secretsquirrel

Teflon tape somewhere (I mean ANYWHERE) in your oil plumbing? Maybe at the oil feed take-off from the block/pressure sender? A fly-spec of that crap will kill turbo bearings. - Just a guess, GL...

gianic

iTrader: (6)

So where the heck is the oil going? I can't see any smoke from the exhaust and definetaly nothing is flowing from the return line. Not a signle drop!

The oil feed flows ideally with the restrictor. I test it over and over.

same oil, same drain, a little larger restrictor.

The restrictor is fine. you can see through clearly.

gianic

iTrader: (6)

No teflon tape for me here.

gianic

iTrader: (6)

The line you see looped is the water line.
The oil return is straight down. If you draw an imagenery line from there it would make a perfect 90 degrees angle with the ground.

ARTech

iTrader: (34)

Ok, I see it now. If that's the case then yeah, there's blockage somewhere. Coked oil will clog up the passages but I don't see it happening in a matter of weeks. What does Garrett have to say about it?

jayc72

iTrader: (14)

Take the return fitting off and have a look. Is it the same fitting from the first turbo that bit the dust?

psiturbo

iTrader: (1)

Do you have a mechanical pressure gauge?

Wow, two turbos in 3 months, mmhh!

I do not think is the restrictor, I got a T3/T4 with a EGAY type restrictor and so far works very well on a "CHINA" turbo. Anyway see if you can take it to a hydraulic shop so they can test the braided line, those "braided" lines are made out of some hard white plastic on the inside, I have seen under very extreme heat (especially if the touch the turbo manifold) they buckle/collapse preventing oil from getting into the turbo.

Let us know how it goes, turbo projects every now and then shows its gremlins, best of luck!







Two different oil feed lines:

The left oil feed line (unrestricted) is from an RX7 Turbo II

The one on the right (silver) is the one I use, our cars deliver 40 + psi under hard acceleration. The fitting is meant to restrict to 15 psi (if I recall well).


A closer look to the one I currently have installed, bought from EGAY on a china turbo.

It is not the same car, Mazda Protege, it uses the same engine 1.8 DOHC, also the orientation is transverse instead of inline with the chassis.

NA6C-Guy

iTrader: (1)

Don't ignore the signs, someone is trying to tell you to forget about turbos...

miataspeed2005

iTrader: (3)

It has to be either the banjo bolt or the restrictor that it's clogged. I would Aldo check if the whole on the side of the banjo bolt lines up with the oil feed line. I know there's different banjo bolts with different side hole locations and lenghts. And you may want to consider getting rid off banjo bolts period. That's what I did on my turbo

gianic

iTrader: (6)

If I find him I'll put my broken chra in his butthole....





....without lubricant


Psiturbo I'm going to measure the pressure of the oil feed at idle. Good idea.

The restrictor and the banjo bolt are not clogged. Oil flows normally through them. I will get rid of them as soon as the new turbo arrives.
But I dont think that this is the problem..

sixshooter

iTrader: (12)

Banjo bolts are not the problem. Factory turbos have them. Aftermarket turbos have them. Most automotive brakes have them. There is nothing inherently wrong with them.

You obviously have some other oiling problem.

I will agree with what was posted previously that taking the wastegate signal from the intake manifold is a problem and must be changed. It may or may not have contributed to the failure, but needs to be changed. The wastegate signal must be taken before the throttle body and preferably after the intercooler.

If the wastegate signal is taken from the intake manifold then at part throttle the turbo is making nearly unlimited amounts of pressure and heat on the compressor side and also severely restricting exhaust flow. If the compressor is seeing no relief from the pressure then it will be fighting with the turbine which will be creating pounds and pounds of superheated backpressure for the exhaust manifold and turbine. Without a pressure reference in front of the throttle, nothing will tell the wastegate to stop making pressure.

dustinb

I just noticed as well from the picture he posted that his turbo has a vacuum reference on it for the wastegate. Use that!!

I would disconnect all the lines to the turbo (feed and drain), plus all the fittings. Give it a visual inspection and see if there is anything in there that has clogged it. Then I would get some oil and just dump it in the top hole, and see if it falls out the bottom.

gianic

iTrader: (6)

Τhat was the 2560r. 2871 didnt have that port.


Sixshooter I like your explanation very much, and I'm sure the destruction came in part throttle.
But as I mentioned above, with the 2560 I had the boost signal from the compressor housing so that wasnt the problem on the first failure.

dustinb

Has to be an oil issue then, if you had same thing happen to two turbo's, and were using the right boost reference on one of them.

Stephanie Turner

If you send the turbo to ATP they can evaluate it and (9 times out of 10) tell you what caused the failure. Just cause I am paranoid, when we switch out a broken turbo for a new one, we always do new a oil supply and oil drain line. And possible new coolant lines, depending upon the reason for the failure.
Stephanie

thagr81 us

iTrader: (5)

The white material is Teflon. The braided stainless steel is to give it protection from abrasion and help with preventing swelling of the tubing. But yes, under extreme heating conditions, Teflon tubing will "pinch" closed and restrict or stop flow. Try pouring some oil through the tube directly and see if it flows through at a steady rate. Could give you another idea... Just a thought.

gianic

iTrader: (6)

Got my new turbo from atp and I mounted my egt sensor near the collector. (before it was on the dp) They didn't mention the fault.

The readings from the egt sensor were scary. 1796f peak temp. I think this is the problem because I'm quiet sure I read somewhere that the ball bearing temp limit is 1700f.

m2cupcar

iTrader: (5)

I think you need find out what ATP says about the EGTs for that turbo. A turbo engineer recently posted that modern gas OE turbos run operating egts from 950-1050c depending on the turbo/application. Post here.

Slayer

iTrader: (6)

+1

and I'm guessing if you couple this with marginal oiling, rapid failure would ensue.

Good read:
https://www.miataturbo.net/forum/t32479-2/