do the exhaust manifolds on our trucks have gaskets or are they machined to fit? if i listen by my turbo it sounds like i have an exhaust leak(sorta like a leak on a gasser with manifold gaskets that are blown). is this just the sound when the exhaust enters the turbo or am i in trouble here?

No gaskets from the factory....

so how in the world do i have what sounds like an exhaust leak from one cylinder? can you "hear" the exhaust going into the turbo? sounds pretty impossible to me. could i have cracked a manifold? i had a cracked manifold on my FWD mini-van but that one cracked from a bad motor mount. the motor was flexing too much and it cracked the manifold but that motor was turned sideways for the FWD.

could be your vacuum pump.

It makes a sound like pookata-pookata-pookata-pookata-etc, sounds something like a pump.

You could verify that by listening to it run without the belt for a short bit.

But then, a vacuum pump hardly sounds like an exhaust leak, and it really doesn't sound like you have ruled anything out, perhaps you do have an exhaust leak, crossover pipe, manifold, who knows, you are probably in the best position to find out.

just ordered a new DP, crossover, stud kit, and gaskets for the crossover tonight. when i bought the truck the turbo wasn't working(bad vac pump but i dont know when it went bad either). could this have led to a pressure build up and caused my "what sounds like exhaust leak". i didn't realize the turbo wasn't working until i put my boost gauge in. prior to the gauge i was driving it for about 2 weeks with no turbo. i'm wondering how long the previous owner drove it with no turbo. i ran the truck w/o the belt and its still there so its not the vac pump.

Which side do you hear the leak ? It could be the Downpipe where it connects to the turbo or it could be the donut gaskets on the crossover. The manifolds could also be cracked. That is not that unsual. The best way to find exhaust leaks on a diesel is to wait till it's ice cold then have someone start it and you be undeer the hood looking. The excessive smoke during startup usually gives away the leaks. My 2000 has a pinhole in the crossover right now that you can only see when the truck is cold. Another tell tale sign is black soot buildup. Unlikely that it is leaking at the heads unless someone ran the truck with missing ex manifold studs for a long time and it burned the sealing surface. I hate to say this but a headgasket compression leak can also sound like an exhaust leak but I'd eliminate the exaust system first.

if the head gaskets were leaking wouldn't i be losing coolant and having white smoke from the tailpipe? i'm getting the sound from the turbo side(passenger side). it seems to get quieter one RPMs go up. a friend thinks the sound of the turbo whistling masks the leak and i agree with him. the crossover is factory and everything else was pretty crusty under the truck when i bought it(it was a rhode island truck) so maybe i've got a small crossover leak or the DP to turbo clamp is a little loose? i'm not too sure right now as i can't get it on video too well as its tough to hear over the normal diesel rattle. it seems to get louder once the truck is warmed up. hotter exhaust making it louder? that sounds like a BS statement but i'm just guessing now.

My bet would be crossover pipe, have a look for soot or when cold try feeling around the joint between pipe and manifold while someone starts it. If it has been leaking here for a long time it can burn away the bolts securing the crossover to the manifold which could lead to breaking them during removal.:eek: