Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   I wondered why I was burning oil... (https://www.miataturbo.net/diy-turbo-discussion-14/i-wondered-why-i-burning-oil-6843/)

samnavy 01-20-2007 05:15 PM

I wondered why I was burning oil...
 
Well, after deciding not to drive the thing to Fredericksburg tomorrow, I started dismantling.

I've had a steady oil burn since install. I've also had a very small oil leak that I thought was from the oil drain flange. But it turns out that my leak and my oil burn are from the same thing.

I'm assuming that what I've got here is an overpressurized CHRA pushing oil under and past the main turbine seal under the turine plate.

I'm very glad it turned out to be something at the turbine. I thought it might be blowing past the rings or getting through the intake.
The IC piping is dry as well as the valve cover breather line into the intake. I took out all the spark plugs and they show classic signs of running stinky rich... pure black soot... but no sign of oil burn. The inside of the manifold is also dry but lotsa soot.

So, my original assumption turned out to be right. I'm starting by enlarging the oil drain barb at the pan. If that doesn't fix it, I'm going to buy the ATP .035 restrictor. If it still burns oil, I'm just gonna have to accept that if you buy 4 turbos to make one, things might just not fit tightly enough to get a good seal in the end. That might be my impetus to save for a GT2554r.

Braineack 01-20-2007 06:17 PM

looks like a bad rear turbine seal.

Mouglie 01-20-2007 07:29 PM

becareful with that, a friends car caught fire while driving because the turbo was leaking oil... now his car is no more...

m2cupcar 01-20-2007 07:50 PM

:werd: that's why my project car has an extinguisher in the trunk

Braineack 01-20-2007 07:58 PM

really. i guess i should stop driving home without my oil filler cap on. done it twice in two weeks on both my miata and altima. you'd think the overpowering smell of burning oil would make me pull off the highway....

samnavy 01-20-2007 10:36 PM

I just took the housings off and pulled the wheels off and the shaft out. What I found might be bad news. It's definitely got some shaft play. I'd say a bit more than minor. The bearings have freeplay that I know shouldn't be there. It looks like this CHRA must have been seriously abused in a previous life. I know I did the rebuild right and the initial assembly had ZERO shaft play upon install. I'm gonna put it back in there in the meantime but I'm definitely in the market for a new turbo now. I could just look for another used but running DSM T25... but if I could verify the compatibility of a GT2554r compressor with my DSM compressor housing, I'd buy the first one I found.

cjernigan 01-20-2007 10:42 PM

I wouldn't worry about finding compatibility. ATP sells a cast 90* elbow that you can weld onto any compressor housing for the same effect of the DSM setup.

I too have a frankencharger on my car and it is crap, its been rebuilt/balanced professionally twice and has failed both times. So i got an SR20 T25 and not my downpipe doesn't fit when i put the SR20 one in today. The DP hits the subframe and wont lift enough, i need another 1/4 inch for it to bolt up.

Darn turbos. It never ends. That's what I get for buying someone elses project though.

UofACATS 01-20-2007 10:48 PM

Man that sucks to hear. Is your first choice another dsm T25, or are you looking toward the GT2554r?

F20turbo 01-21-2007 02:45 PM

Look for a used Mazdaspeed protege turbo...it happens to be a GT2554R:)

miatamania 01-21-2007 04:48 PM


Originally Posted by AndyFloyd (Post 73591)
Look for a used Mazdaspeed protege turbo...it happens to be a GT2554R:)

shit...your kidding? Is it a real gt2554r or a shitty turbo like the MSM is? I MIGHT have a friend of mine that has his old turbo.

RicanmiataRacer 01-21-2007 05:04 PM

wow sam you seem to have some bad luck thus far, no worrys shit happens for a reason. things will get better.

miatamania 01-21-2007 05:25 PM

huh, found this on the miataprotege forums:

http://www.msprotege.com/forum/showp...3&postcount=36

"I should have clarified a little more. The turbo used on the MSP definitely
shares the same wheel combination as the off the shelf GT25R catalog item,
meaning both turbine wheel and compressor wheel combinations are the same
(same size and same trim). There are a couple subtle distinguishing elements
between the MSP turbo and the off the shelf GT25R that set them apart, but
not in term of performance (power). One, the MSP turbo has a slightly
different compressor housing to accomodating the specific intake/intercooler
plumbing requirements for that vehicle. The other thing is one of the
components (either turbine wheel, turbine housing, or other CHRA component)
is of a slightly different material than the standard GT25R and carries a
different (higher) temperature rating. This could have been something done
to meet the OEM specifications for the turbo application, I don't know reason
behind it.

Aside from that, we have provide replacement CHRA's for that turbo and the
CHRA is the same one used on the off-the-shelf GT25R."

-Coming from a Garrett person :)

rotaryjunky 01-21-2007 07:10 PM

samnavy, you really deserve better luck. I have learned a ton from your excellent right-ups. Someday, your experience should be consolidated and archived. Maybe when my kids get a little bigger and leave me alone!

samnavy 01-21-2007 10:15 PM

WOW, thanks guys (tear forms and is quickly wiped away).

I just tried to remove a couple of the broken studs from my turbine housing. I destroyed the threads in one hole and broke my easy-out off in another. So, I'm going to use this turbine housing to experiment on for wastegate porting and buy another one.
But I just looked a few places and a .49 a/r T2 exhaust housing is tough to come by.

That's the last time I mess around with those funky nuts with the oval ends. Those things have screwed me every time I've used them. Never again.

MM, let me know about that stock MSP turbo.

TheBandit 01-21-2007 10:36 PM

Hey man, I would try and put an inline restrictor in to solve this. Sounds like the typical too much psi blowing out the rear seal. If you want, I think I have a few in stock.
-Michael-

cjernigan 01-21-2007 10:45 PM

Tell me about your restrictors. I have -4 line with a -4 to 7/16" adapter. I like the simplicity how many fittings would i have to add to my system to put one of your restrictors in? My line as a 90* end on it.

TheBandit 01-22-2007 02:15 AM

The restrictor I use is a male -4AN to female -4AN straight fitting with a .062" orifice. I find it is a bit easier to use than the standard 1/8 NPT restrictors. Let me know if I can be of any assistance. Sam, sorry this comes across as threadjacking, if you don't like it feel free to delete this post.
-Michael-

miatamania 01-22-2007 01:37 PM

I sent my friend a PM, he is out of state, also checked on the protege forums, we'll see.


All times are GMT -4. The time now is 06:46 AM.


© 2024 MH Sub I, LLC dba Internet Brands