Had a thought about turbo failure that I think may be interesting to discuss, we all have read the painful tales of woe here when your favourite toy starts smoking and the dreaded turbo failure hits you in the pocket.

 

Having been around scene since it started I have read hundreds of such failures and yes in the early days they were mostly standard turbo`s on cars approaching say 100k miles and many having been subject to sketchy or careless servicing by previous owner`s.

 

As the scene has taken its lead from the US many, many big build engines or just turbo changes have now been less likely to be rebuilt standard units but upgrades or hybrids from the US and such like.

 

However the turbo failures seem to still occur, but the difference I see is if and when they do its never on 100k miles but way less some under 5k miles, also I read of standard rebuild units failing with low miles on too.

 

So I guess what I am thinking is why do the original units even when badly serviced last so long when very expensive hybrids seem to have a failure rate of their own with way less miles on, and equally rebuilt units can fail it kind of begs the question is it better to buy new units from Nissan if available? even if the cost is way more expensive in the first instance, rebuilds simply do not seem to last so long and of course doing the job twice is always more expensive.

 

Of course there is many variables that can effect the life of the turbo`s and as the original factory ones were fitted to a brand new engine that could be the key, but high quality engine rebuilds still can suffer from the dreaded turbo failure which seems madness.

 

 

Of course there may be some who have rebuilt or big turbo`s here with no problem, but most zeds here do not do big miles any more so it can be difficult to be sure, has anyone done 100k on hybrids with no problems?

 

Thoughts ??

 

Jeff

My stock (original) turbos are still doing very nicely. They've been great and I've been running about 1 bar for nearly 6 years now.

 

My stock (original and unmodified) turbos are also still doing very nicely and have been running 1 bar max for over 16 years.

I have a pair of nearly new JWT 530BBs on standby.

My stock (original and unmodified) turbos are also still doing very nicely and have been running 1 bar max for over 16 years.

I have a pair of nearly new JWT 530BBs on standby.

 

I'd quite like to get a touch more out of them. I'm looking at 555s currently and want to push to 17PSi once mapped. They're a good turbo, responsive and can take quite a beating.

I didn't say it was.

 

So what was the point your trying to make then ? about your Surfs original turbo and other cars with oil in the intake system ?

Am I right in taking that Chrisbasildon was saying that the failed turbo's he sees at work have oil and muck in the intake from oil ingress from breather systems, etc. that then goes through the turbo?

Would this muck being sucked through it, shorten the life of a turbo?

All the turbo's I have had have lasted due to fresh clean Castrol RS oil and filters, replaced feed and return hoses and also allowing them to cool down slowly with a bit of idling before turning off the engine.

My old series 1 RS engine used to have a glowing turbo after a good thrashing and I would go for a slow poodle around for a few miles before heading home just to allow it to cool down to normal running temperature.

I was always told that the oil and water are there to cool and lubricate the turbo, so suddenly taking away lubrication and cooling from a very hot turbo causes it to heat what water and oil is left.

So I have followed the advice I was given years ago...... whether right or wrong.....

 

Was I right in thinking different metals cool at different speeds, so internals on turbo's, such as impellers, seals, snail shell, etc will contract and expand independently causing clearance differences if one cools quicker than another?

Could different quality materials used, such as different metals with different mixes of materials cause problems?

Cheap alloys, steel, etc....?

Edited September 9, 20169 yr by veilside01702

Am I right in taking that Chrisbasildon was saying that the failed turbo's he sees at work have oil and muck in the intake from oil ingress from breather systems, etc. that then goes through the turbo?

Would this muck being sucked through it, shorten the life of a turbo?

All the turbo's I have had have lasted due to fresh clean Castrol RS oil and filters, replaced feed and return hoses and also allowing them to cool down slowly with a bit of idling before turning off the engine.

My old series 1 RS engine used to have a glowing turbo after a good thrashing and I would go for a slow poodle around for a few miles before heading home just to allow it to cool down to normal running temperature.

I was always told that the oil and water are there to cool and lubricate the turbo, so suddenly taking away lubrication and cooling from a very hot turbo causes it to heat what water and oil is left.

So I have followed the advice I was given years ago...... whether right or wrong.....

My car doesn't smoke or drink oil, but after long journeys there is some residue of oil in the intakes.

