Exhaust Leak

[sgg93]

I'm having trouble locating an exhaust leak. It is far louder underneath the truck than either in it or from under the hood. It's not like a blown manifold gasket where you just hear it tick when the one cylinder fires. It's almost constant, and only once in a while does it stop hissing. I know my turbo inlet housing is cracked on the flange, but what else would cause it to leak? As far as I can tell, there is no leak coming from the flange. Could a failing flywheel cause this? I'm on a warpath for that flywheel and I've been blaming all sorts of problems on it lately. Is a hissing sound one of them?

[ryandamo]

its really hard to tell if im not there but if your turbo has parts cracked thats a dam good start. Has your flywheel failed already? look for spots where soot is accumulating on the firewall and on the exhaust pipes, if its been happening for a while youll see some

[sgg93]

Well the turbo went ahead and split on the flange and a little bit up the exhaust housing. I'm hunting for one. May end up with a rebuilt unit, but I'd just as soon get one from a junkyard, since I plan to upgrade to a D66 soon anyway. I was going to do the clutch and flywheel the other day, but I managed to strip the 4th bolt I tried to take out (yes, the last one holding the driveshaft in), so I gave it up early. Once I get a chance to change the turbo (that's a little more urgent), and get the threads repaired on that and a new bolt put in, I'm going to be starting the clutch. After that, all I have to do for winter is do my brakes and put new locking hubs in. And get tires...but that's not work that I'll do...just a check to write. Now that I think on it...I still have fenders that need trim sitting in my basement to repair rust. Oh well...it never ends.

[sgg93]

Well, I went and bought the turbo yesterday. $300 for turbo, pedestal, and a good set of up-pipes. Pulled it all apart today and realized that my turbo isn't cracked. It was some sort of weird reflection off of a casting mark. So I put it all back together and started it to check for leaks all around the turbo. Nothing. Still hunting the leak...My truck was a northerner and it's got the rust to prove it. Fenders...fuel lines... Is it possible that my downpipe rotted out inside the foil and something is deflecting the noise? Odd because I feel like I have less boost now...

[sgg93]

Is there any chance that a failing flywheel or a worn disk/pressure plate could cause that sort of noise? It loudest on the passenger side near the bellhousing, and I don't think it's ball flanges leaking.