Oh man.... I think I really screwed something up.

[sparks57]

Ok, the other day I took my turbo off to change out compressor wheels. I drove for a while, and every time I let off the throttle while making boost, I would get this "tist" sound from the turbo. I don't believe it was a bark, I think the wheel may have been slipping on the shaft because I didn't tighten it enough.



Anyways, I took it back off to replace the bigger compressor wheel (I didn't like the change I made) and notices small pits on the inside of the compressor housing that were marked by black sooty-like marks, along with some very strange irregular crack-like shallow lines in one area radiating out towards the edges of the flat area.



I also found small flecks of metal in the opening of the exhaust housing.



I inspected the compressor wheel and saw that there were some gouges from when I was tinkering with it (I had to pull in with a pair of pliers, I couldn't get my fingers on it well enough) and wondered if maybe the flecks came from metal that had broken off from the edge of the gouges, or maybe something happened when the wheel slipped, although my inspection suggests otherwise.



Power is fine, egt's, and everything is fine.



BUT: I now have an odd resonation (woom----woom---woom) at idle, and my oil pressure is down from normal. I ussualy read at the second line at idle, and third at WOT. Now I am reading a little below the second line at idle, and never get much past the line at WOT.



WTF just happened here?

 

[dpuckett]

Bad news, bud

The woom-----woom-----woom at idle could well be your oil pump. get a el cheapo gauge from Wally Wolrd, and hook the 1/8NPT fitting into the top of the oil filter housing. Pressure should be >10psi @ idle; >25 @ rated speed (near WOT). 1984 6. 9 made that noise for about 75mi before crapping out completely- at 70mph, no less. Gague didnt read abnormally low, jus made the noise, and then it dropped to 0, and locked up abou t1/4mi later. :{



Now for the turbo. I'm not real sure what to tell you abou that. I would say the cracks and scuf marks aint good, though. Was this on your hybrid, or the stock unit? Am I gonna have to send you my H1C? It has some endplay, but it made 28psi, and didnt scrape against anything. It's sitting on my desk right now.



Good luck, and dont go messing more stuff up, esp in your dorm room, or is this spring break?



Daniel

 

[sparks57]

I'm on spring break. It was my h1c compressor housing. The hx-40 compressor is fine.



The scuff marks only happened after I swapped the smaller compressor in. The strange surface cracks are on the newer turbo, on the flat plate the the wheel is recessed into.



Thanks daniel.

 

[BushWakr - RIP]

Hey CB, you really need to have that looked at by a specialist or an experienced turbo dude..... please be REAL careful if you intend to drive that truck... when either turbo lets go it's gonna get ugly darn fast... .

Hmmmmmm... . I never took a turbo apart and fiddled with it... later guys... I gotta go find nascar marks truck OH... and stop to get some pork chops for his dogs while I'm at it... .



PB...

 

[sparks57]

You've never taken a turbo apart??? They're really simple machines really.



As for "experienced turbo dude" I sent some pics to Dave Miller.



I just took it apart again and no more damage has been done. Everything looks fine.



Right now, I'm more concerned about thsi oil pressure drop and odd resonation at idle. I only hear it inside the cab... made me think it was the exhaust but it's never done it before.

 

[CDegner]

Your right ... turbos are really simple. BUT they are precision pieces of equipment. I've taken $100K pieces of equipment apart on a regular basis but I know my limits. I probably could do a turbo rebuild but until I have an experienced person to teach me and the PROPER tools to do it, I'll leave changing compressor wheels to an "experienced turbo dude".



A gouged turbine blade due to improper handling is a disaster waiting to happen. On the aforementioned piece of equipment that I work on, we have a pump called a turbomolecular pump. It spins 24/7 at a little faster than our turbos at WOT. It has machined titanium blades and is used to pull vacuums in the range of 10E-5 to 10E-6 torr. When one of them fails, it is catostrophic. There is nothing left of the blade but dust.



I'm glad it's your turbo and not mine!!



