Kevin509

Hey all,

I installed a pypes off road X pipe last week and at first I definitely had an exhaust leak that was audible at idle and throughout the RPM range and I could actually smell exhaust if the car sat still for an extended period like at a stop light with the windows down.

Since then I've taken the X-pipe apart twice and resembled it, first adding copper RTV at all the connections and then adding the included inserts at the manifold to down pipe connection.

I don't think I have an exhaust leak anymore, the exhaust smell is gone when sitting for an extended period and the sound is no longer there at idle, nor is it audible when revving the engine under no load. But under load I'm still getting a ticking sound like an exhaust leak. Now I'm wondering if that's just a natural noise that occurs with an off road x pipe, like a sort of "header tick" some people get after installing LT headers?

05YellowGT

If you're getting a ticking sound only under load , it could mean you're running lean.

Kevin509

It's definitely not detonation if that's what you mean. The sound is coming from the exhaust and sounds like an exhaust leak. I'll try to take a video.

06BlueGT

Have same problem with pypes o/r x pipe. Mine is audible for about 30 seconds from cold start, and then it goes away. Only other time it can be heard is when it is under a significant load. Yesterday I took it all off, used permatex copper rtv on the flanges on the x pipe and bolted it all back up. Let it cure for 24 hrs. Started it up and it seemed to maybe be a little quieter. Checked everywhere, I have 0 leaks. When I cold start it and get under the car really fast its a loud tick that I can hear the whole length of the passenger downpipe, not at just one connection like a leak would be. drivers side makes no noise. It has to be some sort of tick coming from the heads or engine.

Kevin509

Glad to hear I'm not alone!

So, do you think that this is just natural valvetrain noise being amplified by the new pipes or do you think there's something wrong that's making an excessive tick? My car is pretty unabused with 46xxx on the clock...

05YellowGT

I started hearing a ticking sound , which I at first attributed to the injectors like most people do , it would come and go. However it keep getting louder and more frequent and it turned out to be a rocker had collapsed on the roller and the cam hitting the stuck roller was making the ticking sound. I also had some small metal flecks in my oil due to the cam wearing. Just an FYI ...

Kevin509

Would that be something I should be able to pinpoint with the 'screwdriver-stethoscope' technique on the valve covers if it were the problem?

05YellowGT

Actually it didn't sound like it was coming from the valve covers and before they pulled the covers they thought that it was just a sticking lash adjuster. Like I said I had small metal flakes stuck to my magnetic drain plug due to the cam wear. If you don't have metal in your oil it could be just a lash adjuster that need replacing.

Kevin509

I'm pretty green, mechanically speaking, but willing and able to learn, do you know what I would look for once I pulled the valve covers to confirm that there is a problem? As in, would there be something that was obviously "broken" looking or is it more subtle than that?

Some additional information that may or may not be relevant, the sound is most noticeable between 2 and 3 thousand RPM, and goes away completely beyond 3500 or so RPM. At first I thought maybe it was just drowned out by the sound of the exhaust a higher RPM, but now I'm pretty positive that the sound does go away above 3000 RPM...

05YellowGT

On the rocker you could see where the vertical side wall had compressed down on the roller and there was a flat spot on the roller since it wasn't turning , so that was pretty obvious. If it's just a sticking lash adjuster I'm not sure how you would tell which one it is. Also on mine the sound was most audible at idle when the rest of the engine noises were less.

06BlueGT

Mine is audible at any point in the rpm range if I give it enough gas. Anything past 1/4 throttle and I can hear it, starts making the sound right at the same time I can hear my intake whistling sound. Threw the stock mufflers on last night so I could drive it around and listen to it. Changed the tune to bama 87 street to eliminate the detonation theory. Still sounds like an exhuast leak, which there is no way there can be one, when I drive by walls and give a bit of gas it is very audible like its an old chevy truck. I have read elsewhere that its just the thin stainless steel piping w/o cats letting noise through. What exactly does injector noise sound like??

