Interesting turbo problem

So my car started smoking over the weekend and then stopped and started and stopped... with a smell of oil burning every time you see the smoke.

So I think I have narrowed it down to the following:
Oil breather tank empty, not even a hint of oil - clean
Oil return not bent...
I have disconnected oil breather tank and problem persist, ie atmospheric ventilation on cam covers with breather filters on both sides.

I have done some research on the net and hopefully its not too serious...
I could have excess oil in the engine - never a good thing.
The return line could be blocked.
There is excessive positive crank case ventilation, pushing oil back up the return line, preventing oil from returning through this channel, thus oil could be pushed past the oil seals into the exhaust side of things causing the smoke.
Rings could be finished
Turbo could be shot

As a process of elimination I think I will drain oil first, change filter, clean air filter/replace, keep atmospheric crank case ventilation in place, only put in the exact amount of oil per manual.

Is there something else I should be checking, before I send the turbo away for repairs or replacement?

Turbo is less than 5000km old.
I haven't tested the oil pressure, but sure that is fine. Oil pump also < 5000km old.

Few questions:

Is it a stock T25?
How high do you boost it?
Do you let the car warm up and cool down when going for a drive?

T3/T4
Never gone past 1 bar
Always let car warm up and drive slowly when close to destination and then let car idle for a good 5 - 10 minutes

my car has been doing the same 😕 . . . i just assumed the turbo was shot 🙁
(still a "virgin" SX owner, so i haven't even considered any of those other possibilities you mentioned)

If you don't mind, i'm gonna "mirror" your process of elimination to see if i can maybe save myself the cost of an unnecessary turbo rebuild.

Always let car warm up and drive slowly when close to destination and then let car idle for a good 5 - 10 minutes

There are a lot of schools(opinions) on this topic.

If you drive slowly when close to destination, it should be enough. 5 to 10 minutes are a lot of juice waisted. We have water cooled turbo s. I don't think its wrong, but such long time is a waste in my opinion. I definitely warm up the sx from start on and take some time to get the oil warmed up as well.

Some schools(opinions) even announce turbo timers as a wasting of money and they only see bling, bling.

Some times I hate different opinions.

Chem 8)

When you drive the car is it ok, but when you stop it starts smoking, or does it smoke all the time?

Also you said its got 5000kms, is that from new new or since it was reconned?

My T3/T4 is oil cooled.

That is just it, and this is why I think its not rings or turbo... (and hoping)

It will smoke in first gear under boost, nothing in second gear etc. etc. etc.
So inconsistent.

And then at the next pull off no smoke at all under boost in 1st or when idling.

If you stand behind the car you only smell fuel (Very rich mixture).

You can see the oil residu on the bumper and only sometimes smell the oil if you had a hard drive with the car and the car is idling.

Sokar - I bought a brand new turbo 5000km ago.

And may I ask what oil you are currently using?

ChemCool wrote:

Always let car warm up and drive slowly when close to destination and then let car idle for a good 5 - 10 minutes

There are a lot of schools(opinions) on this topic.

If you drive slowly when close to destination, it should be enough. 5 to 10 minutes are a lot of juice waisted. We have water cooled turbo s. I don't think its wrong, but such long time is a waste in my opinion. I definitely warm up the sx from start on and take some time to get the oil warmed up as well.

Chem 8)

I don't mind wasting money on Juice.. I like the smell of petrol...lol... just as long as I cool the car down enough.

With a larger turbo it also does not spool as fast on idle as lets say a T2.5, so I agree that you only need to drive it at low rpm when close to the destination.

Castrol High Mileage. The viscosity per their website 20w 50, I think it was recommended above Futron.

I don't believe in those Midas or Autozone brands.

I have used Futron as well before - this was before my service though, which was done in October last year.

I believe in servicing at least once a year even if the KM's don't justify it.

Hmmmm ok, next thing, if you engine break (stay in 3rd down a hill, then take your foot of the petrol for a bit, then floor it) does it smoke hectically? Then it could be valve stem seals.

Reasons a car smokes:
Compression rings - oil seeps past bad rings - normally blue/white
Valve stem seals - oil seeps past bad valve stem seals - normally blue/white
Head gasket - Oil and / or water leaks in cyls - normally very white / light blue
Turbo seals - compression side - same symtoms as rings, turbine side oil is white and very thick (hangs in the air) as the oil doenst burn in the cyls, it gets heated by the turbo and blown out the exhaust

Thats basically all it can be..
Valve stem seals - cheap
Rings or HG - expensive
Turbo - expensive

Its like a white fog that hangs in the air - thus turbo per your list.

1 It could be seals
2 Its crank case pressure related... thus check items that cause positive crank case ventilation.

I am hoping it is too much oil in the engine.

How much would you say to have the turbo reconned.

I don't think I can do this because I believe everything in the turbo has to be balanced right?

Oh and Thanks Sokar
So now I can be added to your list of people that said thanks...

Normally when your rings are shot, your engine will start to breath heavy...

Personally when it suddenly starts smoking either turbo seals or valve stem seals

Thanks Vlade...

Speed breeder wrote:

2 Its crank case pressure related... thus check items that cause positive crank case ventilation.

although i think that its unlikely, i do think the following is possible:

i noticed that no-one has asked you yet, if you have checked the crankcase breather pipe that connects to the intake side tappet cover near the firewall??

if its blocked it will definitely cause positive pressure in the crank case. as for it preventing oil from draining - i dont know too much about this, but the theory doesn't sound false!

its a hard pipe, and it has a 90 degree angle built into it by the factory by welding two angle pieces together. it also changes its diameter drastically as it reaches the tappet cover. it connects to a pipe above the oil filter block.

its a real mofo to get out of there, in fact, you might have to remove the intake manifold, unless you are really dexterous! but when i rebuilt my CA18 - i found that mine was totally blocked with oil and grime. it took 3 acid baths to completely clean it out - it was that bad!!!

this also might be the reason that your oil catch tank is clean!!!

use it - dont use it...

but the other guys advice is also right!

thanks VC. I'll have to research this as I don't have all the original fittings and pipes.

I know the tappet cover on the intake side connects to the pcv, i'll check if there are as you say a welded pipe going down close to the oil block