are tight.

Ive tried that too!! What's weird about that... if it was a header leak wouldnt I hear it all the time? It should not just happen under load?? Am I thinking about this correctly?

A couple Ford techs said 2500-3000 is a rpm that vibrations are most prone at. That what is leading me to something rattling.

 

[Robertt305]

I had a leak that I ly heard under load. It was 2 bolts that backed out

 

[orange04]

I had a leak that I ly heard under load. It was 2 bolts that backed out

Thats crazy, ok maybe I should take a look to look and see if there is a leak at the head. I have those felt gasket supplied by JBA in there now.... if I take it apart do you think the factory gaskets will work or should I get new gaskets from JBA?

 

[Robertt305]

I used factory

 

[orange04]

Thanks Robert!! I'll take a look into that this weekend and report back. I was wondering if they would work because of that raise portion on the flange right at the port.


Please keep any other ideas coming!!

 

[Blackmax]

If your headers are the same as my Dynotechs this might apply. I had the same type of noise and after a couple of frustrating days found a 3/8" open end wrench had fallen between the tubes and was sitting in front of the collector. Not my brand of wrench either! I also had to tighten collector bolts a couple of times.

 

[2011SVT]

Smoke test them. Header leaks can manifest in so many odd ways.

Assuming nothing is found there look for contact - specifically the steering shaft.

 

[orange04]

If your headers are the same as my Dynotechs this might apply. I had the same type of noise and after a couple of frustrating days found a 3/8" open end wrench had fallen between the tubes and was sitting in front of the collector. Not my brand of wrench either! I also had to tighten collector bolts a couple of times.

LOL!!! I'm glad you found that!! I actually checked that too!! One time I had a header bolt stuck on the collector on a car that rattled like crazy!!

The headers I have are JBA's.

 

[orange04]

Smoke test them. Header leaks can manifest in so many odd ways.

Assuming nothing is found there look for contact - specifically the steering shaft.

Steering shaft looks good. Whats the best way to smoke test an exhaust system??? I have access to a smoke machine from a Ford dealer. Should I just plug the tailpipes and inject smoke through a oxygen sensor hole??? Is there a better way?

 

[Darren5.0L]

A friend of mine has this same noise on his S/C Marauder with Kooks, longtubes, an EGR Delete solved the issue.

The EGR on the headers only feeds from one primary and would rattle at part throttle load only.

 

[orange04]

A friend of mine has this same noise on his S/C Marauder with Kooks, longtubes, an EGR Delete solved the issue.

The EGR on the headers only feeds from one primary and would rattle at part throttle load only.

That makes complete sense!!! Something else I will try. The egr feeds from the passenger side header. Wonder if the noise could transmit though. It is definately worth taking a look at. Thanks.

 

[Darren5.0L]

The theory is that the EGR valve was fluttering as it got hit with an exhaust pulse and then dropped until the next one popped it back open. On a log style manifold you have 4 pulses that feed the EGR. His was loud enough that we were worried the valvetrain was having issues, but it would never do it at idle, free revving, or WOT, even with a stethoscope.

It only occurred under load, 5 to 0 inches of vacuum from about 2,500 to 3,500 rpm, being an automatic car it was very common to have it dwell in that rpm range during highway merging, or climbing a gentle hill. It would simply rattle like hell.

We tried a lot of leak checking etc, and finally deleted the EGR and the problem vanished. I can't say 100% that it would be your issue, but it's something that is cheap to test out, and if it works you'll get to keep from pulling your hair out any longer.

When we took the EGR off and shook it we got a very similar sound to the "tack-tack-tack" noise we'd heard...

 

[orange04]

The theory is that the EGR valve was fluttering as it got hit with an exhaust pulse and then dropped until the next one popped it back open. On a log style manifold you have 4 pulses that feed the EGR. His was loud enough that we were worried the valvetrain was having issues, but it would never do it at idle, free revving, or WOT, even with a stethoscope.

It only occurred under load, 5 to 0 inches of vacuum from about 2,500 to 3,500 rpm, being an automatic car it was very common to have it dwell in that rpm range during highway merging, or climbing a gentle hill. It would simply rattle like hell.

We tried a lot of leak checking etc, and finally deleted the EGR and the problem vanished. I can't say 100% that it would be your issue, but it's something that is cheap to test out, and if it works you'll get to keep from pulling your hair out any longer.

When we took the EGR off and shook it we got a very similar sound to the "tack-tack-tack" noise we'd heard...

Thanks for the detailed explanation. I was able to find a plug for the egr bung on the header and a plug for the egr tube so this should be easy to test. Driving the car this morning your explanation is making more and more sense. The noise sounds like it is left front so I'm wondering if the carbon fiber intake and 123 MAF is actually amplifying the noise from the egr valve.
Will test this this weekend and get back to you! If this works you're a life saver or hair saver. :beer:

 

[mikesfagent]

I have the same noise, and know of at least one other guy w/the issue too-

I would swear it is right behind the pedals, so I have my eye on the heat shield resonating as the cause of this. I have stage 8 locking header bolts, so I doubt it is those. Rattle is in exact same range, part throttle, under load only.

My plan is to put some dynamat/sceond skin product on top of the heat shield-I figure this should kill the resonace if that is it. the second skin damplifier mat is rated to 500 degrees, so on top of the shield it should be ok. I have the stainless works headers, so I highly doubt that the issue is the header brand itself as it seems to exist across several brands.

It definitely will drive you nuts...makes you feel like you are driving a $10 car, not a 50k car

I had not thought of the egr as the issue, as it seems to be right under my feet, not off to the passenger side where the egr is...


Let me know what you fin out

mike

 

[orange04]

I have the same noise, and know of at least one other guy w/the issue too-

I would swear it is right behind the pedals, so I have my eye on the heat shield resonating as the cause of this. I have stage 8 locking header bolts, so I doubt it is those. Rattle is in exact same range, part throttle, under load only.

My plan is to put some dynamat/sceond skin product on top of the heat shield-I figure this should kill the resonace if that is it. the second skin damplifier mat is rated to 500 degrees, so on top of the shield it should be ok. I have the stainless works headers, so I highly doubt that the issue is the header brand itself as it seems to exist across several brands.

It definitely will drive you nuts...makes you feel like you are driving a $10 car, not a 50k car

I had not thought of the egr as the issue, as it seems to be right under my feet, not off to the passenger side where the egr is...


Let me know what you fin out

mike

Deleted the EGR last night and the exhaust noise is overall quieter but the noise Im after is still there. With the egr deleted a light rasp when free reving is gone and when the engine is first started it sounds much cleaner. I actually thing the exhaust sounds better with the valve deleted. The noise Im after can be heard more clearly now. Going to put the car up in the air and check some other things out and will report back.

I know what you mean about the car feeling cheap. Im at a point where iys not enjoyable to drive anymore.

Thanks for the reply!