another 3304 question

[coxy]

my buddy has an 89 518 and it pushing  oil out of the blow by tube I think its a lot but when you check the oil its fine about a 1/2 gal a week and its a vary vary hard up hill pull it doesn't smoke has lots of power  dont skip  never have had to use starting fluid any idea what will cause that thanks again 

[kiko]

Coxy,  blow by without skip comes from two places, pistons or turbo. If it has visible blow by at idle, remove the oil fill cap. Typically if the blow by is puffing it is coming around a piston and if it is just constant it is the turbo pushing exhaust down the turbo drain into the crank case.
 

[mike_belben]

Turbos are very easy to overhaul with basic hand tools btw.  Dont buy new if u can get a center section kit. 

[coxy]

interesting never knew a turbo would do that always thought when they was bad the only thing they did was dump raw oil out of the smoke stack would it be better to get the eng up to temp to check the blow by on filler cap or do it cold  thanks again 

[mike_belben]

Cold youll have more piston to wall clearance.  

The turbo has to be run up against a load to make boost pressure in the compressor and exhaust back pressure in the turbine.  If the sleeve seals in the center section [called a CHRA] arent holding youll push pressure into the shaft housing and down the oil drain. 

Very worn valve guides also add a good bit of volume to the slobber tube.  That engine may be old enough to run oil shields instead of oil seals on the stem.. Im not sure.  Shields will leak more compression up the stem and into the valve cover.

[coxy]

 up date on the oil leak dropped the belly pan and found 2 of the oil pan bolts loose loose one was right by the blow by tube it was weird that that much oil would squirt out around that bolt letting it push it up by the blow by tube making it look like it was coming from there I have had some strange thing happing to me the last few months but glad it wasn't something major  again thanks guys for the help