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Location:
Perth
Registered:
August 2002
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4agte turbo oil leak
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Sat, 08 October 2005 08:43
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I have had this problem for a while. Basically oil leaks from the bottom of the bearing casing beneath the two retaining bolts holding the bearing casing to the turbine housing. It seems to leak more when the engine revs (i.e. more oil pressure and oil). I have had the turbo reconed, reduced the oil restrictor to 0.8mm, 1/2" drain into top part of sump, and I have breather on rocker cover to atmnosphere.
The last thing I can think of is that the oil level in the sump is a tiny bit high. What do other people have there oil level set to? Any other ideas??
Any help is appreciated.
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Location:
Penrith
Registered:
February 2005
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Re: 4agte turbo oil leak
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Sat, 08 October 2005 12:24
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I have this exact same problem. I've just had my turbo rebuilt and now when I rev it it leaks and burns oil and it's barely drivable cause of the stink. I changed the oil feeding banjo bolt from 1.6mm to 1.3mm and it seemed to help but I don't want to restrict it any further in case I starve it of oil.
I have a warranty on it so I degreased the entire engine bay today just to make sure that it's not stray oil from somewhere else before I go to the hassle of taking it out again.
My oil was very low so I don't think that the oil level is the cause. My old turbo didn't do this but it wasn't ball bearing.
Any one got any ideas???????
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Sun, 09 October 2005 04:52
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Lowered oil level to 1/2 full, still no luck. I dont want to make 0.8mm smaller because of oil starvation. Would the oil viscosity be to thin?? What are you running with trubo and oil setup??
Any luck with warranty and what it could be??
Anyone else with ideas??
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Location:
Tas, Australia
Registered:
March 2003
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Location:
Penrith
Registered:
February 2005
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Re: 4agte turbo oil leak
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Sun, 09 October 2005 07:59
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I haven't had a chance to go for a run in my car since i degreased the engine yesterday (today being Bathurst 1000 = lotsa drinks).
Did this problem continue after your turbo was rebuilt??
Mine didn't do it when it was non BB but after a rebuild and a BB housing was installed instead of standard bearing housing it has been leaking and mainly when I back off the accelerator.
The guy who made my turbo said that he ran it up on a test rig while it wasn't installed to my car and he said that it ran fine. I have tried all oil levels but to no avail.
I'll let you know how it go's.
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Location:
Adelaide
Registered:
January 2004
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Re: 4agte turbo oil leak
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Sun, 09 October 2005 08:04
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Maybe you guys need a bigger or better designed drain to the sump? It sounds like your pumping heaps of oil in with nowhere for it to go.
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Sun, 09 October 2005 08:30
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I am restricting the oil with 0.8mm as I have BB turbo. then the drain is 18mm diameter inside and free of kinks. Have you guys been driving your cars as I am afraid the turbo will start a oil fire.
It doesnt seem to come out of exhaust, only a bit of carbon...
help...... 
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Location:
Tas, Australia
Registered:
March 2003
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Sun, 09 October 2005 09:43
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I may do a quick check of oil pressure after restrictor. What should BB turbo see for oil pressure at idle and running?? It is weird that it doesnt seem to leak when cold, maybe thicker oil means more restriction through hole. I do not think i can get any better oil drain than it is.
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Location:
Adelaide
Registered:
January 2004
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Re: 4agte turbo oil leak
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Mon, 10 October 2005 00:42
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| sebta22 wrote on Sun, 09 October 2005 19:13 |
I may do a quick check of oil pressure after restrictor. What should BB turbo see for oil pressure at idle and running?? It is weird that it doesnt seem to leak when cold, maybe thicker oil means more restriction through hole. I do not think i can get any better oil drain than it is.
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Yeah, thicker oil will not flow as well casue it's more viscous, perhaps you guys should try a thicker (more viscous) oil.
Actually, thinking about it then it would reduce the flow of the oil out the turbo as well, but since it will be getting heated in the turbo it could work.
Just ideas! Hope they help
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Registered:
May 2002
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Sat, 15 October 2005 05:53
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Any you guys had any luck??
I managed to measure the oil pressure between the restrictor and turbo and the it was sitting at 8psi during idle which slightly low. I may go back to larger hole and see what happens to pressure. Weird thing is that when I added the T piece and adapter for oil gauge the oil started leaking somewhere else. Anyone got any ideas?? I am trying any explaination.
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Location:
Penrith
Registered:
February 2005
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Re: 4agte turbo oil leak
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Tue, 18 October 2005 10:59
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Just got back from holidays and still havn't had a chance to take my car for a spin.
My oil return is the same as it was before when my turbo was non BB and it was handling a lot more oil back then.
I think you might be on the mark with the angle theory. Mine is fed from the top at about 5 degrees of center. Maybe BB turbos are just more susceptible to this problem than standard bearing.
I seem to be getting a lot more oil in my catch can now too.
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Sun, 23 October 2005 11:28
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JUst tried opening the restrictor 4-5mm and measure the oil pressure. Measured 30psi on idle and 50 psi and above when revving. It seemed that the oil leak between the turbine and bearing centre stopped but the extra pressure blew the gasket for the oil inlet, with oil dripping. I will need to fix the leak before any more testing.
