rx7_turbo2

I have a TD07 25G and have had a smoking problem. The car does not smoke on start up, it will only begin smoking once the car is up to temp and usually after a few boost runs. I had a problem with my old stock turbo blowing oil in the exhuast so I figured maybe it was just the old exhuast system coated in oil. Once I ruled that out I pulled the turbo and found the pictures I posted.

The manifold is dry (some oil spotting on runners, probably reversion) but mostly brown and dry. The exhuast housing however is very oily as you can see. Now I've had a high oil pressure problem on this car, but since I'm using the stock shitty FC gauge I could not tell you the exact pressure. I run a -3 oil feed line and a large drain. The drain does not however have a very large drop. If I was to use the "rise and run" description I would say the run is 6-8" and the rise is only 1.5-2" max. It's hard to get a hose to turn 90degrees in that short a distance. Now with the turbo off the car I plugged the oil drain and blew smoke into the oil feed. Smoke began to come out around the turbine shaft. I'm not sure if this is normal? I assume if air can pass by oil would have just an easy time.

I'm fairly confident the smoking problem is the turbo. So my questions are if the oil drain somehow gets blocked up because of improper drainage can this cause the high oil pressure problem. Or is it more likely I have a buggered oil pressure regulator? Anything else that could be causing the high oil pressure? And finally does this mean the turbo is hooped, or if I solve the high oil pressure will the turbo operate as normal?

Thanks for any help.

dubulup

do you have a restrictor in the oil feed?

rx7_turbo2

No. I wasnt sure if I should run a restrictor when I'm already running such a small feed line. What's your take?

dubulup

I'm not sure about mitsu turbos, but my garrett smoked with FD oil pressure. I bought the restrictor at www.atpturbo.com and it stopped.

I do know that a backed-up oil line will push oil passed seals like shown in those pics.

if you can blow smoke passed the seals, I'd think the oils seals are blown.

My oil return is -12AN line and similar to what you described...but a very nice round bend

dubulup

turbo's don't need too much pressure...

my feed is a -4

rx7_turbo2

Thanks.

My concern is that if I run a restrictor it's kind of a patch for the problem. I'm running higher that normal oil pressure, I think I need to get to the bottom of that, then I'll start addressing the oil supply/return issues. I really don't want to rebuld this turbo but if it's neccessary I guess.... That's something I forgot to mention, this is like the 3rd turbo I've gone through like this (2 hybrids, TD07). I'm not sure if I've just had bad luck with turbo rebuilds, or if there's something in my setup that's causing this.

supracosworth

Sorry not answering to your question, just to add that I've a similar problem with my TD06-25G which was fine until I let the car sit in the garage a couple of months and when I start her up again, she's smoking as you've described. When I have the engine running with the compressor side intercooler piping removed, I can see oil coming out from the compressor in a small stream. Pretty bad I'd say. There's no free play on the shaft axilally or radially but I sent it to turbochcargers.com anyway to have the seals changed. I got a response from them a couple of days back that they found absolutely no problem with the catridge so I'm now hoping that it's just a blocked return oil line. I assume the oil return line holds no pressure and I think I'll just replace the standard line with an AN6 braided line to see if that solves the problem. Wonder if anyone's ever experience an oil passage blockage past the return line and requires dissassembly of the engine to clean up?

Carl Byck

I use a .125 restrictor, the rear iron vent for my catch can, and a -10 return, 6" straight down, and 90* into the engine. No smoking. Previously, I had a return line sort of J shaped, and a -3 feed. The car smoked like crazy. In speaking to most Garrett distributors, their oil seals are good to about ~60-70 psi before they start to bypass oil on the hotside. if you have oil on the cold side you are really running too much oil into the turbo. ATP sell a .6, but IMHO that is too small. the .125 works for me, and I know several others using a .08 with good results. As for oil seals being "blown", this is not possible on a new piston ring, as it cannot be pushed from its land. whith wear, it could happen, but agin it is not likely. Call Mitsu, and see what there max recomended oil pressure is, then get a restrictor recomendation. Fcs, and FDs run too much oil pressure for most turbos. Proper venting is also very important. Carl

rx7_turbo2

Thanks Guy's

Any source for those restrictors?

I am waiting to get my oil pressure gauge. Then I'll know exactly what pressure I'm running.

rx7tt95

I had the same issue with a GReddy T78 (it's a Mitsu also, just a bigger compressor) and it was a seal issue. Since this was a stock GReddy kit, they (I'm assuming) didn't feel the turbo needed a restrictor. The problem with the Mitsu turbos is that they leak where they do on the turbine side and it'll eventually drip down through the housing to CHRA interface and onto your really hot manifold. What size oil feed line do you have and is it a stock GReddy or RE-A kit you're using?

For my latest setup, I purchased 25ft. of 5/8" aluminum tubing through JEGS. Was $25 or so. I then painstakingly bent it in place with only a rubber connection at the turbo and at the oil drain fixture going into the block. It'll never bubble up and cause a blockage and will never crimp either. Haven't had a single issue in the 4K miles I've had it like that using a Garrett GT series.

setzep

I have a TD07 also and also had your same problem when I put my car together a few years back. To fix it you'll have to run a restrictor, no question about it. Running a -3 line will do nothing to restrict the oil going to the turbo. I currently run a .081" restrictor right at the turbo but I've since upped my oil pressure and now it's starting to smoke again so I'll have to go with the .070" I have. These turbos don't need a lot of oil to survive.

jreynish

iTrader: (2)

My td07 is fine, I have a ..08" restrictor in my line and I have no problem at all infact I pulled the turbine housing yesterday to get a new V-Band FLange welded to it. And it was a nice coated Brown.
RX7 Turbo2, Did you have a restrictor in your hybrids? Or was it a stock center section? Because I had to restrict my hybrid also, It did the exact same thing!

rx7_turbo2

No I didnt run a restrictor in my hybrid's either. It's really a strange senario. I ran it for 2 days without any real smoke issues and then all of a sudden yesterday it started up again. Since I don't currently run a restrictor, and it seems most do, I will get one and put it in. I will also redo the oil drain in the turbo and see if that helps.

Anybody have any online sources for restrictors?

Old Slow Coach

restrictor source quoted here...

thanks for the heads up on this thread! I'm going to order a couple different sizes... I will start with the smallest, and work up until the problem is solved.

Carl Byck

I hope you mean largest a .125 is working so far on my PT67. Carl

Old Slow Coach

True, I should have thought "largest".

btw, I thought more about my situation and my current thinking is that my #@%* seals are going bad, and I ought to pull the turbo and have it rebuilt. I've observed oil seeping through the turbine to center cartridge retaining bolts/clips, after the car has sat a day or two. THis is a new development, which coincides with the smoking issue. THere aint no oil pressure forcing oil into the turbine when the car is shut off, so catastrophic seal failure seems imminent.

setzep

Try a restrictor before you spend the time and $ rebuilding the turbo. My turbo would leak oil out the turbine seal, between the housing and center section to drip on the exhaust manifold 7000 miles ago. I put a restrictor in it and no more leakage until recently when I upped the oil pressure. Now it's time to pop in a smaller restrictor.

black93RX7

Old thread...

Where would I buy a restirctor for a T78?

And would it screw directly into the turbo? or

would it connect to the -4an male fitting I currently have on the turbo?

The old setup I had would smoke like crazy under boost, just had my turbo rebuild and dont want anymore problems.

Thanks

Jon Goodwin

I have had the same problem on a new 13bre hybrid engine. Had the turbo rebuilt, and have changed oil viscosity when it stated smoking again. Have -4 in. will a .80 restrictor do?

John