its a long situation, so for those who have the patience to read, thanks for bearing with me!

i think i have it down to a bad check valve, but i am not too sure. i've been reading up on this and trying to figure it out since yesterday, so here's a little background info on whats going on....

i just installed a new tranny, stall converter, new braided ss return oil line, new pcv, and deleted the over-the-axle charge pipe. i also just got HP tuners so i can scan the car and such. before, when the stock tranny was good, the sts ran great, no oil problems at all, but then it lost gears, so it was time for a new one.

anyways, so my mechanic puts in the new tranny, and other goodies, and during the test drives, the car was running great driving normally, still no oil issues. i then decided to get on it a little bit just to hear that turbo spool up again (its been 4 months since i've been able to drive her!) so i give it a couple 40-60% throttle pulls up to 4500, and the car was acting different, turbo seemed to not want to spool or make boost. upper rpms car would stumble and miss. the boost guage would never go past -10 vac, so i figured a leak somewhere.

meanwhile, while driving i have the HP tuners going, (1st time ever using the scanner) so i am just looking at everything not really knowing whats going on but i do notice that 1 of my Long term Fuel trim readings was out of whack, reading higher than the other one and occasionally flashing red, i'm thinkin, not good...

so we raise it up and find 2 exhaust leaks, fix those, but the car is almost out of gas, so i go for a test drive to the gas station. boost is back, so i'm thinking good, i can do a WOT run now.... well **** that didnt go to well. i floor it and the car absolutely runs like ****. my A/F jumps all over the place via my AEM wideband. i see on the HP tuners that there is KR, and the car is running really bad now.

i stop at a gas station to fill up, and notice oil coming out of the exhaust, like spraying with a small trickle dripping out of the tip... so i'm like well ****. i just take it home, as its the afternoon and i need to go to work, and let it sit in the garage.

later on, in the evening, i get home and take a look at it. the oil pump primes up turning the key, so i start it up. idling, oil is coming out of the exhaust in a light spray, along with a little trick dripping out of the pipe. i check the return at the oil cap, and oil is spitting out in spurts. you can see on the outside of the turbo, oil is dripping somehow on both the intake and exhaust sides. see pics




there is also oil up to my TB, so that means i have to clean all the intake pipes out and my maf is probably covered as well, which probably cause the LTFT on HP tuners to be out of whack.

the oil return at the cap was good on the first startup with the new tranny, before being driven at all. i am thinking that while running it with the exhaust leak, trying to make boost, it screwed up the check valve somehow?

we were thinking the seals on the turbo are bad, but after reading, these turbo's dont have seals...

then i thought maybe the oil pressure at the turbo was too much and i needed a restrictor, as i do have an aftermarket engine oil pump. but i have been talking with Billy at TRT and he said a restrictor would not be needed.

so any help?

 

Yes, the check valve is a known point of failure. Call STS, they will get you set. Replaced mine last year, had to clean out the system and clean off the MAF.

 

I would check a few things. I've had numerous prob with the oiling system on my STS car and it has always been one of these things:

First off, since you were working on the car, make certain that the return oil line from the turbo to the engine is not pinched or kinked anywhere. This could cause a backup in the return and would cause the oil to leak out the turbo (That one had me stumped for 2 days!)

Next, check to make sure that the drain coming out the bottom of the turbo is absolutely perfectly perpendicular to the ground. If it is clocked out of 90 deg at all you will have a problem from my experience.

Also, with the stock T60 turbo I didn't need a restrictor but with anything larger I did. I don't know why.

Those are my experiences.

Good luck!

 

Absolutely critical.

 

i will check the return line again, i know my mechanic had said he checked it... but i'll have a looksee at it. the main reason i replaced the return line with braided SS lines was to avoid a pinch or kink problem!! as for the return fitting, if you look at the top pic, it isnt a perfect 90*.... that could be a problem... what do you think?

 

That could certainly be a problem, it rotates and absolutely has to be 90 degrees. But the oil on your MAF is the check valve. I guarantee, went through it myself. I called STS, and they just said "What's your address, we'll send you one". No charge to me at all, except the labor I put into it.

 

make sure the electrical connections on the pump havent been switched. one side is positive the other negative if they are hooked up backwards pump pushes oil into turbo instead of pulling it out.

 

lol i have had the same thing happening to me for a while.... i wouldnt think that it was a check valve.... Im running a Garrett 60trim t3/t4 .63 a/r turbine and i had the same problems...... i have an extra check valve im gonna get another and run 2 in a row before the turbo.......

should i run a restrictor on my garrett 60trim?

 

well STS hasnt been picking up, so i might just go find a check valve somewhere local and try it out... anyone know who carries them? napa, auto zone, home depot?

is it possible to run 2 before the turbo? i know the valve opens under pressure, so i guess having 2 would be like having one as a backup?

 

you really only need one check valve and an oil restricter (function7 on ebay sells them). Here is the part # for the check valve from mcmaster carr

7768K51
Brass Spring-Loaded Piston Check Valve 1/8" NPT Female X 1/8" NPT Female, Viton Seat

and the inlet restricter
http://cgi.ebay.com/ebaymotors/Funct...QQcmdZViewItem
theres a thread somewhere that shows how much to drill it out.

hope that helps. Goodluck

edit: I found that thread with the restrictor size info
https://ls1tech.com/forums/forced-induction/569238-oil-line-restrictor-poll-guys-chime.html

 

Lingenfelter sells a nice check valve. I got one for my set up. They sell them on eBay.

 

well i finally fixed the damn problem. i checked EVERYTHING, and i mean everything: electrical, return line, check valve, etc... but i still had oil spurting out everywhere and filled up my garage with about 2-3 quarts... in the end it ended up being the check valve. i replaced it TWICE, as the first new check valve i switched with the old one got stuck open somehow.. the second one cured the problem altogether.

i guess since the car had been sitting while i made time to work on it, the oil had just been pooling up inside the turbo. it was a bitch to clean all the charge piping, and i'm sure the intercooler was full as well.

oh well, its fixed, now its time to go have some fun with my new tranny.

 

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