turbo questions

[540s10]

how much side to side play is too much?

I think the seals in mine are junk,

I had both the upper and lower intakes off and cleaned them spotless o the inside, and have had the CDR venting to atmosphere since. I have oil in the intake now, and also it burns blue smoke when reved up in park, which takes a minute to clear away after its brought back to idle.

can't do any road testing as its not registered yet.

should i pull the compressor housing off and brake clean the impeller and housing to clean it up and then see if it gets wet inside?

 

[BigBlueChevy]

Blue smoke can mean there is oil being burned. Pull the intake pre-turbo and try to move the impeller back and froth as well as side to side. There really shouldn't be ANY defection at all, otherwise things start to rattle around instead of spin which causes more damage as time progresses.

If your venting the CDR to atmosphere then no oil would be introduced into the intake that way. However, the CDR is designed to vent the crankcase to keep pressure down in there. Reguardless of whether its a brand new CDR or 100,000 miles old if there is pressure inside the crankcase it will allow oil to blow by the oil and piston rings and into the combustion event, which could explain why your only getting blue smoke when "reving up".

Like I said, check your impeller for play as this could be damagin seals and hence throwing oil into the intake(which would explain oil in intake). if thats not the problem reconnect your CDR and see if the problem disapears.

 

[SmithvilleD]

Been looking for BorgWarner/IHI specs for radial movment & axial clearance (thrust bearing endplay), but no luck finding official service documents.

Just as a point of comparison, the Holset service specs for the HX-35 are:
0.013 - 0.020" radial play - measured w/ a dial indicator at the end of the comp wheel, just before the retaining nut.

Axial/thrust endplay was 0 001 - 0.005"

I realize they're not the GM-4 specs, but thought I'd throw them out as a data point.

FWIW - the radial play will often feel looser if a ctr section was solvent cleaned & put together dry w/o any oil - the oil in the clearances often makes things feel a bit tigher, as you'd expect.

Unlikely to be the cause in this situation, but I've seen installs where somebody forgot to remove the little red plug on a newly rebuilt turbo's drain. Since that plug is mostly inside the hole, it wasn't noticed & the drain flange got bolted up. No way for oil to drain away will definitely get some oil past the ctr section seals & smoking things up. Didn't cause any permanent dmg as they figured it out fairly quickly.