Hello, here is a video of the smoke I have and a description of the symptoms:
- no smoke on startup
- once heated up, white oil smelling smoke appears
- only smokes on idle and off pedal. No smoke on cruising or boost


- Crankase ventilation failure path: I found the PCV to be mounted backwards. It was boosting in the crankase. I quickly reversed it. Now the plenum sucks cranckase on idle and the PCV blocks air on boost. But unfortunately the smoke's behaviour didn't change at all
- turbos failure path: I'm about to remove them and have a look if it's oily before the turbos or only after. before removal, there is no oil in boost pipes and minimal shaft play in primary turbo. The turbos have 60000 miles on it
- oil control rings failure path: the engine had a rebuild 10kmiles ago. I don't exactly know what should be the oil smoke behaviour in a faulty oil control ring case.

 

That's a lot of smoke in the video. If you found no liquid oil (other than minimal amounts) accumulated in the ductwork to or from the intercooler, or in the intercooler itself, the oil in your exhaust is probably not from the turbos.

 

Nothing in the intercooler pipes
If I'm not wrong, oil in the intercooler pipe would be burnt in the combustion chamber, so smoke would be blue, and there would also be smoke during throttle ON. This is not the case. No smoke throttle ON and smoke is white and strongly smell oil. There is also a deposit of un burnt oil inside the tail pipes.

Last note. A turbo can leak on compressor side as you wrote, but also on turbine side, oil going directly through exhaust.

 

I'm leaning towards turbos. The o-rings in the oil control rings typically smoke a LOT of they are bad and they typically won't do it on a fresh engine.

I would go to the 95 style PCV setup - cap the nipple on the upper intake manifold and cap the nipple on the oil fill neck that points to the left. I am suspicious of that PCV valve.

I assume you are also positive it's oil smoke and not coolant?

Dale

 

Thanks Dale. Yes it's definitely unburnt oil.
And as for the pcv I already tested the pcv/plenum route block off, as well as the "open oil filler cap" procedure with no improvement.
Even if I later confirm it's the twins (I really hope so), I will effectively consider definitely deleting the pcv plus associated plenum block off operations, only keeping the crankcase ventilation that sucks through primary intake

 

I agree. (I'm fixated on the leakage from compressors at the moment due to issues with my car and hadn't even considered turbine-side leakage.) But wouldn't this also rule out the incorrectly installed PCV valve as the cause of your white smoke? And rule out faulty oil control rings too?

Have you pulled the plugs for inspection? If they are wet and oily, wouldn't that indicate faulty oil control rings?

Is enough oil being lost to show up on the dipstick?

 

Hello,

No problem on plugs nor oil consumption

Here are my progresses:

Turbine housings inlets and outlet are black and dry. Not helpful... So I removed the manifold: exhausts ports are black and dry. So I plugged water and oil and started the engine: no smoke :-)

So I will separate the twins CHRA from the turbine housings, and rebuild the twins

One bad remark: there is water coolant dripping. And it doesnt seem to come from the plugged feeds. I'm a bit worried, This problem was not existing and I wasn't removing the twins for that. It drips below the sump, lets say in the area located at the limit of the front plate and the front housing. I can't clearly see where it comes from. It only leaks when engine is running.

Video

 

That coolant leak could be from the water pump. The water pump has a weep hole on it, if the bearings go out it will leak water.

Dale

 

damn... but why would it start to leak now? The water pump has been changed during rebuild 6000 miles ago.

 

I didn't know that . Must be something else then.

The water pump housing has a gasket between it and the block. There is also a spacer shim on the left side of the studs between the block and the housing, if this shim isn't there it will **** the housing to one side slightly and you could have a leak there.

Dale

 

thanks I will have a look

I will pressure the system to 10psi with a compressor to avoid starting the engine and try to look where it comes from.

 

60k miles isn't surprising for a set of original twins, especially if the boost has increased from even mild mods.

 

Coolant leak found

And sorted

Let's start rebuilding the twins

 

Edit double post

 

30 minutes of smooth head hammer friendly punches



The problem was definitely the primary turbo turbine oil seal. The back and the blades are coated with coked oil

 

Yep I think you found your culprit!

Dale

 

How are you going to fix that? De-coke it and replace the seal?

 

De-coke, rebuild kit balancing

 

My secondary turbo has a similar oil leak that recently got worse. I would like to see how you do the rebuild and balance. Can you post pics and info as you work through it?