sounds like an exhaust leak to me, but what do you think?

 

I can't tell if that's an air leak noise or something loose / banging in the valve train.

Are all the exhaust manifold studs still there (as opposed to a broken / missing one)? Does the manifold gasket look burnt? Have you removed the valve cover to check the cam, valves, & springs? What do your spark plug tips look like?

 

thats definitely an air leak, have you made sure all of your spark plugs are tightened down all the way? and i would look around where the exhaust meets the exhaust manifold, or some of the rear exhaust ports.

 

from what i've seen it doesn't look like any studs are missing but it's possible they could be loose, unlikely, but possible. the gasket between the manifolds and the head doesn't look in too bad of shape from the top, but the bottom could show differently.
i'm going to look a little further and see what i can find.

 

i've pulled the spark plugs and it looks like cylinder #6?, the one all they way to the front of the engine, is not firing properly.

 

 

 

That's cyl #1 (at the front of the motor) and was that spark plug loose? It looks like it wasn't even screwed in. Also... throw those crappy champions in the trash and buy NGK's (the spark plugs you are supposed to use).

Keep digging... might want to take off the valve cover to inspect...

 

i had the valve cover off and all seemed in order, i was curious about the spark plugs too. every other car i have i use ngk's. and yes that spark plug was tight.

 

Sounds like an exhaust leak at the head pipe where it bolts to the manifold. And yeah, NGK. Looks like they were all firing but oil fouled.

 

head pipe? what is a head pipe?

 

some information that would be very helpfull if you posted it as well.

http://forums.hybridz.org/showthread.php?t=149769

i would look for holes in the exhaust and loose/broken exhaust studs. or a cracked/rusted exhaust manifold.

forgot to add, check where the turbo bolts to the exhaust manifold.

 

WTF?! It's turbocharged? Naw... that's not important info....

EDIT... wow, I bet that thing runs lean!

 

i didn't think it was necessarily important to mention the turbo, because the sound is coming from before the turbo, but yes. it has a BAE turbo setup on it.

i bought a new exh./int. gasket, and ordered new ngk plugs i will probably dig in tomorrow and see what the old gasket looks like, are these exhaust manifolds known to crack and leak?

 

also, i know in the pictures in the other thread there are no clamps on the charge pipe from the turbo to the TB, but that's not the problem. I had pulled the pipe to clean it up a little and didn't put the clamps back on right away.

 

The head pipe is the one leading from the exhaust manifold to the cat or muffler. In the turbo car it would be the downpipe after the turbo. Your wastegate could be partly open. I think it's the manifold gasket on the bottom where you can't see it.

 

I doubt a leak after the exhaust manifold would sound like that. A leak down the line would be more consistent as all 6 cyl's are pushing air out, not at the same time obviously but more rapid then that if you get what im trying to say. Sounds like 1 or 2 of them are pumping out...Did you try just feeling with your hand around? sounds like its pushing out pretty good I would imagine you could feel the air hitting your hand. My friends truck made exact same noise one of his spark plugs would twist out a bit and the air would get by on compression stroke.

edit.
Not many cases of them cracking, biggest issues were bolts breaking off and the manifold simply separating from the head a bit.

 

if its getting that chugging sound its coming from before the turbo, as you would hear the turbo spinning when he revved it up.

 

i can't feel the exhaust leaking from anywhere, but mainly because the fan is also blowing air over the engine, i'll have to hold the fan from spinning and see if i can feel any difference, i've picked up a new exh./int. gasket to replace the existing one just in case. maybe it wouldn't be a bad idea to pull the manifolds and take a look anyway.

this turbo does not have a wastegate, i'm lead to believe that the BOV looking thing on the end of the charge pipe controls the boost pressure.

 

i would HIGHLY recommend using ARP studs on the intake and exhaust if your pulling it apart and are going to put it back together.

 

are the bolts known to break off inside the head? or just snap where it's still possible to remove them without much difficulty?

 

They're known to stretch (and you're running smaller n/a head bolts on a turbo setup). They stretch under pressure (boost) which will blow your head gasket in a split second. Good times....

 

i'm not planning on needing to pull the head, hopefully this isn't a head gasket.
can anyone point me in the direction of the arp studs for the z? or can i find them on summit's site?

 

uhh please don't do this... saw a guy at work almost get his arm ripped off by a fan luckly his coveralls tore off and didnt catch the hand.

And from my experience, the ones that broke off broke almost flush with the head always. I had to drill some out, some I got out with an extraction set. As far as studs go I went with a kit like this

http://www.summitracing.com/parts/AR...6/?image=large

 

haha, i didn't mean to hold the fan with my hand, i meant to put a clamp on the blade and block it against something else to prevent it from moving, the clutch will allow it.

and thanks for the link.