The AFR was steady in the low 12's throughout the pull at 10psi

1995 base model
BEGi-S kit with BEGi intercooler
MSPNP2
175k stock internals
650cc Ev14 injectors
Highflow 2.25" cat
2.25" supertrapp uncorked off of cat dumping in front of rear axle
spring and ball MBC
new but stock clutch

The car exhaust is smoking a fair amount on the dyno so we only did 1 pull, the exhaust didn't smoke before the turbo install. The engine itself before the turbo install is a little tired but healthy with acceptable compression. I don't think it's the oil return line, it seems to be mounted properly in the pan correctly and is of sufficient gauge to do the job. The dyno tech and I believe the used garrett turbo I have has bad oil seals which is letting oil get pushed thru the intercooler into the intake. The previous owner of this BEGI turbo kit mentioned he added the oil restrictor to the feed line... which means he must have ran it for a while without a restrictor, we believe he probably blew the seals out at that time. There is evidence for this as the clamps holding the intercooler piping together show signs of oil weeping through the joints as oil is pushed through to the intake. I did some thread searching here and the previous owner of this kit also had an issue with oil getting into his intercooler tubes, it's all sorta making sense now. I am going to see if I can have the oil seals replaced on the turbo. It doesn't seem to smoke nearly as much when I am driving the car on the road and not on a load dyno being torture tested. The tech recommend the folks at ATPturbo to look at servicing the garrett turbo to see if the oil seals are indeed bad and need replacing, they happen to be local to me, anyone have any experience with them?

 

You just installed this?

Check your oil drain line. Needs gravity.

I had a 2554r with a bad seal. 007 style smokescreen. https://www.miataturbo.net/diy-turbo-discussion-14/turbo-ruined-56181/

 

Thanks you for the response, yes I just installed this. I read your thread, I have the same exact problem you were having. I seem to be able to make boost just fine even when it is smoking, it will spin up to 15psi with no issue besides a spyhunter haze behind me. It looks like the ballbearing garrett's oil seal is supposed to let oil by if it can't drain fast enough, maybe my oil restrictor isn't small enough? Did your oil restrictor solve all you issues?

I'll try a smaller restrictor as my first step since that is an easy thing to try before I attempt to pull the turbo and have it looked at. The shaft play seemed normal to me when I installed it, but it's the only turbo I've ever touched so I have nothing to reference it to. I have checked the drain line and it seems to be fine, it's a straight shot into the pan. I only have a few pics that show from the build that show drain line.




P.S. Those are pics from last week, I no longer have the valvecover vent line running to the intake, it has a filter on the valve cover side and sealed at the intake side. The egr and pcv line is also blocked.

 

As I do more research it looks like the Garrett ball bearing GT2554r turbo is not rebuildable. It seems the best way to revive a bad sealing ballbearing turbo is with a new CHRA, the best price I have found on that is here:
http://www.conceptzperformance.com/C...1766.249.65.28

If a recheck of the drain line and a smaller restrictor doesn't work I may have to make the choice to refresh this ball-bearing turbo with a new CHRA or get a cheap churbo and call it a day.

 

I think this was the turbo on my car that I sold a few years back. ATP is probably going to tell you the same thing when I brought it into them to look at when I had saw smoke one day: it's likely not the seals, check your oil feed and drain line. I still paid them to look at it and they said nothing was wrong. Guess what, they were right. A few days before I tightened the oil drain fitting to where it was flush against a plate in the pan and the oil drain wasn't working right. This turbo had no smoking issues making 13-15 psi when I sold it.

 

Yup this is the same turbo, it had sat on a shelf in my garage till last month. Thanks for the heads up, I was going to do the same thing at take it into ATP to have it looked at... you saved me a trip. I'll definitely check the drain line tomorrow, if I read you right you said there was a plate inside the oil pan which obstructed the return flow when the return line tapped piece is threaded into the oil pan too far? You backed off the drain return fitting and the smoking went away? The fitting on the pan definitely will thread in pretty deep I remember.

 

That's exactly the problem. I noticed the fitting was a bit loose one day and was trying to track down an oil leak (ended up being something else) so I tightened it up. This pushed it against something in the pan and obstructed the drain. Check that the fitting is above the oil level (should be) and try taking the fitting out and looking in the pan to see if it's hitting something. The smoke went away immediately when I backed the fitting off to where it was originally. It saw several track days and street driving after that with no issues.

