snw blue by you Posted June 26, 2008 Share Posted June 26, 2008 I've got one I can't pinpoint the noise on. F450, 12K, ZF6. It has a pretty constant hiss which at times will get louder then go softer again with no apparent rhyme or reason. Engine sometimes also seems loud and rattly. Performance is diminished somewhat but the turbos are capable of making boost just not very quickly. When I hear the hiss it does not appear to be coming from any of the sealing areas. Nothing in OASIS, anybody hear or experience this? BTW, on my roadtest I noticed a large amount of smoke (smoke, not steam) coming from under the hood as I was stopped at a light, pulled over and checked, NOTHING! Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted June 26, 2008 Share Posted June 26, 2008 I've got one I can't pinpoint the noise on. F450, 12K, ZF6. It has a pretty constant hiss which at times will get louder then go softer again with no apparent rhyme or reason. Engine sometimes also seems loud and rattly. Is this hiss during a road test, or also heard at idle? Can we point toward intake leak or exhaust leak? Performance is diminished somewhat but the turbos are capable of making boost just not very quickly. When I hear the hiss it does not appear to be coming from any of the sealing areas. Nothing in OASIS, anybody hear or experience this? BTW, on my roadtest I noticed a large amount of smoke (smoke, not steam) White smoke, I assume? coming from under the hood as I was stopped at a light, pulled over and checked, NOTHING! OK, just thinking out loud here. With the amount of plumbing contained in this truck I wonder if we're going to need to devise some low tech method of testing for CAC leaks. I'm thinking of disconnecting the CAC at the throttle body and corking it off. (Plan B: If there's not enough wiggle room to disconnect the cold CAC tube, buzz the bolts out of the throttle body and insert a piece of blockoff sheet metal between the throttle body and the intake manifoild? The bolts are out in the open.) Disconnect the air cleaner hose from the LP turbo and put a cork and air fitting in there, and pressurize the whole system to 30-40PSI. Would this work? Comments? /forums/images/%%GRAEMLIN_URL%%/grin.gif Quote Link to comment Share on other sites More sharing options...
snw blue by you Posted June 26, 2008 Author Share Posted June 26, 2008 Bruce, The hiss can be heard while driving or while idling in the bay, I am searching it out with the trusty stethescope but can't pinpoint it because there is so much other noise, both from the engine and shop noise. The smoke was a whiteish/blueish color, like oil hitting an exhaust manifold but everything is clean with no obvious leaks. Quote Link to comment Share on other sites More sharing options...
snw blue by you Posted June 26, 2008 Author Share Posted June 26, 2008 Found it! Exhaust leak at the turbo inlet or there abouts, defineately loudest in that area. The noise is being pushed foward under the turbos so it sounds like it is up front and possibly an intake leak. Anyways, cab will be coming off so I can perform a better inspection and find whatever blew out. This truck also had the horseshoe blow out about 2K ago due to broken VC bolts, fun is. Granted it is piddly shit but WTF! How do you answer this question? "How come my truck keeps breaking down?" Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted June 26, 2008 Share Posted June 26, 2008 DOnt forget the turbo outlet gasket TSB... and I have seen ONE right side turbo up-pipe leaking at the flex joint just like a 6.0 y-pipe. Quote Link to comment Share on other sites More sharing options...
Tony302600 Posted June 26, 2008 Share Posted June 26, 2008 we've done about 3 Quote Link to comment Share on other sites More sharing options...
snw blue by you Posted June 30, 2008 Author Share Posted June 30, 2008 I have seen ONE right side turbo up-pipe leaking at the flex joint just like a 6.0 y-pipe. Ya mean like this: Here we go with the rocket science thing again. How many years has the flex pipe been in exsistience? It also appears that the EDOC flex is cracking as well. Thanks for the input. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.