Theory's On Oil Smoke From Under Bonnet

[PSI_GTSII]

Noticed after a track day last week.

Smoke 'eminating'(!) from bonnet on Passenger (Turbo) side after track session.

I did do an oil change before track day and slightly overfilled.

Still smokes after each drive, the harder you drive it the more smoke seems to appear (although I'd would'nt describe the amount of smoke as thick)

Has now started to leak oil onto driveway

No oil leak visible from top of motor

Have degreased underneath but nothing immidiately obvious, although could not see to well.

Turbos are reletively new garrett GT2560R's, less than 5000kms on them, no boost controler on my car so never worked to hard.

Air Filters are oil free.

I do not think the turbos are damaged, but suspect broken oil line leaking onto something hot down there?

Any ideas?

Cheers

Lindsay

[James_03]

yeah probably going to be oil feed/drain pipe somewhere.

Thats going to be fun to fix.

[PSI_GTSII]

Thats going to be fun to fix.

I know, nothings really easy on the RB26....I'd hate to own a VG30....

[djr81]

Lindsay,

This is usually one of two things:

1. Have you fitted a catch can to the oiling system? As often as not these smoke after a run on the track.

2. The oil feed or return lines to the turbo leak at the connection. Usually this is a complete bastard of a thing to find.

[N1GTR]

2. The oil feed or return lines to the turbo leak at the connection. Usually this is a complete bastard of a thing to find.

My old ones were doing that

Absolute prick to get at

When you try and fix it, make sure the car hasnt been running for AGES, i thought it would be cooled down and ended up burning my hand

[Beer Baron]

i would say if you re-used the stock lines then there is a high chance one of them is leaking. either at a turbo (where it screws in) or where one of the fittings is brazed to the pipe. sometimes these holes are very, very small and you will only be able to see the leak when the engine is running and the oil has thinned a little (with heat). try and pinpoint it first if you can. then replace the feed lines with custom braided ones. you can make them yourself if you are even mildly handy. just buy the fittings and hose you need (PTFE teflon, sheathed with stainless) and make them up.

Do not keep thrashing the car in the meantime as there is a chance one of your turbos will be being starved of oil as the leak is almost certainly from the turbo feed (under pressure).

[Snowman]

Are you sure it's not power steering fluid boiling over and then burning off. Very common with hard driven GT-R's.

[Roy]

OK, ok, ok. I dont own a GTR, but new aftermarket turbos and smoking...my 2c is "what was used for the oil return lines" ?

Sheathing and high temp silicon sheathing is your friend as i have cooked a scary amount of return lines, and seen plenty give up on the track. It comes down to the hose you use...as much as the age. I would think the std oil feed lines being metal woudl be very durable.

LOL...or Power steering, though i wouldnt expect it to be dripping onto anything that would allow it to be burning off???

[Godzilla32]

LOL...or Power steering, though i wouldnt expect it to be dripping onto anything that would allow it to be burning off???

Same goes for turbo oil return lines. They arent above anything hot that i remember. Pity too as they arent too hard to do while all still assembled..

[Roy]

True, but its bloody hot and very close to the turbo housings and i find it weaps and lands on everything. Mine was smoking slightly and again it seems it was the mist that was landing on everything and was burning off. In one case it wasnt really a split, but hazing/cracking which allowed ...you get the picture. LOL, and i never said i was right

[sav man]

Is there much of a benefit to run braided oil lines instead of the factory's metal ones?

Mine used to have a little smoke after hard driving, but I think that was cause one of front pipe gaskets were stuffed, and i think there was some leaking coolant.

[chrissso]

What about a head gasket that's leaking a bit of oil onto the manifold?

[Ronin 09]

when you're driving fast the oil off the lines could be flinging itself onto the dumps... last i checked they get mildly warm and *may* vaporise the oil causing smoke...

my front CV packing grease has decided it likes the look of the outside of the dump pipes more than the iside of the boot...

[PSI_GTSII]

I had a workshop change the turbos, but I would say it still has the standard Oil lines and return pipes on it, I am not sure how these run in relation to the manifolds, dump pipes or something that gets hot down there but will have a closer inspection on the weekend.

Short of employing the services of my 4 yr Old daughter to stick her hand up there and replace the pipe / hose I think i'll just give it to a workshop to fix...plus its just the excuse I need for a few more mods