Carl

 

[SRadke]

Did you mess with the bearings in the tubo at all? If they are for some reason bypassing more oil with less resistance than before it may explain a loss of oil pressure in the engine. Just thinking out loud.



-Scott

 

[sparks57]

The "gouges" are just small marks on the end of the shaft that the blades come off of... nothing to be concerned about IMO.



Bearing? No.

 

[BushWakr - RIP]

CB... really just concerned that you may have a "malfunction" is all. . no other agenda or motives here...

I can get around a tool box and an engine but when things rotate at or over 100K I AIN'T gonna tinker till I know exactly what I'm doing... or... . unless it's nascar's then that's ok...



Now,..... CARL..... hey, hook me up with one of those bad boy's... I bet she'd lay some serious, nasty, church churnin, pew pounding, pump popping numbers with that baby... . yaaa... . Hook me up. .



Lets see... C-Ring, self tapping head studs inserted with a high E electron gun welder, triple pass welding on the head/block joint... hmmm... . what else we gonna need to hold this baby down...



pb.

 

[CDegner]

PB,

I think you would be SERIOUSLY disappointed in any results you had with the turbo pump. It has a flow capacity of all of 4 milliliters/minute AND it requires another vacuum pump on it's outlet to actually get the vacuum started. Under STP conditions, it might reach 25% rated speed.



Carl

 

[BushWakr - RIP]

Ahhhhhhhh crap... .

 

[cwienenga]

turbos

I haven't had a cummins turbo apart but when I was a cat mechanic we rebuilt air research turbos. I think the cummins are more simple in the bearing areas,however we used to have to check the shafts for being straight and just taking the nuts on and off could throw them out if not supported right. at these speeds ,something that changes the balance or runout has a drastic effect . changing housings is ok but most people would leave the center sections alone for these reasons.



cliff w

 

[hdm48]

Bob, one word,,,, concrete. Yea, that'll hold her down. Just open the hood and pour it in. 3-4 yards should just about do it. Might as well fill that big box behind the cab while you're at it.



About CB's turbo. I looked at the pictures he sent me and the marks looks like normal casting flaws after many miles of use. The soot spots in the compressor housing look like dust partical impacts and normal oxidation.

I told him to keep an eye on it just to be safe.

But, pictures on a computer screen are not the same as seeing it in person.





Dave

 

[Greenleaf]

Yep! There is a lot to be said for an experienced turbo dude. You go messn' round with the impellers and throw things out of balance and you'll wish you hadn't. Them things spin REAL FAST, an I ain't touchn' it.



Gotta go prepare the ceremonial smoke/burnt offerings for my new turbo>>>>>>>>>>>>>>>>>>>>>



-S

 

[Forrest Nearing]

been around turbos too much to be scared of them anymore... most assemblies aren't index balanced... the turbine wheel/shaft is balanced, and the compressor wheel is balanced, and you slap 'em together. I'm lucky enough to be friends w/ some guys at a turbo shop, so I check the balance on all my stuff, but I haven't found any OEM stuff that was severely out of balance.



CB, as for your turbo inlet w/ aluminum/dust particles on it? I've got an HX35 that looks just like that... it's a 200k+ turbo that still works perfectly. I thought the wheel was contacting the housing, but we eventually decided that it was corrosion from over the years...



I can't speak for a sudden change in oil pressure though. I might be inclined to put an upgraded turbo on there just to take that out of the equation.



Forrest

 

[nascar mark]

I ain't letting no Pastor touch my truck!!!

Remember I've seen you pick up a wrench once and that was the longest 5 mins that it took to explain to you which end is for what.

Besides if you did work on my truck, it would end up running like CB's truck. :-laf

 

[hdm48]

OOOOOO, I'm thinking I can hear the back-swing of PB's stick for that one.

 

[Greenleaf]

:-laf :-laf :-laf

 

[dpuckett]

Run for cover, boys. When the Pastor hits Mark with his cane/ stick, pieces of something's gonna fly all over the church.....

 

[sparks57]

Run like my truck??? Why I oughta!!!!! Watch yer mouth youngin!