cygnusx1

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

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!

Nice car! White is my new favorite color.

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.

It's a 5 speed. Compressor side is bone dry. Confirmed at housing

Gotta get my nomex gloves ready. My O2 is close to the turbine exit. About 3" away, so it is a good point of view for sure. It makes sense that if there was smoke there shortly after shutdown, it's likely not coming from the combustion chambers. Yeah cold starts are always very clean, do a hot restart shortly after shutting it down and you get a big blue cloud that clears with a rev or two. On that note I suppose it's easy enough to pull the down pipe right off, and cycle it on-off and look inside. Maybe my cloths don't smell like burnt oil after all. It must be carbonizing oil. Is it pungent?

I have always had dry gasketing with Permatex #2 on both sides of the gasket. It's made for this exact purpose. Clean surfaces with Windex, apply goop to both surfaces or gasket, and assemble with finger torque. Go back in a couple of hours and torque to spec. #2 stays a bit pliable so it continues to seal. It's easy to remove later too. I don't think it's good for exhaust work. I wouldn't use it there anyhow. I also used it for the rear main cap corners, and oil seal lube/sealant during install.

Yes, I could do that because I run MS, however, the compressor side is bone dry. I think if it is leaking, it's on the turbine side, I can't think of an easy way to take that out of the equation. Thanks for the idea though! LOL. I thought about performing my 30 second hot restart with the nose of the car down hill and then uphill to see if there is a difference. I know it's a reach but....at least i am thinking.

My original line lock, locked in the up position, or open position. I called Dave at AZC and he promptly sent a new one. I took the old one that was locked, and squeezed it in my vise. Fluid came squirting out of it, as the button freed up. I think fluid gets around the "seal" internally, over time. I don't think they were engineered for long term use. back to original topic.

I am going to test everything no matter what. But I am hoping that my hunch is correct, and that the turbo has exceeded its usefulness. It's a unit that was "rebuilt "at least twice now. Generally when you have a problem after changing something, the first thing you do is blame the work you just did. In my case, piston rings and turbo seals were messed with. I have much more faith in the work done on the pistons than the turbo. I will get to the bottom of this next week.

Yeah sorry, rod bolts were set to 45 by the sheet that came with the bolts. Head bolts set to 60. Mains are factory. I followed ARP's instructions and used their moly. Good catch!

No, I am waiting for a compression tester. The piston rings are ITM as part of the ITM piston/pin/ring set. They were all gapped in the respective bores to 0.017". The gaps were staggered, alternating 180 degrees, all of them above the skirts. Oil control rings and gaps were confirmed properly setup before I clamped the ring compressor on them. The plugs are super clean and dry. I have heard that turbine seals will leak all the time if bad, but will leak most off throttle; similar to valve seals. They will pool oil in the turbine, to be burned off again, if the car is fired up hot again, a short while later. Next chance I get, I will pull the downpipe and look in the turbine housing for play and grime. So far, based on the great vacuum readings, strong power under load, with no visible smoke, and clean plugs, I think the piston rings are good. When I changed the ring seals and bushings in the turbo, I was not thrilled with the conditions of the ring groove and shaft. I did not document the measurements because I had no reference anyhow. They just looked a bit pitted and dull for precision fitment, to me. It probably smokes worse now that I cleaned all the coking out of it for the rebuild. I am tempted to plug off the turbo oil feed line and do some brief tests....bad idea or REALLY bad idea?

The challenge of setting up, and driving triples...and the reward! +1

Yeah Joe, good idea. I did this test and I need some help interpreting it. -Cold start, zero smoke. -Hard acceleration, zero smoke. -Heavy deceleration, smoke. -Hot idle, little to no smoke. -Shut down hot, and restart in 30 seconds, big cloud of blue smoke after start and rev. <---------- turbo seal dripping into turbine?

I just added a restrictor the other day with no change in conditions. I am waiting on a compression tester which I think will show the rings are fine, hopefully... I mean, it runs great and the plugs are a beautiful color.