Any ideas?? One of the cuff idea was that there was to much exhaust pressure which was over coming the oil pressure becuase when i was reving the engine the oil pressure wouldnt increase over 10psi, therefore I need larger restrictor. Maybe?!
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Tue, 25 October 2005 05:55
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I just talked to one of the guys at works old man who says that if the bearings are jounral (or plain bearings) that they require full engine pressure and oil flow to bath the bearings and keep them lubricated. This sounds like the problem for all of us. When I tested with full flow it didnt leak at the rear or blow smoke only leaked at inlet gasket  . Tell you what I find out when I fix gasket.
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Registered:
May 2002
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Re: 4agte turbo oil leak
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Tue, 25 October 2005 06:11
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| Quote: |
I just talked to one of the guys at works old man who says that if the bearings are jounral (or plain bearings) that they require full engine pressure and oil flow to bath the bearings and keep them lubricated. This sounds like the problem for all of us. When I tested with full flow it didnt leak at the rear or blow smoke only leaked at inlet gasket . Tell you what I find out when I fix gasket.
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Good to hear you appear to be making progress but I fail to see in that above comment how increasing the flow/pressure of oil entering the core you will fix a leak you have at the housing to core interface???
Sorry if I have misread or misunderstood something you are trying to explain.
What is this guys credentials that you got this advice from, it sounds like he is just describing the oil delivery required for a standard engine bearing i.e. big end, con rod, etc.
As I stated in my post earlier, I HAVE fixed the exact problem that you and most others appear to be having, my car has been a 4AGTE for nearly 5 years now and my turbo is 5 years old and still performs perfectly, pretty sure I have got it sorted  .
I will revise for those who missed it:
Ensure your engine has good crank case ventilation if this is not up to scratch the pressure created WILL force oil past turbo seals, housing to core interfaces etc.
Ensure your drain is of adequate size (>19mm) and is damn close to vertical ALL the way from turbo to sump and that it enters the sump at a steep angle, NOT horizontally. It also must enter the sump at the very highest point!
With the oil feed, most turbos have the restrictor integrated into the oil feed port on the core. If not, then simply chat to a reputable turbo outlet and ask what the restrictor size is meant to be for your particular turbo.
All pretty simple really.
If you follow the above I guarantee you the turbo on your 4AGTE will not have any issues.
[Updated on: Mon, 31 October 2005 00:37]
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Location:
Perth
Registered:
August 2002
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Re: 4agte turbo oil leak
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Tue, 25 October 2005 07:06
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The mates old man has been a mechanic on performance cars for twenty years or so.
I agree that using a restrictor is necessary on ball bearing turbos but on plain bearing turbos they require full oil to bath the bearing and provide an oil film to ride the bearing on. I think that full oil pressure will force the rear seal to seal properly with pressure applied from one side.
I have discounted all normal ideas such as crank pressure (breather mounted directly to rocker covers) and drain (new 1/2" drain as close to sump top as possible).
See what happens with full oil flow?
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Registered:
May 2002
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Re: 4agte turbo oil leak
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Wed, 26 October 2005 00:24
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I was stuck at work last night for a bit so I did some online research on the above problems and questions raised in this thread:
1. The interesting thing I found was that nearly all the information on the turbos leaking/burning oil related back to honda turbo conversions and 4AGTE setups. One can assume that a lot of people aren't getting their homegrown turbo setup right The rest related to worn out turbos.
2. All information I found indicated that turbos DO NOT function on full engine oil pressure regardless of if they are ball bearing or plain bearing. A maximum of 25psi oil pressure for the turbo was widely coined.
3. The general consensus was that ball bearing turbos generally use a restrictor of 0.8mm and plain bearing turbos use a 1.0mm restrictor. This is what my local turbo supplier also stated and recommended that I run a 1mm restrictor on my plain bearing turbo.
4. Oil drains appeared to be the most common problem amongst the DIY turbo setups.
| Quote: |
I agree that using a restrictor is necessary on ball bearing turbos but on plain bearing turbos they require full oil to bath the bearing and provide an oil film to ride the bearing on. I think that full oil pressure will force the rear seal to seal properly with pressure applied from one side.
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This is contrary to all the information I found with regards to plain bearing turbos. The statement you made about full oil pressure will seat the seals is flawed also as an increase in oil pressure in the turbo core is created by poor drainage and everyone knows this has devastating effects, thus how could an increase in oil pressure over the recommended pressure be good?
Have a look at a cut away of a turbo and have a think about how the oil passes through the core and how the seals work. You will see that the seals (rings) will suffer from increased friction and premature wear if they are exposed to excessive oil pressure.
If you want to check up on anything I wrote above do some research or flick an email to one of our local turbo suppliers
If the 4AGTE was able to have the oil drain flow into the block i.e. well above the oil level in the sump I think we would be seeing a lot less problems about 4AGTE turbo oil leaks/smoke 
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Location:
Canberra
Registered:
May 2002
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Re: 4agte turbo oil leak
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Wed, 26 October 2005 07:25
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I'll 2nd all of the above
Garrett actually publish the recommended oil flow RATES (in litres per minute) recommended for each of their bush bearing core designs. I have glanced over one of these reference manuals, and the approximate rates from memory were between 1.1 & 1.5 litres per minute, varied for the different Txx models & their relative oil galleries/bearing size.
The rear seal on the shaft of your turbine is no different to a piston ring, it should not function better with excessive oil pressure.
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