FP/ MHI Oil Drain Outlet

[4G63510]

I recently installed a FP 68HTA v3 turbo to replace my Garrett hybrid unit. I reused the oil drain outlet fitting as it seemed to fit exactly the same. Of course I used a new gasket, but I've developed quite the oil leak from this area. The bolt spacing seems the same and the -10AN drain line and fitting worked on the last turbo. Due to how tight it is, you have to use allen head bolts, so maybe it's not tight enough or I just don't know what I'm doing. It's a pretty massive leak, so I'm wondering if the outlet is different. I compared the outlet sizes before installing it, and everything seemed to be fine.
My only other thought is that I have backpressure in the line since the oil pan fitting leaks oil when I remove the line when it's parked. I have replaced the DSM oil pan with a RWD unit. I didn't think the oil fitting would be below the oil level, but it seems it is. I was hoping the oil level would drop enough during running that it wouldn't be an issue. The pan seems to hold the same amount of oil. I'm kind of at a loss. It seems like an easy fix, but I haven't had any luck.

 

[1990TSIAWDTALON]

@MorrisonFab has a selection of turbo drains that might tell you what you need or at least give info on the difference if there is any.

 

[Stapl3]

Teflon seal the threads on the bolts.

 

[talon749]

The T3 drain flange (assuming from profile that’s what you had) is pretty darn close to the Mitsubishi CHRA bolt spacing but off just a bit, the bolt holes are just a bit larger, meaning the Garret would “bolt up” just fine to a Mitsubishi housing but have enough gap to leak. Hoping Justin will comment on that. I can’t speak to the oil pan side, but I might question the actual oil quantity in the pan, dumb question but is the dipstick correct for the application? I’ll also add slick Datsun! Bet that’s a riot to drive.

 

[4G63510]

The T3 drain flange (assuming from profile that’s what you had) is pretty darn close to the Mitsubishi CHRA bolt spacing but off just a bit, the bolt holes are just a bit larger, meaning the Garret would “bolt up” just fine to a Mitsubishi housing but have enough gap to leak. Hoping Justin will comment on that. I can’t speak to the oil pan side, but I might question the actual oil quantity in the pan, dumb question but is the dipstick correct for the application? I’ll also add slick Datsun! Bet that’s a riot to drive.

My previous turbo was a Garrett hybrid. It had a Mitsu turbine housing, ball bearing CHRA, and Garrett wheels. The best info I can find is that it was a GT2971R and was sold by Slowboy Racing as a GT11. I did find this info on ExtremePSI that shows the return hole and bolt spacing should be the same. The only difference is the bolt holes themselves. Assuming of course my parts were the same.
I have questioned the oil capacity and how the pan works. I added about the same amount of oil I normally do with the DSM pan and the dipstick shows the "proper" level. I'm checking with a RWD group to see if anyone has better info. My other thought is just that I didn't have this issue because the ball bearing turbo has a flow restrictor and less fluid was traveling down the drain. Perhaps even my oil pressure is too high for this turbo since I'm feeding off the OFH, but many people have done this and it hasn't been an issue.
I will be following Stapl3's advice on sealing the bolts. I know the oil pan has rubber ringed washers for this reason, so perhaps the turbo needs the same. Now I need a new gasket :/

 

[curt-s]

I was talking to FP about the plumbing off the OFH for the 68HTAv3 with -4AN unrestricted feed and -10 drain given my oil pressure (90-100 is not uncommon cold, I'll top 80-90 hot with 10w30) and their response was to just run it like that.

I wonder if there may be a slight dip in the drain flange causing uneven pressure. I've always added a skim of RTV on both sides on both the CHRA and pan ends just for good measure. The only place it would leak after that is those damn pan bolt holes.

 

[4G63510]

I've elimnated those pan bolts by welding a -4 fitting on. Those have been trouble in the past.

I tried adding RTV after I initially found the leak, but it actually seems worse now. I'll try again and add sealant the the bolts as suggested.

 

[1990TSIAWDTALON]

These are the correct drain parts, if anyone needs them.

Mitsubishi OEM Oil Return Line to Oil Pan Bolt & Gasket Kit for 4G63 DSM/Evo

Genuine OEM Mitsubishi parts to replace the turbo oil return line gasket to the oil pan. Works with all 4G63 1G/2G DSM, GVR4 and Evo 1-9.

stmtuned.com

 

[4G63510]

I don't think I can use the bolts in the STM kit, but I ordered it anyway. Shipping is more than the parts, but I love STM and they always have fast shipping and great customer support.

 

[curt-s]

I've elimnated those pan bolts by welding a -4 fitting on. Those have been trouble in the past.

I tried adding RTV after I initially found the leak, but it actually seems worse now. I'll try again and add sealant the the bolts as suggested.

If the only bolts that remain are the ones in the CHRA side, those holes aren't through-holes. They're just drilled and tapped into the casting, so no oil could be coming from them unless there's some sort of crack.

 

[4G63510]

I decided to just pull the whole motor today. I had some low oil pressure issues I wanted to investigate. My leads didn't pan out, but I did find the source of my oil leak.

I thought it might be due to my drain line. It's not the best routing, but I need to snake around the motor mount a bit. That wasn't the issue, but I will tidy it up when I reinstall the engine.

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After pulling the return line, I discovered the real issue. It was actually two fold.

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Obviously I don't know how to install a gasket. Also, the bolts I was using are too long. They were fine on the Garrett turbo, but are too long and bottom out before tightening down on the drain adapter. Obviously I will be fixing both of those things. Dumb mistakes happen to us all.

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On a related/unrelated note (I don't want to start a new thread for this), which oil port should I be using on the EVO3 OFH? One of these is tapped for the turbo feed, the other is my oil pressure sensor. I'm getting odd oil pressure readings and I'm trying to decide where the issue is. I've gone as far as removing the front case thinking my BS delete was causing the gears to wear into the housing. It doesn't seem to be the issue, but it's bad enough I'm replacing the whole thing. I'm also going back to balance shafts after reading an article by Jack's Transmissions. Any thoughts on either of these topics is welcome. I can start a new thread, but I know there is a lot of info on the forums already. Except for the EVO3 OFH