The high pitch 6.0

[majek5]

I bought the truck in Sept of 2010 coming from a 97 7.3. The truck already had a 4" turbo back on it. Had a high pitch noise then, not knowing if that was how the 6.0 sounded, just drove it. This summer I did the oil cooler, EGR delete, STC, dummy plugs, standpipes, blue spring, 6.4 banjos, ect. I already had flushed and filled with CAT ELC. When I installed the new up pipe for the EGR I noticed the downpipe had a small hole where it was welded to the next pipe. So my question...would this cause the high pitch noise? I looked for soot thinking it could be the y pipe, don't see any anywhere. I know the connection to the turbo is aligned and tight. I do have an exhaust smell on start up in the cab through the vents, which makes me think it is the y pipe, but why NO soot. BTW, haven't used a drop of coolant, no puking, and did replace the degas cap.

[fixxxer-upper]

My truck had a leak at the left exhaust manifold to the turbo intake Y pipe. The previous owner must have tried to remove it at one time and gave up. The bolts were loose and there was an 1/8" gap at that connection. I tackled that repair when I had the engine torn down and the replacement Y pipe was in hand. When the old Y pipe was pulled and inspected, there was an a leak in the braided sections of the pipe as well.

[GregsSD]

Yes, a small hole or crack in the up-pipe will make a very high pitched squeal.

My truck has been doing that for awhile and I tracked it down to a split in my passenger side up-pipe.

[majek5]

Originally Posted by GregsSD

Yes, a small hole or crack in the up-pipe will make a very high pitched squeal.

My truck has been doing that for awhile and I tracked it down to a split in my passenger side up-pipe.

The hole that I know about is at the bottom of the downpipe where it meets the next section of pipe.

[Ripping Trends]

Does it only happen on a cold start up? Mine has started making a strange whistle on start then goes away..

[440MOPAR]

mine does it just about every start up . its about five to ten seconds after fire up ..?its simultanius with the turbo vanes closing ...chripppp