Hissing Sound, Possible Exhaust Leak?

[Rare40th]

Got the car out this weekend to take into town and come back and as I pulled into the alley way in which my drive way sits in, I noticed a hissing type noise that would follow suit with rpm's, when rpm's go up the sound went up and was very noticeable at idle especially in the garage.
I live about a mile and a half from a Grease Monkey and took it there to ask for their opinion(probably a bad choice on my part and a waste of time) and they got under it and looked and couldn't see anything and their response was "well it sounds like it's coming from the transmission".
My first thought was what in the transmission could possibly make that sound and nothing came to mind, especially since I could shift through all the gears fine and can't hear any other noises from the clutch or trans, I just had the clutch replaced last year.
I opened the hood and you can barely hear the noise, realistically all you can hear is the pulleys turning and then the fans coming on.
I got underneath and it seems like the sound is coming from where the engine and transmission meet, and I am beginning to think that the exhaust is leaking at the manifolds, since i have changed to off road x I have not replaced the gaskets nor did I replace the gaskets when switching the catted h on there to run emissions then putting the off road x back on.
Is it possible that it is an exhaust leak at the manifolds?
I am buying a catted h from a guy off of SVTP soon and am gonna take the off road x off for good and will more than likely replace the exhaust gaskets.
Sorry for this being such a long post I just wanted to give as much details as possible.

Here is a video I took, apologies to those for my car being dirty:
IMG_1195 | Flickr - Photo Sharing!

Thanks,
-Mike

 

[racermatt]

Are you sure it is coming from the exhaust? Hissing usually sounds like an intake or vacuum leak. It's kinda hard to tell without being there. Did you modify or change anything like a cold air or something

 

[Rare40th]

I have a BBK Cold air, 70mm TB, and BBK Upper Plenum. I do have a set of gauges from Glowshift in which one is Vacuum. Possible that the vacuum line for that is pinched?

 

[racermatt]

Maybe, but if you can hear a loud hissing I would have to say disconnected or possibly dry rotted cracked or cut.

 

[Rare40th]

I'll have to check it out when I get home. A vacuum line is the last thing I would've expected

 

[racermatt]

Well a vac leak makes more of a hissing then the exhaust. Depending where the exhaust leak is it will sound more like a tick. Its hard to say without seeing it though. Everyone interprets sounds a little different. Keep me posted.

 

[Rare40th]

I went through the vacuum lines including the one for my gauge and I did not see anything wrong with any of them.

 

[Rare40th]

Well I got myself a new project.......been chasing an issue with this thing since my emissions test back on July 26th. Gone through quite a few places, people and about 10 different opinions. Nothing was checking out, not the exhaust, or lifters, had the transmission rebuilt and new clutch placed in it, still nothing. Finish Line said a week or so ago that the exhaust was leaking at the clamps on my bbk x pipe and figured what the hell just go for it and see what happens. Got myself an appointment at 9 am this past saturday to get it in and get it fixed.......well Friday strolls around and got the car out and was gonna take the old lady to flat irons and have dinner and a movie........
Cruising down 120th everything's fine and dandy, up until this point I haven't done much with the car but cruise it around town, no more racing or hot rodding and just use it for what it's made for, anyways we turn onto Dillon Road that runs along Hwy 36 doing 35 mph, just cruising along having a nice conversation about my work and possible new job/company I am looking into buying out when all of a sudden.........POP!!!!! followed by loud ticking/fluttering. Soon after, the smell of raw gas is inside the car, so I pull it over and shut it off, look around and no leaks or anything, thought maybe at first it was a vacuum leak cause that's what it sounds like. No vacuum lines are unhooked or anything. Spend 15 minutes and at least 20 cars drive by without stopping, pretty sure a few of them touched my pant leg, at least it felt like. This car pulls over and ironically he works for O'meara Ford. Tells me it's my spark plug(#3 on the driver's side if you're looking at it from the front bumper towards the rear of the motor) Sure enough the coil pack is broke away from the manifold, and the spark plug is playing around in the head. Spark Plug blew out. Unfortunately it stripped the threads out on the head in that one and none of the others had issues. Got new parts and had it towed to O'meara.........well after about 3 hours I get a call from Nate who was doing the work and he says "well I got the new plug and coil in and new threads but this thing sounds like it has even bigger issues" So I get there and take a look, the FPRS failed(which I made a comment about to Nate when it got delivered by the tow truck on Saturday Morning but he said it didn't appear to be any of the issue) at the same time and was sucking fuel into the intake causing it to bend the rods in the cylinder that blew the spark plug out, also known as Fuel Locked. Another Ironic thing is the hissing sound I have been chasing was no longer there after the new plug and stuff was installed......
So Nate is installing a new FPRS and running a compression test sometime today when he's on lunch or whenever and is gonna let me know what he finds out and what all I'm gonna be looking at having to get done.

So now I have a question, especially since I'm not much of a mechanic expertise type of person but, where do I go from here? Just have oem stuff put back in it or look into upgrades?


****This is my post I just put up on my local forum****

 

[jymboslice]

if you bent a rod, then you'll need to rebuild your motor.

Do the compression test and make sure the engine is good to go. If it's not, then start saving for a new motor.

 

[Rare40th]

Got my compression test done yesterday and it came back good. 1st and 3rd cylinder were down about a 1% but other than that all of them were perfect.
Took a stethoscope and listened around at O'meara Ford and the noise is coming from the bellhousing area and looking at the dust cover shield on the transmission you can see where the fork was rubbing against it. I just had the transmission rebuilt not but maybe 3 weeks ago. The tech at O'meara thinks it may be the input shaft but it's making a rattle/metal clanking type of noise.

Ideas? Thanks a bunch.