Note this doesn't mean the turbo steals are blown.

Edited September 10, 20169 yr by Alic

No he means oil from the turbo. My car doesn't smoke or drink oil, but after long journeys there is some residue of oil in the intakes.

Note this doesn't mean the turbo steals are blown.

So how did the oil get in the intake?

And won't that be sucked through the impellers coating them with old oil and residue?

Turbo seals blown would dump oil into exhaust....

Surely intake would mean a breather system leak?

So how did the oil get in the intake?

And won't that be sucked through the impellers coating them with old oil and residue?

Turbo seals blown would dump oil into exhaust....

I'm not the mechanic! I would just guess that on the impeller side some oil seeps out in the shaft and is sucked into the intakes as that's the direction the air is flowing.

More than likely it's ingested into the engine from the breather system. The stock design is ok, but it's major flaw is the cam cover vent location as these are too low and only on one head. Oil can poolin the head and be sucked up by the breather. In the turbos front seal is failing you will see oil residue heavily in the intercooler loop, and in worse cases when you boot it the pool that builds up in the intercooler language will be sucked up and burnt resulting in blue smoke on acceleration.

The most common failure in stock turbos is oil out the rear seal, presenting itself as grey smoke that is noticeable particularly on a warm engine at idle, due to the reduced rotation of the shaft and on deceleration. The rear seal on stock tubs isn't the best, the larger and later t28 is although the same core better in this respect.

From what I've read the failure of stock turbos or smoking is often down to poor oil changes and bad driving habits of both the turbo/engine and the breather system. Whilst the oil drain is quite big the galleries to it are quite small and coke up easy. The turbo core, esp being a journel bearing overfills with oil quite easily and presto smoke.

I remember when the

Norwegian government changed the taxing of cars some 10 years ago making diesel cars much cheaper than petrol. Everybody bought diesel cars and drove them(still do) like their earlier petrol n/a cars and everybody was having turbo failures on practically new cars, no wonder i thought. Never getting hot enough on small town errands, and being shut down without cooling off...

 

 

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So how did the oil get in the intake?

And won't that be sucked through the impellers coating them with old oil and residue?

Turbo seals blown would dump oil into exhaust....

Surely intake would mean a breather system leak?

 

correct fella,any boost leak will upset the balance of the breather system and pull oil through the intake.

So what was the point your trying to make then ? about your Surfs original turbo and other cars with oil in the intake system ?

 

The point I was making was the fact that my surf which is still running the original turbo at nearly 200000km is still going strong which is inline with the topic of jeffs thread is it not?

 

And oil in an intake system is not necessarily due to the turbo, I never said it was, I said every modern turbo engine I work on has a huge amount of oil within the intake system, whether this is the turbo at fault obviously depends on that particular vehicle but the turbo cannot be ruled out as the cause, and I KNOW that many times it is.

 

I've had turbo low and high pressure pipes removed and had oil running from the high pressure outlet on idle many times, take the garrett turbo fitted to the dv6 engine for example, I've replaced more of these than I care to remember, garrett point the finger of blame at PSA who build the engine.

I'm the first to admit that I don't know a great deal about turbos, so I'm far from qualified to comment on this topic with any real conviction.

 

That said, I've just come across a post from 2010 that may have a bearing on Jeff's discussion:

 

Link.

 

The salient point is, I believe, the part I've quoted below:

 

All of the above are analysed and among other things all the pressures across the device are analysed. This allows the overall thrust on the turbo shaft to be calculated which will determine the design and life of the turbocharger thrust bearing. This is why the aftermarket does hybrids (big comps on small turbines while the OEMs do not, at least in volume production at any rate) as the imbalance in the sizes of both items causes excessive thrust bearing loads.

 

As I said, my knowledge regarding turbos is limited at best, but I thought this was worth mentioning here as it seems pertinent to the discussion about why OEM turbos seem to last so long and aftermarket ones don't...

 

:thumbup1:

I'm the first to admit that I don't know a great deal about turbos, so I'm far from qualified to comment on this topic with any real conviction.

 

That said, I've just come across a post from 2010 that may have a bearing on Jeff's discussion:

 

Link.

