PSD mystery problem

[Freight_Train]

Ok,Before the Brotherhood freaks out.This is for a buddy at work that is helping me out by loaning me tools(Big stuff!).Not in any way my rig....even though I will say it is stout and sound *******!


Ok,here goes.The other day he said he got down on it to pass someone and heard a sound.Said something was rattling around in the exaust pipe and got spit out the tail pipe.Said also that at the same time,the turbo changed sounds.Said it has a more peterbilt whistle(Rode in it and yea,MUCH nicer whistle!).Also,boost numbers are the same,The EGT numbers actually lowered by 200 degrees.Said before he could get it up to 1300 before he knew it but now won't get over 1100degrees.No power loss or extra smoke.Can't find any leaks.His truck consist of a 4" straight pipe exhaust system so not a chunk of muffler.Stainless pipe so not a chunk of rust.Not Ceramic coated no not a chunk of that.....You can definatly hear the whistle while riding in it comming from the front(but you know how mystery sounds can't travel all over a truck) but there are no noticable leaks or loose connections.

 

[Russ]

Must have sucked in a IDI Sorry couldn't resist.

 

[troutwest66]

What year PSD? 1st gen. no wastegate. '99 and up 7.3s have WG. I don't know if the 6.0s have the WG or not with the variable geometry turbo. First thought is a lost fin off the impeller of the turbo but I don't know if that would alter boost numbers.

 

[Russ]

Could be the EBV somehow came loose. That's would be the only thing after the turbo that could come loose and not tear the turbo apart, if he has an aftermarket exhaust.

 

[Freight_Train]

sorry,it is the last year for the 7.3L.he said the Back pressure valve kicks in like normal on cold start ups.Got me puzzled.No funky noises other then the new cool whistle.No vibrations.Been running for a week without exploding yet so who knows.Told him to pull the exhaust side and check it.That was my first thought but wouldn't a chunk big enough to hear rattling all the way back cause the turbo to be REALLY out of balance?Wonder if the nut came off the shaft?Oh yea,the new whistle kicks in around 15PSI and goes away around 25PSI.

 

[Mike]

Have him check the air cleaner to make sure he didnt cave it in.

 

[Muddinkev44]

Is his Pyro pre or post turbo, some downpipes come with a bung and a plug to tap your pyro into, could the plug of callen out? Did the band clamp break cause that would made a sound.

 

[geonc]

My whistle changed dramaticaly when I gutted the EBPV.....any possibility the butterfly busted I know but

BTW...if the compressor nut broke/came off.....there would be cyl/valve/turbo damage

Good point on checking the band clamp

 

[Freight_Train]

Well,he said he put his Preturbo,he checked the air filter first thinking he sucked it in,Said it sounds like the Butterfly is closing on cold startups,nothing has flown apart yet(that we have found) so we are lost......Just got a good fealing hearing something going though the pipe and the turbo changes sounds but doesn't Hiroshimas

 

[sassyrel]

still though freight--something inside the exhaust may have broken loose---