Mr.NightHawk79

Yeah basically the science of it is... Incorrect fuel angle was causing the fuel to burn out of time and was likely still burning as the exhaust valves were opening up.. causing the woosh/puffing sound... Makes sense now, I think the head is usable but, better safe that sorry later down the road... I super appreciate everyone's input in this situation... Hopefully I can be of help in the future

Update: we found the issue after pulling the cylinder head.. #6 nozzle was not indexed correctly and was driven in, so it wasn't seated correctly and was causing the cylinder to misfire .. so the bore is ruined, new head will be here today. Noobs I tell ya 🤣

It came back from a run " concrete truck" running bad, we found two eups that were weak, it ran better but #6 still woofing... So we figured ok maybe#6 is weak too no change, then ok maybe it was the nozzle.. nada, tried another eup just in case we got a bum unit... Nothing... So we did notice alot of oil pumping from #6 rocker and went out on a limb and thought what if the dip/spike that rocker is pumping out is causing a spike and cracking a Jake ... Nothing changed after the rear rack was replaced and properly adjusted... So I think we're gonna be pulling the head tomorrow cause it makes sense

That's what we were thinking but the compression test and leak down were solid 390 we repeated the test several times.. we even did a 5/6 at same time to see if we were swapping compression but no luck there either

MACK E7, We are having a wooshing sound from exhaust only on #6 cylinder.. we have compression checked all 6 are 380-390#s with no leakdown, new nozzle, new rack on 4-6, ran overhead, does sound better but still puffing on #6 only, verified cam and rollers are all good, new E up and lines... Cracked one at a time only #6 doesn't change the rest it was obvious stumbling more ? I'm stumped 🤔