At the begining i bought the Dezod kit with a innovative Stage 5 turbo, it only lasted me maybe 5months with mostly beating on it by street & dyno tuning. The turbo had bad seals, it was sent out to innovative for repair, based on innovative i was told the seals went bad along with burnt oil inside the turbo (as if i never changed my oil, *yeah right!*) Anyways i decided to have it fully repaired. (a mechanic friend of mines thought we should unplugg the hose that connects to the intake pipe and close it up with piece of cloth so it wont spit oil inside the engine bay. since that could be the problem why im sucking oil inside the turbo)

In the mean time i went out and bought me a GT3076R, this turbo only lasted me maybe 3weeks, the seals went bad (white smoke like this: http://www.youtube.com/watch?v=PC-C64zZ6x4) , so we sent out this turbo to get it repaired, when it came back we installed it and the same thing happened, this time we decided to plug the hose back into the intake pipe. It worked ! for only 2months, and then just yesterday it all started happening again. I looked under my hood yesterday and i saw oil around the edge of the hose that connects to the turbo & intercooler pipe. (not the intake pipe)

-I take good care of my car and i dont beat on it everyday
-I change my oil every 2,500miles fully synthetic
-I use 93 Octane
-I always use my turbo timer (1min)
-Oil pressure reading 40-60 at WOT even when driving normally
-The GT3076R has a oil restrictor & water cooling kit
-AFR at WOT between 10-11.9
-VAC reading correctly at 20
-Currently boosting 11PSI (No Spikes)

What could be the cause of this ?

Any help would be appreciated.

 

so everytime its the same problem with the seals of the turbo being washed out due to hight oil pressure from the tC going to the turbo and blowing past the apex seals? If thats what im reading then do you have any sort of oil pressure restrictor going to the turbo? If you have 60 psi of oil pressure going to the feed line of the turbo your gonna kill the seals on every single turbo you put on there...put an actual restrictor on the line and have a t fitting coming from the restrictor and put a crappy gauge on there...limit the oil pressure to about 15-20 psi going to the turbo

 

correct, i do have an oil restrictor on the turbo.
I dont know if 40-60 is high oil pressure on tC's.

 

I've always been told not to use synthetic with a turbo.... something about it not being good for the seals.

 

say what?

 

seems like ball bearing turbos blow their seals more easily than non-bb? idk, i still have my s1 non-bb turbo and i got my kit a little before you. about 15k on the turbo i think.

 

yeah, I don't know if there is truth to it, but I've heard it from a few people.

 

actually, i remember reading a tech article that was posted on her by a link a while ago. it was about breaking in a new turbo, and one of the important things it mentioned was that you should use natural oil to break it in. so maybe it is better at conditioning the seals.

 

hmmm, i thought the pressure under full load was about 80 psi on a tC. You hafta find out how much of that oil psi is going to the turbo...like I said, anything over 15-20 psi will blow turbos all day long

 

I will talk with my mechanic on what you posted.

In the mean time if anybody else can chime in, it would be appreciated.

 

Simply is right. The tC's high pressure is causing seals to blow after a period of use. BB's are probably eaiser to blow than non BB's. Took me over a year and half and racing pretty much every weekend before my seals went on the 16G.

Anyone have links to some restrictors?

 

The biggest problems we've seen with turbo oil seal failure on turbocharged cars, that were originally normally aspirated, is usulllay due to the way the oil return line is setup.

Oil return line ID:
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The oil return line ID bore should be at least 5/8" or larger on journal bearing turbo and 1/2" or larger for BB turbo.

Oil return line routing:
----------------------
The most common mistakes we've seen with some aftermarket turbo kits is the way the oil return line is returned into the oil pan. The oil returning from the turbo into the oil pan is gravity feed, so if the oil return line dips down below the entry point into the oil pan, the oil can back up in the dip, causing the oil to find the route of less resistance, which is through the oil seals.

Oil return fitting on oil pan:
---------------------------
The tap for the oil return line on the oil pan should be located as high up the oil pan as possible. Ideally, the oil returning from the turbo should be dripping into the top of the oil fill line in the pan and not below the oil fill line. Imaging pouring water into a straw into a cup of water. If the bottom of the straw is above the water line, the water in the straw will pour out as quickly as you can fill it up. Now imaging what happens when you submerge the bottom of the straw into the water and then try to pour water into the straw, notice the water is still drain out of the straw but not as fast. This is what happens when oil is filling up the oil return line faster than it can drain into the oil pan. The farther down the oil is return below the oil fill line in the pan, the slower the oil can drain into the pan. When the oil can't drain fast enough into the oil pan, it backs up the oil line and finds another way out and that's usually through the oil seals on the turbo.

Oil line restrictor:
------------------
The ball bearing turbos, ie. garrett GT turboes does not require a lot of oil to lubricate the bearings, if you're converting from journal bearing to a BB turbo and forget to install an oil restrictor in the oil feed line, you will force oil through the oil seal.

