cygnusx1 Posted May 16, 2011 Author Share Posted May 16, 2011 (edited) OK I ran a compression test, hot with WOT. All cylinders came up between 138 and 141 with five compression strokes. The motor only has about 230 miles on it. since the build. Those numbers seem low, but then again it's probably not fully seated yet, and they are all consistent. EDIT: FSM calls for 142psi so I am right there. I took out the O2 sensor and ran in the garage with the bung open. When the car was cold there was no smoke at all. After it was warmed up as much as I could get in the garage, it began to smoke on throttle shut, if I held the motor at about 2500 for 20 seconds or more. The smoke came out of the O2 bung and tail pipe. Hot restart produced some smoke but not as much as after a drive. The oil and turbine temps are much lower just idling in the garage. When I shut it down, there was no smoke from anywhere. With the bung open, I can hear a rattle in the turbo when I rev it up a little. It sounds like the turbine moving around and either thrusting against the bushings, or actually hitting something. When I let the car cool for 40 minutes and started it, I got no smoke at all from the bung, or the tail pipe. Again, I think it's because the turbine is cool and does no burn any pooled oil yet. Looking in the bung, I saw nothing but clean pipe. No liquid oil or coke visible 2" downstream of the turbine. I also just thought of something. I plan to go in to change the valve seals but is it likely, when cylinder #4 sucked coolant at the track, that the coolant punched a valve seal off? I never looked at them when I had the head off for the rebuild. I doubt it but worth a thought. Edited May 16, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 17, 2011 Author Share Posted May 17, 2011 This is interesting. Tomorrow I'll pull the turbo out, dismantle it, and confirm a few things. Here is some enlightening info...to me at least. http://www.turbo-mopar.com/forums/showthread.php?51375-Why-turbos-leak-oil-into-the-exhaust-With-Pics! Quote Link to comment Share on other sites More sharing options...
effing matt Posted May 17, 2011 Share Posted May 17, 2011 (edited) This is interesting. Tomorrow I'll pull the turbo out, dismantle it, and confirm a few things. Here is some enlightening info...to me at least. http://www.turbo-mopar.com/forums/showthread.php?51375-Why-turbos-leak-oil-into-the-exhaust-With-Pics! Your turbine side piston ring (oil control) has probably collapsed. You should be able to find a rebuild kit for less than $50 as long as there is no damage to the pistong ring groove or the piston ring step on the center housing. PM me if you have any turbo disassembley or re-assembly questions, I'll be happy to walk you through it. Be sure to pay careful attention to the orientation of the wheels and balancing cuts on the compressor nut. This can cause noise and/or bearing issues after re-assembly. Also the compressor nut is probably a left hand thread, so righty tighty, lefty loosy isn't always correct when it comes to turbo chargers. EDIT: I just re-read the thread and saw where you had already re-built the turbo. Did you measure the gaps on the piston ring on the shaft (side clearance) or the end gap (while the piston ring is not on the shaft and pushed into the bore of the center housing? Start with those measurements and I can probably give you some guidance. Edited May 17, 2011 by effing matt Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 17, 2011 Author Share Posted May 17, 2011 (edited) Well I took the turbo apart again tonight and it really doesn't look THAT bad. There was oil creeping out from the seam where the turbine housing meets the cartridge though. The back of the turbine heat shield was a bit oily too. I measured up the turbo because I had no specs other than it was a T04B Super V trim. I did not measure the piston ring side clearance or the end gap. I will do that tomorrow and post it. I have no idea what they should be so I didn't bother to measure. The ring fits in there snugly and I watched the end gap close up as I seated it into the housing. The compressor side was clean and dry. The cartridge was clean with a wide open return path for the oil. Here are my turbo specs for archival's sake. T3 Turbine 67 Trim with a 0.63 A/R housing T04B Compressor with 69 Trim as best I can measure. Shaft size 10.14mm at bushings, and 6.33mm at tail. Major shaft size next to ring seal groove 17.26mm Exhaust Seal bore in cartridge 18mm I am running a 1/8" restrictor and will reduce to 1/16". What do you guys think of this seal as an upgrade while I have it apart? http://cgi.ebay.com/ebaymotors/T3-T4-Turbo-Stagger-Gap-Turbine-Shaft-Seal-_W0QQcmdZViewItemQQhashZitem5d2eb81503QQitemZ400215774467QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Edited May 17, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
JMortensen Posted May 17, 2011 Share Posted May 17, 2011 I'm still thinking the oil rings just aren't seated. I'd reassemble and then drive the piss out of it (redline it, let off gas, redline it again, etc) for a day or two and see if the smoke goes away. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 17, 2011 Author Share Posted May 17, 2011 Jon, I hope that's all it is and that they do seat. When this seven day deluge stops, I'll get more miles on it. I chucked the turbo shaft in a drill and polished up the bearing surfaces, and cleaned out the ring groove. I measured the turbine seal fitment. End Gap 0.002", Side Gap 0.009". Shaft axial play 0.001", radial play 0.010". Then I took some photos. They are scary looking under my phone's amazing macro lens. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 17, 2011 Share Posted May 17, 2011 I know what our inspection section would say about that shaft... It appears on the back of the turbine wheel that you have radial streaks (oil staining)...not looking good. Let's see what happens with a new seal set. Good Luck! Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 17, 2011 Author Share Posted May 17, 2011 (edited) Thanks Tony. I hope this is the issue. I'll gladly toss this thing into the puddles if it's the cause of my smoking problem. Hmm this my be the creek paddle I am looking for! Made in China but looks way better than what I have now. http://cgi.ebay.com/...sQ5fAccessories Edited May 17, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
