2 turbo's blown!

Hi People of Navara Forum
this is my first post even though i have been here a while sifting through the endless amounts of very helpful information.
I am wondering if anyone has heard of multiple turbo failures in their D40's?
I first bought my ute @ 50,000kms and blown its first turbo then again at 60,000kms blew another one. i really dont want to replace another one any time soon
a garrett turbo has been in the last 2 times as the mechanic said its the best for my ute. he seems to think its a computer issue. i have since christmas fitted a boost gauge and its PSI is reading way over 20 PSI, what is standard PSI for the D40 too?
i would appreciate any response as everyone i speak to has different theory's.
cheers ryno

A blockage in the turbo oil and/or coolant lines would be the first thing to check, the oil return line first and foremost. Low oil level/pressure would be a related issue as well.

The stock turbo can be taken to 22-23 psi without trouble, was the boost in that region or way higher? If its the latter, than it would/could be a turbo control issue indeed.

Lastly, one can abuse the turbo by turning the engine off right after booting the pedal, while the turbo is still red hot, but I doubt that even that would kill a turbo in 10000k....

My guess would be a blockage in the oil feed or return.

Welcome aboard.

As Bluenavara points out, stopping the engine (turning off the motor) after being at significant boost will stop the oil flowing through the turbo bearings. A hot turbo will cook the oil very quickly, and burnt oil forms a nice hard varnish. This varnish causes the bearings to form pits in the bearing surface or causes the bearings themselves to crack leaving the debris to complete the destruction.

I do think that severe abuse of the turbocharger can kill it in 10,000km quite easily.

To avoid this problem, you can do any (or all) of the following:

* Plan your journey to allow some gentle driving (about 2 mins is enough) before stopping.

* Purchase an EGT gauge and wait for the temperature to fall to an acceptable level before shutting down the engine. If the probe is mounted in the exhaust manifold before the turbo, I'd wait until the temp fell below 300C. If it's installed after the turbo, wait for the temp to fall below 200C.

* Fit a turbo timer. These are technically illegal because it is against the law to allow your engine to be running while you are more than 3 metres from your vehicle (this may vary between states). However, many use them and I've never heard of anyone copping a canary over it.

* Fit an EGT-controlled turbo timer. This is the ultimate - and not currently available unless you're technically inclined and care to combine two Jaycar kits (1200C temp gauge and turbo timer).

If the turbo has been replaced twice, I'd be dismantling the oil feed lines completely and either replacing them with new ones, or thoroughly cleaning them. These are quite critical. Also, being a D40, check the coolant lines - our turbos are cooled from the engine coolant.

Have you been letting it cool down before you shut the engine off. I leave mine until 10 seconds after I have seen the EGT gauge drop to 200C. Maybe Fitting a catch can and a turbo timer might be the way to go once you get it replaced.
I am not sure about the D40s but if you are able to fit a boost controller fit it, set it and you should be right. From what I have heard the D40s have variable boost so the engine determines how much boost is required according to the throttle. Maybe it could be a bad sensor or something along that line?

thanks guys, really appreciate your feedback.
my mechanic had said all of the above but still happening.
when the first turbo was replaced he cleaned out and checked the oil and cooling lines. they were fine.
the next time it happened he thought he did something wrong but he checked with is turbo supplier and says he's had a few similar cases where it over boosted and the compressor wheel becomes unbalanced and goes off centre that much it hits the housing and destroys its self.
we are talking a Garrett GT2056 what kind of PSI can they reach before failure?
i have heard turbo timer, ill start with that. i usually do drive like a granny before i turn it off and many times let it sit before turning off. i will be more vigilate of that now i know.
another thing my mechanic said might help is EGR blocking plate, he said it can cause overboosting in some cases?
cheers guys.

It's a gt2056? Ha, there's your problem! Those things belong on a lawnmower go kart, not a car. Get a larger turbo, like a t25 (or that area/series, try for a ball bearing instead of a journal bearing, though. Your rig probably doesn't run a BOV/plumback, so a ball bearing will help counter that).

You can't push over 20psi into a t2 type turbo. No wonder they're going down like flies. Just get a bigger turbo, you can find second hand/rebuilt turbos cheap that will bolt straight on, and do exactly what you need.

Otherwise, if you've only got 50k on the truck, can't you take the turbo back to Nissan and demand them to fix it?

Ok, if its not the oil and coolant lines, double check the max boost you see on your gauge. It should be 18-19 psi stock, around 20-21psi with an aftermarket free flowing exhaust and intake.

Anything over 24psi is cause for concern and points towards a turbo control issue.

Second point: do you have pics of the blown turbos and/or a detailed description of visual damage? Oil on the compressors side? Oil on the turbine side? Movement of the shaft? Chipped compressor and or turbine blades?

