How long does a turbo last?

Maybe some of you have contributed to my thread "Time to shoot it". This is a continuation of that thread in a way as I believe that the turbo may be going out.

My rebuilt turbo (water cooled Garret) has been in there for around 90k miles now. I am not sure of exact mileage as the odometer is not working right now. I do have a replacement speedo to fix that issue. Anyway, as of late the boost gauge has not been going as high as usual. I am still getting boost, the gauge is just not going as high. Then last night, for the first time, I heard a bit of rumble coming from the turbo on deccelaration. Just briefly but not a good noise. I would say that maybe it is a bearing type noise but I can't be sure. The car is going in for some repairs next week but right now it may be getting more diagnosis than repairs. What is the life of a turbo? I have run this car hard for the last 90k miles. Is it time?

Also my tach started bouncing a couple of days ago. It gets to about 2.5k then just jumps up to 4k and then kind of back down and then up again. If it is just the tach I do have a replacement.

So next week I am going to have the expert take a look at the turbo. I had recently done the wiggle test on the intake side and it didn't seem to have that much play. However, there is quite a bit of oil both in front of and above the turbo and on into the intake. I wasn't sure if that was from blowby or the turbo. I was planning on putting new struts in next week but that may get put on hold. And just so people don't ream me for not doing all of this work myself, this is my only car and not only a daily driver but a car I use for food delivery (Chinese) because with the economy that is all I can find for work right now. I do a lot of the repair work myself but sometimes I need someone else to do the other stuff. And I finally found a good reliable mechanic after eight years of looking.

They can last 300k unless one of us gets ahold of them. Remember that the play you are looking for in your turbo is in and out more than side to side. Couple mil side to side and nothing in and out is what I look for in a junkyard replacement. Probably not the tach, probably the crank sensor.

edit: Turbos puke oil in the intake. If you're getting it in the exhaust or getting enough that you can actually pour it out of your intercooler then you have bad seals in the turbo. Also check that your pcv is clear, crank case pressure can help with oil where you don't expect it.

edit, edit: Make sure the turbo oil return is clear.

My ebay turbo lasted 5k? miles of hard driving. same symptoms. won't boost as high, makes noise. I can even hear mine scraping the housing when it spins down.

Just stopped ballerboosting one day.

Time to upgrade!

stock turbos properly taken care of will last quite a long time.

As for the tach I don't believe there is any crank sensor on an '84. Does the signal come from the coil or ignition? Anyway that is a new issue.

No intercooler on this brick either. The car runs on synthetic oil so that is one positive. I am not hearing the fan blades hitting the case or anything like that. Like I said it was more of a bearing type noise (sounds like a vibration) on deccelaration. Maybe it's not the turbo but the gauge has been reading lower. Still getting boost. The car goes in Wednesday but I just want as much info as possible before I take it in. I was hoping to put on the new struts that I ordered along with a tie rod end, ball joint, front rotors and pads, and a complete flush to Super Blue. But if the turbo is going out I may just do the brakes for now. I also have new hardware for the front calipers and all new flex hoses for both front and rear.

Rebuild it?

Well, I drove the car today and it didn't make any noise. It actually only made a very slight noise. So I'm not sure what it is. Could just be the heat shield on the cat for all I know. Owning this car is often a game of guess that noise. So anyway I just plan on doing the struts and brakes next week as I had already planned.

As for the tach, the needle jumps when the car is in neutral so it is not clutch related at all. That is what I thought anyway. I will drop in a different gauge that I have from a junkyard cluster and then see if that makes a difference. Where does the electrical signal for the tach come from on a CIS car?

It's not uncommon for turbos to go million of miles on Diesel trucks.

Turbo needs clean oil supply, working PCV system, little to none back exhaust pressure

Highest I recall was a non-watercooled T3 on an '86 740 that was smoking a little at ~285k...original owner, synthetic oil, long daily commute.

my 92 740 t has 338250 miles, original turbo.i'm doing my hg next week and will be rebuilding the turbo too .i can't wait to see how it will run after because it runs good now except for the leaking gasket.

Well after all of this I think that the alternator went out tonight. The battery idiot light started glowing and then all of the rest. I boosted to pass someone and then the light started to flicker. I managed to get home but the idiot lights were flickering the whole way. I'm pulling the gun out right now to go putt the brick out of its misery. Looks like I will be dropping an alternator in this weekend.

I just remembered that I still have an extra alternator that used to be in the car maybe five years ago. I think it still might be good. O' Reillys down the street will test it for free.

Does anyone think that this might be the reason that the tach needle was bouncing all over?

My 98 s70 t5 has 212k with the original turbo and no rebuild.

I rebuilt my 15g some 5 years ago so it would replace the broken-shaft stock one in my car. It still seem to be fine.

I'm sorry, not crank sensor, hall sensor.
edit: not sure on year, if it's 2.2 then it has it.