I took the kit off because I had to smog the car. Got frustrated after taking off the the BEGI manifold and downpipe and decided to sell the kit instead of putting it back on...

 

Lol I hear you about taking that manifold and DP on and off a lot is a pain... especially when I hadn't figured out to bolt the turbo to the manifold on the bench yet, that task of bolting those together under the hood cost me 3 hours and two ground down hand wrenches to complete. Now that you mention it I seem to recall that when I was pouring the mineral spirits down the return line to clear the shavings that the fluid backed up into the funnel i was using a bit, because i remember it leaking into my hand where i was holding the funnel to the drain line... duh that shoulda tipped me off right there that something is amiss. Sorry if I had an accusatory tone before, I never got to the part of how you resolved the oil in the intake when I found that thread before, I prejudged the situation a little bit I admit. I probably should have just PMed you in the first place, thanks for the insight.

 

Unscrew your oil feed and post pic. Restricter fixed my issue completely.

 

Worth checking the restrictor as 94mx5red said. When I had the smoke issue was the same time I installed the restrictor thinking that would fix the problem. It definitely reduced it (less oil to burn over time), but didn't solve it. If you used the restrictor I gave you (orange fitting between feed line and turbo inlet) it's a .035" from ATP.

FYI, the metal plate in the pan was the windage tray. If you back off the fitting the threads won't seal as well since it's NPT (seals on threads) and since it was screwed in far the hole is wider. It should only be a few turns into the pan and shouldn't be sticking in all the way like in your pic.

 

You need a 3" exhaust badly. I had almost the exactly the same setup as you except for ms1, rx7 injectors, and a 3" Enthuza exhaust. I made 200hp 200ft/lbs at 9.5psi on a dynopack. I think with the 3inch exhaust you will pick up a good bit more at the really low end and a good bit more top end.

 

Here is the restrictor:


I pulled the drain fitting out of the oil pan and there was nothing inside close to blocking it, I guess the 1995 model doesn't have the same windage tray inside as the 1996 model has or you drilled into a different spot than I did. I stuck a wooden dowel into the hole to see how deep till it hit something and it was a good 1.5" at least till an obstruction, so my issue isn't that.


I tried backing off a few threads anyways just for giggles to see if it might solve it anyways. I used rubber gromets to be able to get it to synch with less threads, it didn't help.


I thought that maybe I drilled the hole in a spot that might be stretching the braided line and making it kink inside somewhere, so I added a little 3/8" NPT extension to ease the tension on the drain hose in case the spots where it has started to chaff are kink the hose inside when it makes the bend from vertical to horizontal. I even flipped the drain hose to the part with the braids chaffing was in the straight drop out of the bottom of the turbo and not part of the bend into the pan. Did't help it much though.


I also moved the drain line so it is behind the powersteering line rather than in front of it and has a more direct gravitational shot straight down out of the turbo.


None of these things helped the smoking issue much though, my next step is to get a smaller restrictor and swap out the braided drain line for the largest gauge rubber hose and -8AN or 3/8"NPT to hose bard fittings to run a new drain line from the turbo to the pan to see if that helps. I have a feeling this braided line I have is somehow getting pinched inside.

I would assume once I solve it a few boosted runs would push the oil in the intercooler out through the engine and things would clear up. It' seems to be getting worse, maybe the intercooler is filling with oil or maybe I am just paying more attention to the rear view mirror watching for a cloud of smoke now. Here is a video of the phenomenon. :(



It's hard to see in the video, but a little smoke is also coming out of the valve cover breather filter and a little bit from the turbo to DP flange. Smoke from the valve cover breather filter is a little disconcerting, is that the combustion smoke getting past the rings and valve seals?

Then after all of this I was driving on the freeway and the car suddenly lost power, it was still running sort of but when I got on the throttle not a whole lot happened, it felt like it lost most of the spark for about 5 seconds, right as I flipped on my emergency light to make a mad dash across to the shoulder from the fast lane everything came back to normal and the turbo spooled back to life again. It happened right after a full boosted pull, maybe the plugs got fouled with oil for a moment?

 

My drain line went directly under the turbo to the middle of the pan.

 

Alright I'll try that next, drilling a new hole in the pan was definitely one of the options I had on my list before i ran out of time today. The only reason i put it in that spot is that's where the BEGi instructions say to drill it, logically straight down under the turbo makes way more sense. My plan will be to drill it directly below the turbo and as high on the pan as I can get it to be above the oil level. I wonder why the BEGi instructions say to drill it so far forward on the pan?