Daily Driver

It's simple to make a shield. Go to home depot and buy a sheet of galvanized steel. Make a cardboard template. Snip out the steel sheet, leave about 1" extra on the drivers side, front and back. Fold the 1" extra down all the way around to stiffen it up. Use a vise and a hammer. There are a few places directly under the carbs with tap holes, and/or the retaining screws for the bowl drain covers. Attach using one of those methods. I lined mine with foiled fiberglass mat. Carbs are always cool now. Note: the inboard edge of my shield is pressed up against the header and intake, which holds it in place there. I used copper pipe to make stand-offs under the carbs. My only gripe is that I didn't use fuel proof paint on it. Now it looks like a$$ from the runs in it.

Thanks, but my track day budget is wiped out now.. The motor is smoking a bit more than I would expect on decel too. Still trying to figure out why. http://forums.hybridz.org/index.php/topic/100026-rebuilt-motordecel-smoke/

I added a hose from the valve cover to the turbo inlet so that the PCV system should operate at well as the factory system did. I put on another 80 miles or so. It still smokes pretty good blue fog on decel from anything above about 3000 rpm. The plugs still look awesome and it runs really well. COmpression test will be next, followed by a courtesy valve seal change. I have at least three sets of new valve seals around. If compression is good, and valve seals don't solve the smoke, the turbo will get a new owner. Tapped into the turbo inlet pipe for the valve cover vent. Cheap and effective. Edit: I went back and checked the photos of the ring installation and it all looks good against the supplied chart. I specifically remember making sure the oil control spreader was not overlapped before placing the pistons in the block. I keep second guessing myself. (huge photo here: http://dcer.smugmug..../O/P1060561.jpg )

Turbo compressor side appears clean and dry but I see some wetness around the end of the cartridge where it clocks to the turbine housing. I installed a restrictor in the oil feed line and checked torque at all the fittings. Will test tomorrow. I suppose I really need to give the rings more time to seat before I diagnose any further. I'll put on more miles tomorrow.

I'm going to pull the turbo outlet pipe to have a look. The plugs look so much cleaner than the grimy ones that i pulled out of the motor prior to the rebuild. In fact they look perfect now. I tend to think, that the plugs are not seeing any oil, based on their clean look compared to how they used to look. (same set of plugs). I hope it's the turbo because I won't mind letting it be for a while, if so. The top plug in this photo, represents what my plugs look like now. The oily one, represents what they looked like when I pulled them out before the rebuild.

The L28ET that I just rebuilt runs great. I put about 70 miles on it today "break in style". I have a concern because it smokes a little on decel. I am going to give the rings some more time to seat but I don't think it's ring related. I pulled the plugs and they are the nicest, light brown, dry, color I have ever seen in the car. That tells me that it might be the turbine seal. I figure when the engine is under load, the exhaust back pressure keeps the oil where it belongs, in the turbo core. On decel, the oil might be dripping into the turbine and making the blue smoke. It happens mostly when I come down from 4000+ rpm. When it coasts down to about 2000, the blue smoke begins to trail out. The head has only about 5000 miles on it since the rebuild, and the car does not smoke when it starts. I rebuilt the turbo during this engine build, but the shaft was a bit "rough" and pitted. I was not entirely happy with the shaft condition but I figured I would try it. I also didn't like the "looseness" of the seal on the turbine side. (this may be just me pointing the question). Does it sound like the turbo might be bleeding oil? Are there any other tests I can do? If I had a compression tester I would do that. The vacuum at idle is as good as I have ever seen it....and the plugs looks perfect. It smoked before the rebuild on decel too. I have the PCV valve connected to the block vent with some stainless mesh in the pipe, and have the valve cover vented. Upon doing some reading, I have to look into a better PCV layout, and an oil line restrictor. I am using the factory oil pipe right now. I also read that the new turbo seals need to build a "carbon dam" before they seal up well. Is that true? Dave

Dead head fuel line seems to work well for me in both of my cars. I realize that there are "potential" problems with dead heading, but I have no issues. Speaking of fuel line, take a length of it, stick one end into the carb intake at idle, and listen to the other end. Make them sound the same and you are generally close enough...if you have a decent ear. It works. Alternatively, you can get close by looking down into the progression holes and visually adjusting the throttle stops so that the plates are all just downwind of the progression ports.

Boring video of my first engine rebuild having just been fired up. I have the idle up with some feeler gauges under the throttle stop. I was told you don't want the engine to idle too low at any length of time for it's first few runs.

Houston, we have ignition! Smooth startup today, good oil P, no leaks, break-in drive tomorrow.