Boosted Crank case:
---------------------
This doesn't really applied to the 2AZ-FE motor, but we've seen this happen on a 2ZZ-GE (celicat gts motor). The 2ZZ-GE motor has a crankcase breather hose connected right after the throttle body is perfectly fine for a NA motor, since that hose will always see vacuum or 0 boost. But when you put on a turbo, under boost, the boosted air goes through the TB, into the crankcase beather hose and then into the crank. What happens now is that your crank case is becoming pressurized and the pressure forces the oil in the oil pan back up the oil return line and into the turbo. Since oil is forced in from both direction (the oil feed and return return) the only way out is through the oil seal.


With that said, if you're blowing white smoke through your tail pipe and you've gone through several turbos in a short period of time, and your leak down test reading is good, then you have probably blown and oil seal. The first thing i would check since you're having the problem with both a journal and BB turbo is the oil return line setup.

BTW, 60psi of oil pressure is nothing, as long as you have adequately sized oil return line setup and also a restrictor (if using a BB turbo).

Good luck,
MrC

 

Ptuning-Your last sentence saying that 60 psi is nothing...as far as what? Running through the block you mean? Cause 60 psi thru a turbo means disaster obviously for the seals. I agree with you also about the oil return line...a lot of people overlook something as simple as that. When I ran a restrictor on my xB I actually had a brass restrictor T'd off to a pressure gauge so I was able to dial in the oil psi going into the turbo
edit: I should mention that it was an adjustable restrictor with a valve switch to open and close incrementally...which was the whole point of the gauge to regulate how much pressure was flowing to the turbo

 

I think you missed the rest of the sentence:

 

Again, if you have adequate oil feed and return setup, 60psi is not a concern. Just to let you know, the honda s2000 is already makeing 60psi of oil pressure at 2500rpm. At vtec the oil pressure is well over 60psi. Our turbo s2000 is running a gt turbo with just a oil feed-line restrictor even when the oil pressure is way north of 60psi when vtec hits. What we're trying to control here is flow not pressure. You can control flow by using a restrictor to reduce the flow or you can control the flow by reducing the oil pressure going into the turbo. So the simplest way to control oil flow to the turbo is using a simple and inexpensive restrictor instead of an elaborate oil pressure regulator. I don't know of any turbo kits or turbo charged cars on the market using an adjustable oil pressure regulator to limit the oil pressure to the turbo, it's not needed.

Not to get off topic, but let me elaborate on flow:

Let's take a fuel injector as an example in regards to flow. Why do people run larger injectors, to get more fuel to the motor. What they're trying to achieve is more flow (volume) of fuel within a given period of time (duration). You can increase the flow of fuel to the engine in a few ways: run larger injectors (the injectors will have larger orifice, so it can supply more fuel given the same duty cycle), run the same injector but increase the pulse width (how long the injector stays open), run the same injector and increase the fuel pressure via a fuel pressure regulator, a larger pump, or increase the pulse width on the factory pump (for returnless system). Of course the duty cycle (how long the pulse width is over a given duration dictates how much fuel a gven injector can flow. A smaller injector at 50% duty cycle is not going to flow as much fuel (cc/min) as a larger injector at the same duty cycle.

If you're injectors is at 85% duty (the max safety margin), it's time to increase your injector size. If you're running at 100% injector duty cycle, that means that your injectors are open 100% percent of the time. The solenoid that opens the injectors will overheat since it has to contantly maintain the opening of the orifice.

This brings us to another point about flow (volume). Given the same engine, a 16G turbo at 10psi is not not going to flow the same amount of cfm as a 20G turbo at the same psi. The same goes for the exhaust system. If you have the same engine and same turbo running with the same boost, if you're running a 2" exhaust system, at 10psi, the amount of air flowing in/out the engine is not going to be the same as a 3" exhaust system running at the same boost.

Sorry for the long reply,
MrC

 

That's all good and very informative. Problem is, my oil return line is a Direct Shot toward my oil pan (no, dip, bend, loop) period. And yet the seals Still blow.

 

Where did you tap the oil return line fitting on the oil pan? It it right at the top of the pan or an inch or two below the top of the oil pan gasket flange?

 

This is definetly some good info, thanks alot, i will run this by my mechanic.

 

watching..

 

No, I know, Im not talking about oil pressure through the block...i was talking about oil pressure going to the turbo...you brought up the S2000 running over 60 psi before vtec, hell, the 1nz block runs north of 80 psi under full load. I wasn't using a fancy oil pressure regulator to limit oil psi to the turbo, I was using a $5 brass fitting with a multi stage open/close valve...sort of like whats on the end of a garden hose to turn the water on or off. It was installed in between the line and oil sandwhich plate adapter with the T running a $10 crappy oil pressure gauge.