if a turbo has oil blow by, how is that fixed?

[andrei1989]

i hear ppl saying that theyre turbo has oil blow by..what does that mean and how is that problem fixed? im looking to get a kit with 88k on it and i dont wanna run into that
any help is appreciated! thanks

 

[yudkib]

thought you were getting my kit! now im not helping you!

 

[andrei1989]

hey hey i just shoppin around man

 

[ScratchNSniff]

You never called...lol...

 

[KrayzieFox]

Blow by is when the seals start to go bad and oil gets past them (aka "blow by") into the housings. The result is usually either burning oil out your exhaust, oil in your intake/charge pipes, or both. And lots and lots of shaft play.

I would recommend getting a turbo with less miles. 88K isn't terribly high if it's a Garret, dual ball bearing and water cooled, but even then I wouldn't trust it cuz you don't know how the previous owner(s) used it.

Maybe they had a bad BOV installed and would get massive compressor surge at every shift, maybe they ran it really hard all the time and never allowed the car to cool down before shutting down, maybe they took out the restrictor and the turbo saw crazy high oil pressure, and the list goes on..

 

[littlemimus]

is oil blowby dependand on shaft play?

 

[yudkib]

how about this: is oil blowby even a real term?

it could have accumulated in the cold side due to actual "oil blowby" from the engine and our garbage PCV (more accurate use of the term)... its impossible to tell what he means without looking at the turbo. ask for a better description.

 

[Brian_K]

is oil blowby dependand on shaft play?

+1 anyone know?

 

[littlemimus]

ok let me better rephrase that. is oil consumption from the turbo due to the seals dependant on shaft play or can you be burning oil and not even have alot of shaft play?

 

[HondaEat-R]

For oil loss via turbocharger wear, there are only two or so options:

1) Your seals are going, and oil is pushing past the compressor seal into your intake pipe ( then some oil sits there and some gets compressed into IC pipes / IC), or the oil pushes past the turbine side seal, is burned in the exhaust pipes and shows as blue-ish smoke out of the tail pipe.

2) You can have a loose / damaged turbocharger oil supply or drain line, and lose oil like that.

Short answer: If any significant amount of oil is being pushed past the seals, you will notice some shaft play on the turbocharger.

 

[HondaEat-R]

how about this: is oil blowby even a real term?

it could have accumulated in the cold side due to actual "oil blowby" from the engine and our garbage PCV (more accurate use of the term)... its impossible to tell what he means without looking at the turbo. ask for a better description.

This is very true. But yes, "Blow By" can be used to describe oil pushing past turbo seals, though it's origin is related to piston ring "blow by". Although you need to specify, and not use them interchangeably.

 

[hornsfan10609]

My car hasn't run right since I got it last week and there was a small amount of oil in the bottom of the SMIC. I pulled the tube off and could feel oil in there, not standing or anything just a very small amount on the bottom of the SMIC, I couldn't find oil in any of the other pipes, is this possible blow by from the turbo? I have no idea on the previous owners but I'm sure the car has had it's fair share of beatings.

 

[HondaEat-R]

Define "run right". It's unlikely it's the turbo, but very possible.

Do you still have your valve cover vent line running to your turbo intake ?

 

[shane02pro5]

Pull off the inlet pipe to the turbo and if there is a puddle of oil on the compressor inlet the seals in the turbo are going bad causing turbo seal blowby.

Engine oil blowby put a filter on the crankcase vent and a millenia pcv with a catchcan run between it and the intake mani.

 

[yudkib]

ok let me better rephrase that. is oil consumption from the turbo due to the seals dependant on shaft play or can you be burning oil and not even have alot of shaft play?

depends who you ask. the only fail-proof way to see if the seals are gone is to visually inspect both the turbine and compressor housing for oil being pushed through the seals.

i took a turbo to a guy at a speed shop since i was worried about shaft play, and his comment was, basically, shaft play is indicative of nothing. you can try to get run-out specifications from garrett to see when its out of tolerance, but he wasnt convinced they even had a reliable way to measure it, and if they even had the specifications for a used turbo on hand. i dont remember exactly how he explained it, but basically, unless the turbo is BRAND new, there will be some play in the bearings. they seat themselves within the first hundred miles or so, and there will be a little play after that. so its difficult to gauge the life remaining on the turbo... his comment? use common sense to see if theres physical damage and check the seals.

so shaft play by itself doesnt mean much. a shaft that is out of alignment or has moderate motion will contribute to shorter life of the seals, but in most cases where there is minor shaft play, when the seals go, more excessive shaft play usually follows. so to answer all questions - based on my understanding -
you can have shaft play without having blown seals, but it may make the seals go faster,
and you can have blown seals without having shaft play - but not for very long.

are we all confused enough yet

 

[HondaEat-R]

i took a turbo to a guy at a speed shop since i was worried about shaft play, and his comment was, basically, shaft play is indicative of nothing. you can try to get run-out specifications from garrett to see when its out of tolerance, but he wasnt convinced they even had a reliable way to measure it, and if they even had the specifications for a used turbo on hand. i dont remember exactly how he explained it, but basically, unless the turbo is BRAND new, there will be some play in the bearings. they seat themselves within the first hundred miles or so, and there will be a little play after that. so its difficult to gauge the life remaining on the turbo... his comment? use common sense to see if theres physical damage and check the seals.

Bryan, I think you know that is BS.

 

[yudkib]

i never called turbonetics... obviously theres production tolerances for all the components, but he could be right about shaft play on a used turbo. a lot of those things are hard to measure anyways - how are you going to measure in-out shaft play on a compressor? and as for side-to-side, yeah you can use feeler gauges to check the clearance to the side of the housing, but two identical measurements could mean totally different things. on one compressor it could be normal wear-and-tear on the bearings, on another it could indicate catastrophic failure of the turbine bearing.
to accurately get any measurement of the amount of wear in the bearings, or to check any meaningful tolerances youre gonna have to crack the whole thing open. thats what the shop said and i have to agree - and if youre going through that much trouble, why not just rebuild it?
the only tests i could see being useful is on a bench test for turbos - one where they get the thing up to operating speed to balance the shafts and such. im thinking that could accurately measure bearing resistance and that may have specifications.

...but i will email garrett to see if they can give me some specs. ive been wondering ever since i went to that shop.

 

[littlemimus]

so then how do u know if your seals are done? oil in the compressed side?

 

[HondaEat-R]

As it stands right now, you're going to get conflicting advice on this. I'd go ahead and call either garrett, or a well known rebuild shop for information. Be wary of people misleading you though, as they may just want you to worry and send your snail in to be re-worked.

If you want to check the compressor side for oil leakage, you need to first eliminate the other variable that can put oil there, AKA remove your valve cover vent from your intake-to-turbo pipe. Clean any oil you might see right then in the compressor inlet and intake pipe, and reinstall the intake but NOT the valve cover vent hose. Go drive the car for a few days, with some hard pulls w/ boost. Check back on it and if you see oil pooling then it's likely you have oil pushing past the seals.

 

[shane02pro5]

I was able to measure in/out shaftplay with my calipers...depth from the comp housing face whille pushing in on the shaft and same while pulling on the shaft. You also have to realize when there is no oil flowing through the bearing there is more play. I had about .012" but it felt like alot more. This was with my IHI sleeve bearing turbo so quite different but still same...


^Yes there will be a puddle of oil on the inlet of the comp housing if seals are going bad and blue smoke in your exhaust.