So new issue now, I just did a whole host of crap to my truck chasing down a chirp under my hood under boost. New kx300x blew up in less than 200 miles, warranty it out no problems. had to buy new injectors, so I went from 238/80 to 250/80. Got everything in truck ran great but the chirping. Turbo went out, they sent a new one everything was fine on the test drive but blew a boot. So go back fix that and do a boost leak test and found i had a intake plentum leak. I tear the truck down again and do the reseal on the plentums, took the fuel system apart and drained the fuel bowl. Get everything done start the truck and its knocking like a banshee like it spun a bearing. I shut it off cycle the key a few times for the fuel pump again start it back up and knocking bad still. Rev it up some and knock got quieter, took it for a drive figured it was going to blow or go, gave it some ding dings on the road and the knock has damn near dissapeared but u hear it just cruising and on decel most can't hear it when your getting with it or at idle really anymore. When I first started the truck I though a rod was on its way out it was super violent and loud. Info on the truck, 01, 350ish on odometer, 6 speed, 250/80%, 300x stage 2, full regulated return, comp 910's, 4" down 5" back, napa 6637? Filter, fresh oil and filters everywhere when I did injectors. Maybe 200 miles at most since I did all this. Think it's injector knock? Or? Motor idles smooth and no missing or popping. No hint of a knock or anything before I did the intakes, I stuffed paper towels in each hole pulled and vacuumed out really good before I put intak runners back on.

 

Can you monitor Perdels?

What happened to the 300x?

Who built the injectors?

 

Sound clip would help a lot.
Small nozzles for 250CCs IMO,ever considered 200% nozzles?
I suspect an injector knock,tuning can make injectors super loud.
Is the knock loud when slowing down to crossroads etc..?
​What tunes?
​​​​​Also interested what blowed that KC..?

 

This is possibly a legitimate reason to check injector hold down bolt Torque.

Did you use a TQ wrench? What kind? What TQ?

 

Yes I can, with torque or car Guage

There was a casting flaw in the outlet
Also the charge wheel was hitting the housing, now only three blades were hitting the housing not all of them. They found a loose bolt in the backingbacking that looked like it was contacting the back of the charge wheel is what they said.

Unlimited diesel did, i almost thought it was injector knock but damn it was violent. i was making jokes that the bottom end was going to say bye after all this with my luck and about crapped when I started it and sounded like someone beating the hell outta the bottom of the motor with a hammer

 

I'm going to go start it here in a bit and maybe take a trip to th store in it and see what happens, if its making that noise on decel pretty good still ill get a video. Its very faint now except when I let off and the motor is holding me back. Or cruising seemed to be there. Not under a load, I cant hear it in the truck free reving any more.

I haven't, i live in oregon and run gearhead tunes and read anything over 100% needs live tuned?? So I did 80%, don't feel like driving 2000 miles or so to get live tuned.

I dono What blew the turbo, no contact marks on any wheels indicating digestion of something. When I hit boost and the turbo lights it makes a chirping noise, guessing just cause its the only thing I haven't done is manifold gaskets is the chirp but this turbo does it too so. But only after some heat soak will it chirp. Why the old bearings failed or the three blades hit the housing only is beyond me.

 

I smack them with a dead blow after i torque and then i torque them all again just to be sure,, dont really remember what i torqued them too been allot of bolts iv undone and put back in lately. I think 120inch pounds? Its a 3 year old snap on torque wrench. Think pulling it in the shop and letting it sit while I did the intakes a injector could loosen somehow? I just don't get it pulled it in the shop no knock or anything, motor ran great, start it after a real on intake knocking like a banshee.

 

Also, when I did injectors I did uvch, icp, fuel bowl heater, ebp, cleaned tube, new idler, tentioner, ps pump, belt. This last round was intake reseal which involved all the cross over lines being removed and fuel bowl drain, new turbo, and thermostat. Thermostat is leaking being as they gave me the wrong seal so that will get fixed today. Also passenger front head port for fuel was leaking so I took it out teflon taped it up again and reinstalled.

 

I believe Teflon tape on a fuel system is not advised but let’s wait and see what the others have to say.

 

probably not but it was on the pipe fitting that goes into the head. I made dang sure none of the tape went past the threads and could break off and go into the fuel void in the head. So I started it ths am, no notable knock just idling or reving so that a bonus, just went and got the correct gasket for the thermostate so ima get it sealed up and drive the dang thing. Hopefully just air in the fuel system in the lines running to the back of the heads? I dono, iv been needing to get rid of the parts for a while maybe its time. I got a buddy that has new ceramic coated manifolds and fire ringed heads, rods, and other misc things from his supercharged/turboed 7.3 he built a couple years back i could snag too if it comes down to a rebuild.

 

Teflon tape can be used - carefully. Not recommended because most people don’t do it right. Sounds like he understands the issues and should be fine.

I recommend anaerobic thread SEALANT like Loctite 545. Very forgiving and arguably better/longer lasting seal.

7.3’s don’t need fire rings with (36) head bolts.

 

Air in fuel or oil can make terrible noises!!!

 

So I sealed the thermostate housing up good today and drove to town and back. I still noticed a knock but ever so slightly, especially after getting to about 2800rpm and let off in 5th you can hear it knocking. Not getting any worse but not any better. Seems to run fine and you can't hear it when you free rev it. Think I might just take it easy on the ol girl and start looking for a lower mile 7.3 with forged rods or a cheap core and rebuild it. I really think something deep inside got messed up. I dono at this point. I hit about 34psi of boost a couple times on the way home an nothing got worse so hope it will be OK for a tinny bit.

 

it can take quite awhile for air to work out of the fuel, give it time and drive it

 

Ok, the only thing I get concerned with is the knock on decel when the injectors shouldn't be firing its knocking indicating to me its not injectors or air. Ambi wrong in thinking that? Also town is 30 minutes away after my 10min driveway. Takes almost 40 minutes to get to town one way.