hey guys, my car has been running on the same set of stock turbos for a little over 140K now...i thought they were replaced when the engine was rebuilt at 100K but i found out later the shop just used the same turbos. at what point do the original turbos start loosing their power and not pull as hard? i bought the car when it was at 130K, so i'm not sure if what i think is full boost is truly how good the stock turbos are supposed to be. it still seems to boost 10-8-10 just fine. thanks!

 

try getting a boost gauge installed, that way you can determine wether you are getting full boost or not.

 

From what I have heard the turbos usually go around 70,000 miles. I seem to be in the same place you are, my car has 110,000 miles on her ( probably something close to the kilometers you have if you convert it), and I don't think they replaced or rebuilt the turbos when the engine was rebuilt 30,000 miles ago, so they have from what I know gone about the same service life as you.

Just like rotarydreamz said, get a boost gauge, and make sure your boosting 10-8-10. That was what I did because it seemed my turbos were going, but they are boosting fine so for now they will do.

edit: I just re-read your post, and it seems you do have a boost gauge, and your are boosting 10-8-10. Really as far as I know there doesnt seem to be any other way other then that to tell if they are still good. I guess you could check when they are coming online in the rpms (what rpm you start boosting with the first turbo, and what rpm you start boosting with the second turbo) and compare that to others but I am not sure if that would prove anything, just an idea.

 

Typically something else will fail in the control system before the turbos themselves. If you are making the proper 10-8-10 boost pattern with decent spool and no weird noises you have a problem elsewhere. Normally the turbos will begin to push excessive amounts of oil through the intake, exhibit shaft play, and eventually the bearing will fail.

 

So even if you are still getting 10-8-10, and it seems to boost fine, with these kind of miles it is just expected that there is still something else wrong with them?

Sorry to threadjack, but if this is true then that gives a whole new perspective on my turbos, I had a local tuner dyno it and check over the system, and he said it was fine and boosting 10-8-10, but if I understand you correctly, I still have alot of things to check.

 

Isn't this pretty simple? IF the turbos still provide nominal boost, which the OP has indicated they do....they are fine.
Turbochargers are pretty hearty animals, all in all, and can take many years/miles/hours of use....just not much ABuse. Think of the turbos on the big rigs that have 1,000,000 miles or more on them.
So, I would say to the OP, what is your REAL question here? Are you experiencing a power loss? Or are you just not sure if your car performs the way it should?
The way I read this, your engine only has 40K on it...it should still be fine.
You could always get a compression test done if you feel something is amiss. But I don't think your turbos are hurt, from what you have said.

 

I agree. They are one of those components that either work or don't. Aside from oil seal leaks there isn't much in between working flawlessly and a wheel contacting the housing.

Alot of people don't understand that shaft play is normal since they use float bearings. A brand new set of these turbos has shaft play. Between that and the compliacted boost system I'd imagine that alot of boost problems are misdiagnosed as the turbo assembly itself.

My turbos were fine at 130k, but I replaced them with a low mile set that I rebuilt.

Despite all this, one of the turbines can easily be shredded by a blown apex seal being thrown into it.