Gents I'm a bit puzzled. I have had a tick for about 6 months now and finally decided to investigate. During a seafoam cleaning I noticed smoke pouring out the mani to y-pipe joint so I replaced the gaskets and still have a t
ick. Further investigating reveals that it only happens in gear above 1500rpm. It sounds like a diesel going up a hill so I'm leaning towards exhaust leak. Could the tranny put enough load on the engine to flex that joint? I'm going to try the yardstick stethoscope method tomorrow to narrow down the location.

 

I would tell you to cover the exhaust pipe with a rag while it idles, if you have a leak you will hear it blowing out under the truck.
But some one will come along and tell you, you might burn your hand.
or tell you to use a shop vac reverse, leave blower will work better,
all your best exhaust shops use leave blower & wet vac

 

Do sea foam again to see where it comes from, new gasket does not mean no leak think mines leaking still but my y pipe got bent a little

 

I will try both methods this weekend. I used an impact wrench to take the nuts off and on. Got a little nervous about sheering a stud putting the y-pipe back on so maybe its not tight enough. So if they are torqued to spec and it still leaks what do yall suggest? Also its weird to me that I only hear it when she is in gear. When she is in park and neutral she sounds good but in gear around 1500+ rpm it sounds like exhaust leak or valve chatter which the tranny shouldn't make those sounds.

 

Update... I did the induction cleaning again and found the leak from the manifold to head gasket.. Now waiting on parts booo. Also ordered a new steering gear. One thing I'm curious about is the head gasket on the left bank. It looks like the gasket is blown out but I have no symptoms other than minor oil seepage and the coolant tank smells of combustion but no coolant loss, no white smoke, no over heating. Im not sure if it is a gasket blowout or just a part of the gasket that is suppose to protrude. I did not see the same protrusion on the right bank