I had my topspeed headers and an Injen Exhaust recently installed. Today was the first day i really drove the car. Im experienceing upon deceleration a weird bubbly/flapper liek sound when i begin to decelerate. Also a second symptom is my RPMS at idle move and shake between 200-500 RPM. It is my guess that i may have a leak somewhere on the headers or the exhaust. Would this make sense to you guys? By the way the car itself is running awesome and already feel the gains. The first day it had none of this until i really drove it today on the FWY and for a few blocks.

FYI-I was advised that a few days later I would eventually have to bring the car back to readjust the Injen exhaust after it heats up since this ones tend to move with heat or something or expand.

 

Headers usually need to be re-torqued after a while, too. I would think that you would hear an exhaust leak more under throttle than decel. It would sound like a loud ticking noise. The bubbly sound might be the headers and exhaust just popping the air out. I have very similar sounds under decelleration. I noticed it after putting on my test pipes, in conjunction with my Borla True Dual exhaust.

 

Hmmm..........so I guess it should be normal for those bubbly sounds on decelaration then. I do also have crawford's high flow cats.

 

Why do the RPM's jump at idle though?

 

I have had a rough idle since new. It seems to have gotten more pronounced with the addition of my mods. If it isn't too bad, I wouldn't worry about it. I know that there are a lot of Z's with a rough idle.

 

Ok thanks for the input. its just that I didnt get this needle jumping thing until today the second day after the headers went on and the exhaust. I guess i shouldnt worry too much then.

 

yeah the borla is known for that bubbling bc most ppl dont weld it. it comes in pieces so even if the gaskets are tighter than a virgin on prom night air still tend to "pop out" jmc man i dont know what to tell ya bout your idle. it could be so many things i know turbo guys who have trouble bc the ecu overheats etc. its not really an easy thing to pinpoint

 

did you use the paper exhaust gaskets that came with those headers?

if so... they are most likely blown out...

use your stock ones...

 

really? they can blow just liek that? Well the gaskets that came with them were metal. At least they looked liek metal? You think its somehtign that can be easily repaired? What about the idel could it be because of..........?????

 

yes, just need to replace your exhaust gaskets... we can do that for you, but its as much as installing the headers...

the place that installed them should have known this...

They looked silver with little dimples in it?

if so... those are gaskets that have a thin metal out side and a fiber / ceramic type material on the inside.. not sure exactly what it is...

its the same gasket material that comes with pretty much all cat back exhaust systems...

anything but true metal gaskets dont work well on the manifold / and between the manifold / cat's

 

Yes it is a metallic looking gasket with little dimples........that came with headers. Hmmm.........I wonder if that place where they installed would replace them for free of charge on labor.........if i continue to drive like this would it hurt the engine?

I was going to do it at ur dealer but you guys said u couldnt since they were not carb legal. So this is the reason for the weird jumping RPM needle at idle?

 

This type of gasket comes with the NISMO Cat Back as well as many others... They generally cannot be re-used and blow out...Most everyone with these on their exhaust has them blown out...



Here is the actual factory exhaust manifold gasket for the 350z... these can be re-used and are extreemly hard to destroy...

 

it could be since you have an exhaust leak back pressure gets screwed up..

we cant install headers...

we can replace your exhaust gaskets...

 

Hmmm........Yep those dimpled ones were the ones hat came wit hmy headers. DARN. Shoot, does it mean i should stop driving it? and is it the reason for the weird idle?

 

The Injen exhaust is to be blamed for your odd idle. I have the Injen exhaust also and used to get the same type of sound you're describing. Kinda like a helicopter sound. I added a H pipe to my exhaust and got rid of the sound completely and IMO sounds deeper and throatier than before. It also adds some back pressure to the system and regains some lost torque.

-Bootay

 

Darn another $400 for just gasket replacement? Darn. If i can drive liek that I will for a while since I already have to pay for my kit painting. Once again Jason thanks for all ur help!

 

If you dont mind me asking how much was the H pipe mod? Im really wantign to add this!

 

It depends on where you go. It's not a tough mod, so it's going to run you anywhere between $50-$100. Do a search on H or X pipes if you're needing more info first before you commit. Good luck....that's going to suck if you need to replace your exhaust manifold gaskets.

-Bootay

 

sorry to be the barrer of bad news... But people need to be informed...

One of our customers came in, his clutch was always getting stuck on the floor after hard acceleration...

the problem?

the paper gaskets that were used between the header / cat blew out, the exhaust heat would shoot out of the drivers side against the clutch line (not the one that can be replaced with a steel braided but the fixed hard line)... and melted off the heat shielding and caused the clutch fluid to boil under hard acceleration...

you can still drive the car.. just not too hard....

 

Oh ok..........Thanks again everyone!