5 turbos in 18 months - what the???

I have posted previously about my turbo problems but now it has gone way past ridiculous. April last year I had a screeching noise which my mechanic said was a turbo. He put a new Billet turbo in and it lasted till early December when I replaced with another Billet turbo (under warranty). This new turbo lasted 5 weeks so I had the vehicle towed to Nissan dealer at Wagga who said they checked everything and replaced turbo with OEM Garret turbo. This new unit lasted 4 months and when it blew, so did the engine. New local mechanic put a new engine in it, new injectors and new turbo, harmonic balancer etc. Took two weeks but they said it is likely something in the old engine was causing the turbos to go.
Drove from Nelson Bay to Singleton (about 120km) and the new turbo has died. Mechanic says there is obviously something wrong with Garret turbos. Garret say obviously something wrong with installation.

I say

that sounds very unusual for this many turbos to blow in that short time, wonder if you have a turbo boost unit fitted and don,t know it ? could be running on a very high pressure for this to happen i would think. Garrett are a very good known brand of turbo by the way.

one that i've seen before is fuel leaking into the oil. turbo bearings are typically the firs to go. get the oil tested.

pre turbo intake restriction especially intake tubing that sucks in.
manifold or intercooler leaks, or turbo vac control unit. causing excessive turbo rpm.
high intake temps. even squished after turbo pipe can do it.

one problem variable setups have is the boost sensor is not at the turbo. so a leak will cause the ecu to spin the turbo faster. a restriction between turbo and sensor can do the same.

No chip fitted. When one of the turbos was replaced the mechanics there said I should have the boost checked and my mechanic said it was fine.
But I am interested to know if this can be adjusted via the ECU and if so, how would you know. Would this be information that any mechanic could read from the vehicle computer or would it be one of Nissans hidden codes only accessible by Nissan dealers computers.
Also I was told that problems inside the old engine may have caused the turbo failures. But this is a new engine and turbo.
Is it possible that incorrect fitting may be causing the problems?

tweak'e said:

one that i've seen before is fuel leaking into the oil. turbo bearings are typically the firs to go. get the oil tested.

pre turbo intake restriction especially intake tubing that sucks in.
manifold or intercooler leaks, or turbo vac control unit. causing excessive turbo rpm.
high intake temps. even squished after turbo pipe can do it.

one problem variable setups have is the boost sensor is not at the turbo. so a leak will cause the ecu to spin the turbo faster. a restriction between turbo and sensor can do the same.

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Fuel leaking into oil may have been cause for previous failures but this is new engine, so unlikely.
Has all new hoses and tubing. New exhaust manifold and new gasket kits on both exhaust and inlet manifolds. I don't know about the vac control unit but will ask.
Intercooler was flushed and tested and fitted with new hoses etc.

Where is the boost sensor and how do I test it. Is this readable from engine computer?

i would assume a obd2 reader would display the boost.

i would pressure test the turbo and pipes. its just a fitting to fit on the turbo so you can put compressed air in and pressurize the system. makes leak testing easy.

Boost sensor is low on the right hand side of the intercooler. ECU reads this and data is available in Torque as the standard OBD2 boost pressure value.

Turbochargers don't just let go like that, there has to be a reason. Has anyone examined a failed turbocharger and defined what part actually failed? Was it bearing failure, was it the impeller striking the rear of the housing (like it had been pulled through by the turbine) or some other failure? Coolant line blockage causing the unit to overheat, cook the bearings, burn oil in the bearings causing them to fail?

Old.Tony said:

Boost sensor is low on the right hand side of the intercooler. ECU reads this and data is available in Torque as the standard OBD2 boost pressure value.

Turbochargers don't just let go like that, there has to be a reason. Has anyone examined a failed turbocharger and defined what part actually failed? Was it bearing failure, was it the impeller striking the rear of the housing (like it had been pulled through by the turbine) or some other failure? Coolant line blockage causing the unit to overheat, cook the bearings, burn oil in the bearings causing them to fail?

Click to expand...

Thanks Old Tony. I should have had the vehicle towed to you or at least your mechanic, I am apparently not that far away.

Just sent the last two turbochargers to Denco Diesel for a post-mortem. The last turbo (No. 4) had no impeller - they found it in the top of the catalytic converter. The one prior to that was seized. Have not removed the current on yet as we just got towed back home.

It would not appear that the current turbo has 'cooked' as the oil is crystal clear, as you would expect after only 120 k on a new motor. I may be wrong but thought if there was a temperature problem sufficient to overheat to the extent of failure then the oil would have darkened.

Unless the previous engine had metal fragments that were killing turbos and then with the new motor this turbo died of totally unrelated causes, it would appear that something else is causing the problem. As we have a new engine and all hoses, tubing, pipes etc., my best guess is that the turbo boost setting is too high. I didn't know that this was possible without a chip but apparently it is possible to adjust the ecu????????? Or so I am told.

Of course I can't test or read OBD2 or test pressures until I put another turbo in. Might be cheaper to buy shares in Garrett?

try for a replacement turbo from Garrett, if its not that old they should replace it especially knowing its come off a 4 x 4 vehicle not a h.p. drift car.

Like Tweake said, if you had a new engine fitted and it went again it must be something ancillary that wasn't replaced, like the air intake. Otherwise your not shagging the neighbours wife and her hubby's lifting the bonnet and dropping metal filings in the oil filler?
Find out if they kept using the same oil feed and drain hoses, if they're blocked a turbo wouldn't last long.

or a crap mechanic who doesn't pre oil the turbo and fires up it dry. that will stuff it from day 1.

Just an update on the turbos. The first turbo that was replaced probably did not need replacing. The local mechanic said the noise was the turbo but it would appear from having the same noise later on that the noise was just a leaky gasket post turbo.
The turbo we first put in was a Billet turbo, so I thought, but it turns out it was just a cheap Chinese copy and only lasted 6 months. They replaced it with another that only lasted 6 weeks! I then had a Garrett turbo fitted by a Nissan dealer but when they fitted it they used some silicon sealant which got into the turbo and killed it dead. They also forgot to tighten most of the bolts (they were only finger tight) and before it died it blew out the gaskets making enough noise to drown out an FA18.
So, bad diagnosis, crap parts and faulty workmanship -and guess who pays?

the nissan dealer is to pay .

Time to start busting some heads.