affirmation of fears

dark_knight

dark_knight

Member +
over the weekend, went on a sprint and was boosting a little harder than normal.. (given my routine driving habits) but at not more than 55 hundred revs. boost is currently set to 0.7bar. it was holding steady, no drama there. my worry came when i opened my hood today. my stock dump valve is set to dump to the atmosphere and it was evident that it had been coughing up some amount of black/old oil each time i let off the throttle at those high revs. i know it's old oil coz i only just did an oil change before the sprint so if it was coughing up engine oil then it would have been more golden than the black stuff that was being spat out.

so now,
a) is it that my turbo seals are gone/going..?
b) could i have some sorta other leak elsewhere..?

i have another ct9a sitting around but man, the work of getting to my current ct9b is just giving me quivers, esp since i've been feeling very lazy of late.. :p
so my question is, what could be going on under my bay..?
my spec list is: kakimoto exhaust, de-catted; blitz air element; stock TMIC; ct9b @ 0.7bar.
ideas..?
 
dac69er

dac69er

Super Moderator
probably the turbo seals passing a bit. clean out all your pipe work and keep an eye on it. one of my cars gets a little oily in the intercooler pipes. i just clean it ounce a year, its not that bad.
 
dark_knight

dark_knight

Member +
taking off the turbo

@ dac69er: isn't it supposed to be completely oil-free..? or that's only if you rebuild your turbo and plant new seals..?

also, now that we are on the topic, isn't it possible to remove just the cold-side of the turbo with the exhaust turbine exposed without removing the mani or the complete turbo from the mani..? i believe there is some sort of clamp that goes around the hot side that once undone should release the turbo (cold-side)..?

would someone confirm this please..
i'm avoiding taking my mani off coz i have the dreaded crack on bolt #4.. :/ & it may break off completely if i do..
 
dac69er

dac69er

Super Moderator
well, if you have a crack on port 4 then its probably leaking exhaust gas through that anyway.

in theory the cold side should be completely oil free, but a little oil in there isnt really a problem.

you can remove the clamp on the hot side will allow you to remove the complete turbo unit apart from the exhaust housing. it is usually a bit of a bastard to split there though ;)
 
dark_knight

dark_knight

Member +
crack

@ dac69er: the crack on bolt 4 is on the aluminium head and is miniscule. it whistles when the engine is cold but once at operating temp, i'm guessing the metal expands and it seals the crack.. won't worry too much about it until rebuild time..
 
corofin12345

corofin12345

Member +
if your using the stock dv then are you using the stock hose that comes off the top of the rocker cover to stock dv?? if so, this could also be where the oil is coming from.. new oil in old pipe will make it look old especially after dumping it out to atmosphere.. at high revs even with a breather filter on the rocker cover i noticed oil was coming out of mine, only small amounts tho
 
dark_knight

dark_knight

Member +
crankcase ventilation

@ corofin12345: that breather pipe goes to a catch-can. i'm thinking it's the seals in the turbo that's spitting some oil at high revs.. :/
i say so coz at higher rpm, oil pressure also goes up coz of the faster-spinning oil pump..?
 
Last edited:
Rob H

Rob H

Member +
The oil can only get to a set pressure due to the pressure relief valve in the bottom of the block so in theory the higher revs should not make any difference. I would think it would be more down to the higher temps in the turbo and the oil been thiner with the extra heat. I would just clean it out and keep an eye on it a bit of oil wont hurt anything. My peugeot TD leaks oil out of the intercooler it passes that much oil but it still keeps on going and its surprising how little oil can make so much mess.
 
dark_knight

dark_knight

Member +
thinner oil

@ Rob H: i hear you mate.. and your explanation is logical (turbo+heat=thinneroil) so i won't try and worry about it too much.. & yes, i can attest to how much of a mess a little oil can make. this one time, i had left my dip stick off as i was revving the engine. went for a very short drive with gentle revs but the mess created thereafter was just amazing.. :)
 
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