effing matt Posted May 17, 2011 Share Posted May 17, 2011 The side gap should look more like .0015-.004 range, that shaft shows a ton of wear. I would imagine that the compressor side of that unit is in pretty sad shape as well, it may be time to make a move to a new turbo. Check your PM's. Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 17, 2011 Share Posted May 17, 2011 Holy Hell! I just re-read that... I've been spending WAY too much time on big machines. Yeah, 0.009" side gap is huge! I would consider chucking it just on the shaft condition, that side gap is excessive. As an example, on a machine runnning 54,000 rpms and having two overhung rotors of 18" and 8" diameter total Axial movement of the rotor assembly is limited by thrust bearings to 0.006-0.008" MAXIMUM! Your little guy has as much clearance as the HS Rotor on a 2500HP machine! Just to put that in perspective. I read another "0" in there, and thought it was 0.0009"! (Tight one-thousandths feeler...) Gawd that shaft looks terrible. Good luck with the seal, maybe it will hold together long enough to get your E-Bay unit and do a replacement. Zero Driving Downtime is a good thing! Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 17, 2011 Author Share Posted May 17, 2011 Yeah the ebay turbine and shaft are on the way. The new seal will go on that sucker. I'm not going to bother putting that old rusty spear back in the snail. I'll drive the triple 240Z around for a while...if the rain ever stops. F'ing Matt, I'll check the PM and thanks! Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted May 19, 2011 Share Posted May 19, 2011 Mind if I ask what was done for the engine rebuild? If it smoked before rebuild, and you have a new turbo, then possibly the valve guides are worn (vacuum pulls in oil). What kind of valve stem seals did you use on the rebuild? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 19, 2011 Author Share Posted May 19, 2011 (edited) The head was rebuilt not long ago by a respected shop here locally. I believe fel-pro seals were used. It was done about 5000 miles ago. The pistons, rings, pins, bearings, timing kit, were all replaced two weeks ago by myself. The block was bored and honed 0.020" over. I verified piston clearances and ring gaps before I put it together. Compression readings are perfect. It smoked a little before this rebuild only on decel. During the rebuild, I decided to changed all the turbo bushings and seals. I noticed that the turbo shaft was not pretty but i figured it could not get any worse by changing seals and bushings. I think I was wrong. By cleaning out all the carbon from the turbo, I made it easier for oil to get past the seal on the worn shaft. Yes, it could be leaky valve seals but after studying the turbo shaft closely, why would I blame anything else, until this was fixed. I think that turbo shaft was pulled from a sunken offshore racer and "cleaned" up to use in my "rebuilt" turbo when I bought it a few years back. Edited May 19, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted May 21, 2011 Share Posted May 21, 2011 How is the turbo drain to pan flow? If this is restricted, it can cause oil to seek exit into the exhaust or intake side of the turbo. Excessive crankcase pressure can also cause this but this would cause smoking most all the time. Quote Link to comment Share on other sites More sharing options...
RB30X Posted May 22, 2011 Share Posted May 22, 2011 How is the turbo drain to pan flow? +1 Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 22, 2011 Author Share Posted May 22, 2011 (edited) The turbo, drain, pan fitting, tubes, and cartridge, were all cleaned up during the rebuild. All block vent's and PCV parts are hooked up and functioning. It's most likely the bad turbine shaft, and the oil control rings not quite seated yet. Possibly, some valve seal leakage also, even though the head was built 5000 miles ago. I will start with the new turbine shaft. Then I'll drive the snot out of it for a week or so. If it still smokes, I'll do the valve seals. The new turbine and shaft are sitting in customs.... Edited May 22, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 23, 2011 Author Share Posted May 23, 2011 (edited) Fresh from China! Back to the garage...but the left handed M6 nut was not specified. My old shaft is a 6mm RHT. More waiting for a nut. ..M6L, or is it 1/4-28...left hand? Edited May 23, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 23, 2011 Share Posted May 23, 2011 Got a thread pitch gauge, it will tell you straightaway! THAT looks a lot better! Though I'm not enamored by that balancing mark...wow... Quote Link to comment Share on other sites More sharing options...
effing matt Posted May 23, 2011 Share Posted May 23, 2011 Got a thread pitch gauge, it will tell you straightaway! THAT looks a lot better! Though I'm not enamored by that balancing mark...wow... That's about as nice as you will see from Garrett, it'll do just fine. If it were on a billet comp wheel, then I would worry. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted May 23, 2011 Author Share Posted May 23, 2011 (edited) The balancing mark is a lot shallower than it looks in the photo. I am almost positive the thread pitch is 28 tpi. Don't have a pitch gauge. I used a 1/4-28rh tap. The turbine wheel is inconel. Edited May 23, 2011 by cygnusx1 Quote Link to comment Share on other sites More sharing options...
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