 

The salient point is, I believe, the part I've quoted below:

 

 

 

As I said, my knowledge regarding turbos is limited at best, but I thought this was worth mentioning here as it seems pertinent to the discussion about why OEM turbos seem to last so long and aftermarket ones don't...

 

:thumbup1:

 

Thing is though and what seems to be being missed and is so very vital in that case. What turbos are we using that aren't OEM specs? Most, say 80% of the turbo kits for sale by the likes of Z1 are simply stock turbos from different models reapplied. The only ones that are used often is the gt525, which is a t28 core in t25 housing. Gt535 kit uses a gt2554 and gt600 thats a pair of gt2860. You can and I assume they do buy these straight off the shelf from Garret (owned by Honeywell btw). Stock turbos on a z32 btw are actually hybrids.

If turbos fitted to the Z aren't lasting as long as the factory originals, then there's only two options. Either Garret have dropped the ball and aren't making turbos as well or they are being fitted incorrectly. There is no reason if it fitted correctly your gt600 kit shouldn't last as long as the turbo the an S15 left the factory with. I spose abuse is also a factor but that's also a factor with stock, arguably more as people push them further than what they were designed for to eeek out extra ponies. Rather than running a bigger turbo softer.

Edited September 12, 20169 yr by Stephen

Thing is though and what seems to be being missed and is so very vital in that case. What turbos are we using that aren't OEM specs? Most, say 80% of the turbo kits for sale by the likes of Z1 are simply stock turbos from different models reapplied. The only ones that are used often is the gt525, which is a t28 core in t25 housing. Gt535 kit uses a gt2554 and gt600 thats a pair of gt2860. You can and I assume they do buy these straight off the shelf from Garret (owned by Honeywell btw). Stock turbos on a z32 btw are actually hybrids.

If turbos fitted to the Z aren't lasting as long as the factory originals, then there's only two options. Either Garret have dropped the ball and aren't making turbos as well or they are being fitted incorrectly. There is no reason if it fitted correctly your gt600 kit shouldn't last as long as the turbo the an S15 left the factory with. I spose abuse is also a factor but that's also a factor with stock, arguably more as people push them further than what they were designed for to eeek out extra ponies. Rather than running a bigger turbo softer.

 

 

i think just about 90% of things made today cars bikes houses tools t.v laptops ect just about everything are not made to last we live in a throw away time when its broke bin in sad really isnt it but thats the way the world has worked out people want cheap and that had made a new world of cheap crap just about every were you go

Certainly seems that way doesn't it. Built in insolence they call it, the alarmist would say if it's got a chip in it, it's got a date when when its programmed to fail. How many mobile phones last more than 2-3 years, enough to be out of contract...

the one i have is number 3 all have broke. stuff is just made to throw away thats the world we live in now it sucks

While we are on the subject of reliability, has anyone on here rebuilt a t25 with t28 compressor wheel and it working for a while?

I was thinking if you've got a blown turbo, it would be a halfway house of buying new t28s or rebuilding the t25s

 

(Though of course new t28s would be a lot more reliable)

Edited September 12, 20169 yr by Alic

Yeah loads of people, that's what z1 call the gt525 kit. The T28 is a better core and rebuild costs are the same as they use the same kit. Don't forget the cost to machine the housings would be additional.

When my turbos fail, and they will one day seeing as they are 24 years old, I will most likely just replace them with original turbos, they work fine and can handle a bar all day long, perfect for me.

Just had the stock t25s refurbed with t28 compressors and thought the seals had gone pretty much straight away (3k miles) but we haven't found any oil in the plenums so hoping its stem seals. Haven't had her remapped yet so so far £800 for refurb and balancing probably another £400 for remap(?).

 

 

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Just had the stock t25s refurbed with t28 compressors and thought the seals had gone pretty much straight away (3k miles) but we haven't found any oil in the plenums so hoping its stem seals. Haven't had her remapped yet so so far £800 for refurb and balancing probably another £400 for remap(?).

 

 

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Hook up a vac gauge to your oil dip stick tube and see how much back pressure there is or isn't. If the rear seal had failed you wouldn't get any oil in the system, just grey smoke from oil evaporating. If it's blue it's being combusted.

Definitely blue smoke that's why I'm thinking valve stems. Just found out we've got a boost leak so much to do now!!!

 

 

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