Refurbished K26/K27 hybrid turbo causing blue smoke

[Deception]

Hello guys,

I recently installed a refurbished K26/K27 hybrid turbo by Hoffer76 in my UrS6 2.2T which I bought from a forum member along with an STR exhaust manifold. As per the seller, the turbo hasn't been driven ever since it was refurbished which is most probably true because it looked new. The car is not yet custom-mapped and running on stock AAN injectors.
When the car is cold-started, there's a thick cloud of blue smoke coming from the exhaust. I was thinking that this might be due to badly refurbished gaskets on the hot side causing the turbo to burn oil. However, a friend of mine noted that oil could be getting through the cold side and entering the cylinders as it makes no sense for a cold engine that was just started to burn oil right on. This issue wasn't present before I installed the turbo.
The turbo was inspected and does not have an axial play. It seems not to have a radial play either.
Please share your thoughts as I am very close to getting a custom remap and wondering if I should go for it or spend 300 Euro to get the turbo refurbished yet again.

[Billman]

Use it for 400-500 km. I had this on my turbo after refurb. After a while it stopped. Maybe the seal rings need to settle in.

[Deception]

Did it burn a lot of oil?

[Billman]

no, but on every cold start up it gave a nice puff.

After 50km or so I made a trip and that was all.

[Deception]

OK, we're obviously talking about different things here... Upon being started, the car smokes for a couple of minutes, it's not just a puff

[Jamo]

Blue smoke is oil burnt by the engine, white smoke is oil burnt in the exhaust like a leaky turbo seal.

Assuming the engine runs on all 5 cylinders smoothly.

Blue smoke on start up is worn valve stemseals.

Blue smoke on prolonged idle is worn rings or worn valve guides/valve stems

Blue smoke on overun is worn exhaust guides/exhaust valve stems

Blue smoke under load is worn rings

Now you can also get blue smoke on prolonged idle if part of the breather system is gunked up as the system will pressurise causing oil to seep past areas that under normal operating conditions don't have any issues. But when the crankcase is pressurising start to fail. Symptoms of leaky rocker cover gasket and crank seals point to this. It is crucial this gets resolved sooner rather than later before any of the issues in the afforementioned post by myself become an issue.

http://www.s2forum.com/forum/showthread.php?p=628935

So it's not likely to be the turbo as the smoke should be white from the above

[fish]

Well when the turbo goes on SAAB´s (not if, when) blue smoke comes out of the exhaust anyway... Alot of it.

[bigcooler]

i always thought white smoke is water not oil

[pasbogdan]

At cold start a leak from cold side of turbo could not get smoke.The exhaust is cold so it could not burn the oil.At hot,hot side leak will get white smoke.Blue smoke means oil burned in combustion chamber.

[Billman]

I only had this issue when I changed the turbo. Everything else was unchanged. Happend a couple of times. And that was it. It was white with a blueish nuance.

Even if the car stands for 3 weeks I don't get anything now.

[Pat D]

I had this problem with my K26 yrs ago. I had it rebuilt and it would blow some smoke on warm up and dissappear after around 15min. The turbo place said its my engine, which was crap since it only had 45k on it. I removed the turbo and started it up, no smoke. I put the turbo back on without the down pipe, started it and watched small drops of oil being spurted out of the turbine while warmimg up thus causing smoke when the pipe gets hot.

I took it back to the turbo place again, after a strip down they told me the grooves where the seal sit were "ovalised" and so oil was getting through. They bored out the grooves and put oversized seals in. Wether this is true or not I don't know, but it did reduce the oil/smoke by 90%. I then used a 0-20w oil and the problem went away.

[Deception]

@Jamo:

This was very useful to know but as I said, the car wasn't smoking with the stock turbo so my engine should be out of the equation. Besides, I have a coolant leak from one of the hoses that goes in the turbo and the smoke is white.

@Pat D:

What you say makes sense. My old turbo didn't cause any smoke. I started up the car yesterday and observed the following:

1. Car started. No smoke during the first 15-20s
2. Blue smoke starts to come out of the exhaust progressively
3. After a couple of minutes smoke starts to gradually disappear

I was told that the reason for smoke to disappear gradually is that when the car stops, the residual oil in the turbo flows down on the bottom of the hot side. Upon next start, this oil gets burned when the turbo gradually gets hotter. The question is whether the turbo gets hot enough to burn oil in the hot side only 20-30s after start.

[Billman]

Castrol 10-60 oil has a flash point of approx 205 Celcius. Even the first pulses of exhaust gas are hotter than that. They get colder while travelling through the cold engine and the cold EM/turbo but still they are hot.

[Deception]

What if I dismount the turbo from the car - will I be able to assess what the issue is with 100% certainty?
Also, do you think I should go for a remap first and then refurbish the turbo if it doesn't stop smoking? The reason I want to go for a remap is because I am not entirely confident that I will be completely satisfied with this setup. This hybrid may spool way up higher in the revs than the stock RS2 turbo and I may decide that a refurbish work is not worth it. On the contrary, I don't want to take the risk of damaging the engine by driving it like that. I don't know if and what the exact risks are but the remap guy is 250km away from where I live and I am currently driving the car on an everyday basis.

[simon20vq]

Did you use new gaskets to seal the oil and water hoses to the turbo? Did you put silicon on them?