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-   -   Running on fresh rebuild, but lots of white smoke (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/running-fresh-rebuild-but-lots-white-smoke-661885/)

toplessFC3Sman 06-13-07 07:48 AM

Running on fresh rebuild, but lots of white smoke
 
I just got an S4 TII engine back from being rebuilt and finally dropped it into my 88 'vert and hooked everything up. After a bit of fiddling with the wideband, a few sensors, and the megasquirt, she's firing up very quickly and consistantly. Yay! Now for the bad... I have a LOT of white smoke pouring out the exhaust (and a little leaking out of somewhere around the turbo, I cant tell where cause the fan blows it all around.)

Now, my first thought was that an oil seal in the turbo was completely shot, because the amount of white smoke seemed to be dependant on the oil pressure. I didnt notice anything in the compressor side, and I haven't taken off the turbo to inspect the turbine for soot & build-up.

A bit of history on my setup, hopefully to avoid some confusion... it was on the engine when I bought it (sitting in a field in VA, $400 for manifolds, engine, turbo etc). It's a hybrid, stock S4 center and turbine, with a T04 compressor. I dropped that motor as is into my 'vert, but swapped a fully stock turbo on, and popped that motor pretty quickly (at 4 psi... i guess the 88 'vert ecu doesnt do a great job at controlling it after all). It came out to get a rebuild, so in the mean time I took both turbos apart to inspect and port the wastegates. The fully stock one had a severely cracked hot-side housing that was chewing up the turbine blades, so I went ahead on the hybrid, cleaned it up (lots of black junk, especially crammed under that can/bell type thing between the turbine wheel and center section), ported the wastegate and welded on a washer to the flapper, and threw it all back together. Now its on the car and white smoke is spewing out the exhaust.

I really think that this is a real bad oil leak on the turbine side of the turbo, but I wanted to get the advice and opinions of those on here that have more experience than I do.

Cliff Notes:
Fresh rebuild, new EMS, S4 TII engine, T04 hybrid... start it up and it spews white smoke proportionately to the oil pressure. No oil in compressor side of turbo (that I can see anyway), but otherwise untested turbo. Engine seal leaking or turbo hot-side leaking?

bigdaddyp 06-13-07 09:17 AM

alot of white smoke is a sign of coolant seal failure, or internal turbo seal failure. I BELIEVE. I would say, fresh rebuild, then it must be turbo seal.

digitalsolo 06-13-07 09:40 AM

Are you loosing coolant? Does the level drop as you run it?

I'd ask if you've smelled the exhaust, a coolant leak will have a nice, sweet smell to it. It's not uncommon for a rebuild to smoke slightly on first fire up, but from the sound of it, you have dramatically more then "slight" amounts.

Most likely hosed a coolant seal on the rebuild. :(

toplessFC3Sman 06-13-07 10:35 AM

Im almost positive that its not coolant... it certainly doesnt smell like coolant coming out the back (my old NA engine burned a little at times, and you could definately tell). This is smoking like... a cloud forms at idle behind the car, and once you rev it up, it becomes closer to a smoke screen. I didnt notice the coolant level dropping too much, but thats not really conclusive since it was dry before and still working out the air bubbles. i sure as hell hope its not a coolant seal in the motor, it was an Ito rebuild with new housings and the works, so it shouldnt be. I'm gonna tear the turbo off and apart after work today, so im hoping for a lot of crap in the hot side housing.

schmol 06-13-07 11:05 AM

fresh rebuild might have a fogging oil on the rotors. most engine builders will coat the inside of a rebuilt motor just incase it sits for a bit before it gets installed. How long have you run it since you dropped it in?

toplessFC3Sman 06-13-07 11:26 AM

its been running (idling up to about 3000 rpm, no load) for about an hour total. I was expecting a little smoke, but this is a lot. i'll take a picture after I get off work.

schmol 06-13-07 01:28 PM

If it was what I suggested, it should've only lasted for about 10 minutes or so.

toplessFC3Sman 06-19-07 07:35 AM

Ok, i tore off the old turbo on there and found that the center housing had a bit of un-repairable damage to the turbine seal bore, which I thought would account for the smoke. So I got a rebuild kit and re-built a different center housing I had laying around (btw, dont order from gpopshop.com, a lot of the stuff they sent just doesnt fit), and threw it back on the car. It started up fine, but then the smoke continued, but it seemed a little less severe than before. What else could be causing this?

How often do oil injectors fail or stick open? Their vac line connects to the larger nipple on the firewall side row of nipples on the UIM plenum, right?

toplessFC3Sman 06-19-07 10:02 AM

To add to this, the crank case was ventilated. At first it was T-ed with the charcoal canister line and run to the intake pre-turbo, and then it was disconnected and left free. There was no oil coming out of that line. There didnt seem to be a change in the amount of smoke, but at that point there wasnt any light left to really be sure.

lsimplicityj 06-20-07 02:30 PM

asasasa
 
I actually had this problem with my TII. The way i fixed it was a 12.00$ oil restrictor adapter for the turbo. It just screws into the oil feed line for the turbo. But then agian I am running a Gt35r turbo. So it might be different. My oil restrictor was pretty big. They sell small ones, just google them.

scrip7 06-20-07 02:51 PM

The rubber hoses to the oil injectors are for venting purposes only. They should not be connected to engine vacuum, but to the port on the throttle body that taps in before the throttle plates. Look to see if you have oil in those vent lines.

As for the smoke, if it's coolant it should be pure white smoke. Oil burning should have a bluish tint to the smoke. It also takes a little while for any oil buildup in the exhaust to burn out, especially if you are using cat. converters.


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