 

I am considering swapping the entire oil drain hose for a larger gauge setup. Here is my idea:
Replace the BEGi threaded 3/8" NPT oil drain plate with a ATP 5/8" barb oil drain plate and gasket, then drill the middle of the oil pan with a 23/32" bit and tap it with a 1/2-14 NPT tap for a 1/2" NPT to 5/8" elbow barb, finish it up by using a 5/8" high temp drain hose. This would be the largest diameter oil drain system for the GT2554r with the least amount of restriction, AFAIK.

 

It is because that is where you can fit a drill in when you have AC/PS. The spot at the front of the pan has been to go to spot for to drill and tap for well over a decade. The only time that people recommend drilling further back is if you have the oil pan off the engine and can easily do it.

 

Here is a cutaway of your turbo:

I collapsed the ring on the exhaust side in my turbo but smoke only came out the CHRA/turbine housing joint.

I can't tell, does the smoke increase with RPM? How long did the car idle or did you drive it after adding the restrictor? Its possible that oil "over-flowed" the rings and its pooled in the heat-shield/CHRA area and will burn-off.

Is there any chance you overfilled the engine with oil?

Why haven't you fixed your front main seal?

Is there any oil mist on your blow-off-valve? That will tell you if oil is going through the compressor side.

 

Thanks for the view of the inside of the turbo so i can see what's going on. I do believe that the smoke gets worse as the RPM's go up, it has always had the restrictor on it for my install. It's getting worse not better, I don't think any of the drain line fixes I attempted helped anything yet.

I have overfilled the oil before, so I know what that looks like, that was a lot of smoke when I did that, this isn't as much smoke as that. It's was down a quart when I checked it yesterday, which means right now I am burning about a quart every 100 miles.

I'll fix the main seal when I get around to doing the water pump and timing belt, but yes it does make for a greasy oil pan.

I'll check the Bosch by-pass valve which dumps to atmosphere for oil, I am also going to crack open an intercooler joint to peek in to see if theres lots of oil residue. I believe there will be, because I can see the oil seeping through on the joints holding the intake tubes together. But maybe I have this all wrong and it's dumping oil the other direction into the exhaust side of the turbo, the one thing that confuses me is that the car makes decent power and the turbo seems to be spooling and making boost just fine, I would seem to me that if that much oil was going through the intake it would run a lot crappier than it actually does.

Before I give up and pull the turbo to have it checked again at ATP I am going to increase the drain line to 5/8" from the turbo all the way to the pan to completely rule that out as the cause.

 

The smoking is getting worse, although power and boost seems alright. I took the apart the intake hoses to inspect them and the intercooler and they are all bone dry, no oil to be seen inside them. This means my whole theory of oil getting into the intake causing the smoke is wrong. The oil smoke is either being generated internally inside the engine or on the exhaust side of the ball bearing turbo.

I installed a larger ATP 5/8" barb drain plate at the turbo all the way to a 1/2" NPT fitting at the oil pan, the mineral spirits had no problem draining thru the funnel into the pan this time. It didn't help solve the smoking for now but I did it to eliminate bad oil draining as the cause of the smoking issues.

My next step will be compression check the engine to see if it's still decent on all cylinders . If that checks out then it's time to pull the manifold/turbo and downpipe and reinstall the stock exhaust manifold to see if the car still smokes without the turbo, maybe the engine is on it's way out and that is what needs to be replaced. If it doesn't smoke anymore without the turbo I may call ATP to get the GT2554r looked at. I read conflicting reports about rebuilding ball bearing garrett turbos, some say they can be refreshed with a rebuild kit, others say only thing you can do is get the CHRA replaced, which is at least 50-60% of the price of a brand new BB garrett turbo to my understanding. I see "rebuilt" ball bearing GT2554r turbos on ebay for around $500, would that mean if rebuilt properly they should have new CHRA's?

 

do the compression check.

for my gt2554r I used pipe thread to -10 AN fittings in the pan and for the drain and -4 AN for the feed with the ATP .035 whatever restricter. No smoking and my drain line is just run down there, no real urgency to it...

they are right, it sounds like something else is messed up. maybe the PCV into the intake manifold is dumping oil in or not venting right causing blowby.