Kevin509

I've heard that it might just be a sound made by the x pipe too, but I'd rather be safe than sorry. I plan on taking my car to an exhaust shop on Thursday that has always done right by me and get their opinion on it too. As far as injector noise, it's a clicking sound more than a metal on metal tap sound. Take a long handled screw driver and hold it against the injectors one at a time and put your ear to the other end. It should be pretty obvious if the sound is coming from the injectors.

06BlueGT

Ill give the screwdriver trick a whirl. Looked around on some other forums, seems some guys have the same problem and some don't. Always seems to be solved by putting stock h with cats back on, the cats must be able to mask this sound somehow. Its just annoying because I really like the x pipe sound and don't want to take it off, but the sound is really bugging me, sounds trashy like an old pickup. The sound is loudest at the downpipe right where it bends to become parallel with the car.

06BlueGT

This is from the modded mustangs forum, 99-04 gt section

"the pypes is garbage

fitment is fine, alignment is fine, etc

the design of the x portion is what kills it, it produces a horrid *** pinging/tick noise. do a little searching and youll come across a bunch of info about it"

Maybe it is just the design of the pipe??? Makes me a little angry I didnt know this before I bought it, maybe ill save up and put it on craigslist and ask for a different brand for xmas.

Kevin509

That's interesting. And I agree, I wouldn't have got this pipe if I would have known ahead of time that it might make that sound. I wonder if a 'cut and clamp' h pipe would be the cheapest solution.

06BlueGT

I have a friend here who drives a 07 gt with pypes o/r x, he has the same problem I have, he always thought it was a leak, but took it to a shop and they couldnt fix the noise, he also has reassembled it to try and fix it but no luck. I'm thinking to either get a upr o/r x (which kinda scares me since it's cheaper than the pypes one) or just put my stock h with cats back on. One of my friend's 03 cobra just got a used upr x pipe and that thing is completely silent under the car and not to loud in the cabin either, all the sound is going out the back. I have emailed brenspeed and lethal performance about my issue to see if they have noticed this issue with the pypes o/r x on their installs.

Kevin509

Sounds good. Keep me updated on what you find out.

06BlueGT

Brenspeed emailed me back:

"1. You may be hearing the typical sound a long tube makes on a 3V. For
example I can put on a set of Kooks or Pypes headers on a 3V and here the
exhaust and a tick type sound. Some people have no idea it is there, but I
know what I am listening for. We may not be talking about the same thing
though. Headers do make a louder noise almost like an injector tick, but
again we may not be talking about the same thing.

2. Exhaust leak. As you mentioned that can make a tick. If the shop has
looked everywhere than I am guessing you do not have a leak. There is one
other place to look. One time we had a set of headers leak at where all 4
tubes came together at the collector on the side towards the front of the
car. So basically if you held a lighter to the side of the collector facing
the front of the car where the 4 tubes welded together we found a small pin
hole dead center in the middle of the 4 tubes. I have seen this on two
different brands of headers. You may check there if you have looked
everywhere else."

I replied telling him I did not have LT's and only have the o/r x, so his reply was:

"Oh no headers.... Well I am not sure what you are hearing. If you say it is a tick it should be a leak. When you installed it did you use those little round metal pieces that drop into the pipe and help it seal it against the manifold?

Headers usually make the noise as they are thinner than manifolds, and you can hear natural exhaust sound in the tubes that stock manifolds hid. If you have only an X or H pipe and hear a noise I would say it is a leak, a very small one. Again though if I were in the car I would likely know, but I am guessing on this end as I have not heard it.

THANKS"

06BlueGT

I got this wild idea today that maybe it is leaking like at the welds where the two pipes come together to form the x crossover. Ill check that out tonight.

Kevin509

Sounds good. I was gonna take my car to the exhaust shop here tomorrow to have them look at it but we're supposed to get a couple inches of snow tonight so we'll see. I wish I new somebody around here with a different brand of x pipe on their car that would let me swap with them for a minute to see if the sound is still there.

Also, what he said in the email about headers being thinner than stock manifolds and therefore allowing more sound to pass through seems like it could apply equally well to the x pipe...