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The turbo (the actual compressor housing?) or the turbo wastegate actuator? You've said it's gone to the actuator as well as it going to the turbo..

Sorry I do mean actuator when I say that. The red hose is connected to actuator, if you look closely in the picture you can almost see it.

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Possible that debris fell from somewhere and smashed the turbine. Perhaps the turbo was spun pretty hard then removed and sold to you, and you just got unlucky? Just change the turbo again. Get an R34 turbo if you can for a little upgrade ;):P.

Yeah I thought this too but it's happened 3 times, after everyone's opinions though I'll try a couple different things out when I'm changing over to the new (did you mean rb25 neo) turbo?

The line on the gauge you are talking about is halfway to full in positive pressure? If so from memory that seems about right

Perhaps there is to much heat in the exhaust side, maybe its running to rich?

Does it backfire, shoot flames or have poor fuel economy?

Edited by 89CAL

The line on the gauge you are talking about is halfway to full in positive pressure? If so from memory that seems about rightPerhaps there is to much heat in the exhaust side, maybe its running to rich?Does it backfire, shoot flames or have poor fuel economy?

Yeah man 3 quarters so inbetween positive 7 and half. Too much heat on the exhaust side does sound like a high possibility actually because I heard that those ceramic wheels don't handle too much heat very well... It does have pretty poor fuel economy, it back fires sometimes, I think it does run rich because when I bought it. It had an N/A manifold on it and the lines were blocked. But ecu and injectors were still turbo (the car is a factory gtst)

Did you use the same w/g actuator on all the turbos? could also be a boost leak too, if its leaking badly the w/g will not open when it should

The boost reading seems to be normal also and all turbos have had their own actuators!!

Point being if there is a boost leak, the waist gate actuator will keep closed and spin the turbo harder until it reaches normal boost level.

Ohh okay!! So a boost leak would just be from loose or split piping from any pipes on the turbo side??

Although it would be running awfully rich if it did, how has your fuel economy been?

Hmm well i get about 300kms to a tank give or take. Regardless of how the car is driven, and I've done and re done all of those pipes a few times now.. Is there a simple way to try and find a boost leak? Or shall I just change all the piping and all of the boots cause they're pretty old could be split or anything

First up, the point on the intercooler piping where the boost sense is taken from (red hose nipple) is on the wrong pipe. Sure, if nothing else is wrong, it will work there, but if you have one of a couple of other problems that position will make more trouble for the turbo. If, for example, you have a restrictive intercooler (or a rag in the intercooler as the classic line goes - but it does happen from time to time!) then you will be reading the boost pressure AFTER the restriction. So the turbo will be pumping to quite high pressure, but the engine and the wastegate only sees a lower pressure and everything seems normal - except you destroy ceramic wheels. Same sort of thing can happen with a boost leak although that will tend to be a problem regardless of where the tappnig is done.

And I would like to point out to people that it's not really heat that makes the turbines come apart or separate at the joint to the shaft. It's overspeed. If you're running retarded or otherwise hot in the exhaust side then the high temperatures will lead to high shaft speeds. So it is a little hard to say whether the chicken came before the egg or the other way around.

I would definitely do two things. I would fit another tapping point to the intercooler hot pipe and I would get a known good boost guage and hook it up to both of those tapping points (not at the same time, obviously) and see what the real boost is, and see if the dash gauge can be trusted.

Also, with respect to what boost the dash gauge is reading....+7 (hundred mm of Hg) is pretty close to 14 psi. Therefore the halfway line is 350 mmHg and is about 7 psi. If you are running halfway between those then you are up over 10 psi. That's high enough already - the car will likely be edging into R&R at that point. If the boost gauge can't be trusted, then your actual boost pressure is anyone's guess.

If the vacuum hose goes straight to actuator assuming the actuator is working then it shouldn't be boosting more then what it should. Its a simple analog pressure valve.

Those turbos re almost 20 years old with unknown conditions, not much of a point of buying them 2nd hand. Since you went through few its probably worth high flowing one of your dead turbos, you can then run what ever boost your engine and mods are happy with, for much better performance.

First up, the point on the intercooler piping where the boost sense is taken from (red hose nipple) is on the wrong pipe. Sure, if nothing else is wrong, it will work there, but if you have one of a couple of other problems that position will make more trouble for the turbo. If, for example, you have a restrictive intercooler (or a rag in the intercooler as the classic line goes - but it does happen from time to time!) then you will be reading the boost pressure AFTER the restriction. So the turbo will be pumping to quite high pressure, but the engine and the wastegate only sees a lower pressure and everything seems normal - except you destroy ceramic wheels. Same sort of thing can happen with a boost leak although that will tend to be a problem regardless of where the tappnig is done.

And I would like to point out to people that it's not really heat that makes the turbines come apart or separate at the joint to the shaft. It's overspeed. If you're running retarded or otherwise hot in the exhaust side then the high temperatures will lead to high shaft speeds. So it is a little hard to say whether the chicken came before the egg or the other way around.

I would definitely do two things. I would fit another tapping point to the intercooler hot pipe and I would get a known good boost guage and hook it up to both of those tapping points (not at the same time, obviously) and see what the real boost is, and see if the dash gauge can be trusted.

Also, with respect to what boost the dash gauge is reading....+7 (hundred mm of Hg) is pretty close to 14 psi. Therefore the halfway line is 350 mmHg and is about 7 psi. If you are running halfway between those then you are up over 10 psi. That's high enough already - the car will likely be edging into R&R at that point. If the boost gauge can't be trusted, then your actual boost pressure is anyone's guess.

Do you think oil starvation could be the problem???

If the vacuum hose goes straight to actuator assuming the actuator is working then it shouldn't be boosting more then what it should. Its a simple analog pressure valve.

Those turbos re almost 20 years old with unknown conditions, not much of a point of buying them 2nd hand. Since you went through few its probably worth high flowing one of your dead turbos, you can then run what ever boost your engine and mods are happy with, for much better performance.

Hi Stao.....read my post. There are ways it could happen. Anything that causes that signal to be lower (where it is sourced from) than the turbo's outlet pressure will permit it to work too hard.

Do you think oil starvation could be the problem???

Maybe....but what happens when you have that is that the turbo spins up and gets hot, then the bearings gall and sieze and the sudden shock would be what shakes the turbine loose. But I wouldn't expect the shaft to spin nicely afterwards, and it sounds like yours still have been.

Well, most of Skyline turbos that came in has no exhaust wheels. The way of how stock turbine shafts are made is by attaching a small section of the ceramic exhaust wheel into a steel shaft. Both elements has different expansion and retraction rates, and its always the section of attachment which breaks off at the ceramic end. The age and history of them probably don't help either, I won't be wasting money and time trailing 2nd hand turbos if its my car.

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