When to retire stock turbo

I've reached 225k miles on my original BW kp-39 and it's still running strong even with an rc1 tune. I consume a liter of oil every 10k miles, but otherwise no boost creep, bad noises or problems. I know these get a bad wrap for longevity, but most of the miles on it have been easy, very low boost highway miles on cruise control and not a lot of heat cycles from small trips. Also garage kept and no road salt exposure

Will there be any warning signs of impending failure? The last thing I want is a sudden death and unexpected runaway. I've tried to only justify big purchases with actual need or maintenance intervals, so despite wanting more power I've avoided upgrading to a vnt17.

I have a new sbc smf daily clutch kit installed recently so I'm ready for more power. I guess the question is, at what point should it just be retired despite working well or for someone who is in tune with how the car runs will I have adequate time to detect failure?

Check the shaft play if you are concerned about it.

if you are not craving more power i would just run it till it starts giving issues. Higher oil consumption, boosting issues, noise. Then be prepared to replace. but if its going strong why sweat it. Would not hurt to do an inspection of impeller wheels and feel for shaft looseness in the bearing.

Thanks all, I will check out the internals next time I'm working under the car. I am craving some more power, but right now I get 51-53 mpg and would rather keep that over the power. Not sure if it would change just cruising on the highway with upgraded turbo and tune...I assume not that much.

there are plenty of stories of sudden-death, so IMO, checking for shaft-play or oil and then making a guess as to it being good for X many more miles is just that, a wild-ass-guess. of course, if oil consumption goes up or it's having boost issues, then be on high alert and ideally replace immediately. if it were me, i'd press my luck a bit longer and run it through the winter and plan to do a turbo upgrade in the spring + any other goodies.

unless something hasn't been done right, modest (and even relatively aggressive) tuning doesn't negatively affect overall mileage if you keep the same driving habits.

You could upgraded the turbo and keep the stocker around if the vnt17 fails prematurely or if your going to demod and sell. Or you could just sell it to someone desperate for a good stock turbo to recover some 9f the vnt17 costs. Waiting for it to go bad is not good idea as it will likely lead to you spending more money than you want and be at an inconvenient time.

There is a difference between run to failure and performing normal maintenance checks of a piece of equipment
anything can fail at anytime. but that does not mean replace when you feel like it. There is no mileage limit set to replace them at so do your due diligence and keep an eye on it, bit be prepared to replace in a hurry if needed

SkyRyder55 said:

There is a difference between run to failure and performing normal maintenance checks of a piece of equipment
anything can fail at anytime. but that does not mean replace when you feel like it. There is no mileage limit set to replace them at so do your due diligence and keep an eye on it, bit be prepared to replace in a hurry if needed

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Im aware of that difference. I was mainly pointing out the value of his stock turbo is far greater if he were to replace it while still functional making the cost of an upgrade or stock replacment much cheaper. A tow or runaway is going to cost money plus the cost of a new turbo. How much more life can he reasonably expect out of a 225k turbo? 75k at most? I haven't seen too many turbos make it to 300k.

Somewhat different, I just rebearinged my GT1749V (VNT-15) as the bearings were letting the compressor wheel touch the housing if I put a tiny bit of pressure on the shaft. No significant thrust bearing play.
The new bearings almost halved the shaft play side to side.

Might stop a possible strike from the wheels to the housing, who knows. It'll probably die soon though. Just a little bitty thing.

How do you check the shaft for play?