Finally, and I ask this because it's not clear to me if your truck was serviced by your Nissan dealer, is there a remote chance that a turbo out of the 144hp 4x2 asian model found its way onto your truck? The turbo designation is also GT2056V, but this lower boost model is fitted with oil lines only, no coolant lines.

do not forget that the turbo control valve is prone to fail on the D40's.

Good call. There was a lot of trouble with the actuators on the 2010 Thai builds (ST).

If the second turbo was from an ST and not an STX, it could easily have been the actuator. Was there a regular thumping heard for some time before the failure?

I'm pretty sure a turbo on full boost having its vanes closed erratically is going to suffer from it.

its a spanish built st-x.
not sure what turbo it is besides its a garrett.
there has been no engine modifications, so stock as a rock.
i havent got any photo's of the blown turbo/s sorry.
update:
i am hitting 15psi real early in the rev range (before 2,000rpm), its an auto so i have to wait for speed to pick up before it changes gear.
i get to a hill, i am just watching my boost gauge to sit on 15psi and the speed and rpm fall, it would change back a gear, maybe 2 sometimes.
this thing EASILY goes way over 20 psi if i put the boot in, i recon nearly 30 psi (only done it once but to test how much)! so "tatty" if your saying can't go over 20psi i recon its the wrong turbo then. could maybe be a ecu either.
anyway been in contact with nissan australia and they want to look at it & diagnose a problem for me.
the last 2 turbo's have been fitted by a independent repairer so warranty probably not goin to cover, but you never know.
let everybody know how i go.
cheers again for your feedback.

The D40 starts spooling the turbo up quite early. Full boost is achieved around 1800-2000rpm, so having 15psi of boost there is no real surprise.

Boost should be peaking around 19psi, I don't recall ever seeing mine go over that.

I'm interested in how you are reading the boost pressure. If you're querying the ECU (via the OBD port) then you would definitely have a problem with the turbo.

If you've put a boost gauge in, it's possible that the turbo is okay but the boost pressure sensor in the intercooler is faulty giving the ECU the wrong information, so while the ECU thinks it's only boosting at 19psi, it's actually pushing a lot harder.

Faulty MAP sensor in other words.

hey guys, thought i'd report back for an update.
a mate of mine that works at nissan here in cairns checked it over front to back & inside-out not a thing wrong mechanically or computer wise.
turns out when i first bought the ute & when it had its first service, they have put the wrong oil in!
my mate told me they only put one type of oil in (5W30 ACEA C3 Low Ash Full Synthetic). he thinks if they havent put this oil in theres a chance the oil wasn't passing through the feed lines to the turbo correctly, turbo overheats, turbo fails.
is there truth to this?
cheers and look forward to replies.

As far as i know the only reason they use low ash is so the DPF can function correctly, they dont use it in the manual version, so i cant imagine that not using a low ash oil could of caused a failure

I think the oil feed lines could manage even Magnatec. The fully synthetic oil (which is good) is usually chosen because our cars ingest a small amount of engine oil through the blow-by and you don't want chunks of deposits blocking the CAT (or the DPF, which is why 2006-2009 D40 auto service costs are $45.50 higher than other models - for the ultra-low-ash JASO-FD oil used).

Let's say that I'm not convinced in that being a good reason for the turbo to fail.

The earlier description of turbo failures is (in my experience) the most common cause for failure, particularly one where the compressor strikes the housing and disintegrates.

No way your choice of oil has anything to do with the turbo failing. It's viscosity and general make up not critical for the turbo at all. I would recheck oil pressure and the pcv to make sure crankcase venting pressure isn't affecting oil pressure.

Hi guys my d40 was running low on power & blowing a lot of black smoke. As a Christmas present to myself I took in to a mechanic for a service & check up as I wanted to use the car a fair bit other the break & didn't have time to look into it myself. The mechanic called me on Christmas Eve before I was going to pick up the car to tell me that the variable veins in my turbo have seized up & a new turbo was $2600 plus installing. He won't be back to work until the 6th just seeing what other options are out there? Any advice much appreciated

You could try rebuilding it. Maybe send Forefront Industries a PM (they're a member here) and see if they do a billet replacement - you'll get better performance than the stock turbo.

Your mechanic is useless

From my experience when ever replacing a turbo also replace oil feed line.

These generally block up closest to the turbo as this is where it is the hottest.

Diesel turbos are on boost alot more and longer compared to petrol turbo engine.

When Turbo bearing cartridges fail, 90% is due to low or no oil feed.

This is very common now on the xr6 turbo falcons.

A turbo timer is the way to go.

I'd make your mechanic cover the cost of the replacement turbo and labour.
He should know better.