Hello--

Got a peculiar issue I'd like to brain storm. Though, some context will be needed.

In the last month, I've had some unfortunate events happen with the turbo tercel (4age, t25 NPR exhaust, eclipse intake turbo). I first popped the head gasket -- combustion to coolant failure, I had the oil feed coming from my oil filter adapter blow off twice, very briefly starving everything of oil, I also had an injector driver fail in my MS3x, again, and to round things off, the car is now dumping all of its oil straight into the exhaust. The engine weathered the oil starvation incidents fairly well, but the turbo did not. The head gasket was replaced with a cometic mls, oil feed lines converted to AN, and injector driver was repaired.

So, with the smoke screen, I first assumed the mls head gasket had failed at the #4 cylinder between the chamber and the oil jacket. Only the #4 cylinder and spark plug had evidence of burning oil, and I was trying to be hopeful about it not being the turbo. I didnt want to pull the head, so I loosened all the headbolt and retorqued them. No dice -- still billowing smoke out from the exhaust. Now, one may think that its just residual oil in the exhaust. While that may be true, I learned that the welds on my vband on the turbo has more holes than swiss cheese--there is smoke pouring out right at the turbo. Soooo...not residual oil.

After seeing no change with retorquing the headbolts, I then assumed one of the turbo seals popped out as there was excessive play in the shaft, and needed a fresh set of bushings and seals. Got a rebuild kit, put fresh bushings and seals in aaaaaaaaaaand no change. Not only did I see raw oil coming out of the pinholes at the vband, but as soon as everything got hot, that raw oil turned into a smoke screen.

I am leaning towards there still being a leak between the #4 cylinder and the oil jacket. If you look at the picture, the pressurized jacket is right next to the cylinder, and theres not much else that can push that much oil into the exhaust.

Thoughts?

Lets say it is a mls gasket failure due to the surface finish / RA not being within acceptable tolerances. Would you go back to a quality composite head gasket and run studs?

Attached is a YT short of it billowing smoke, and a picture of the head gasket showing the pressurized oil jacket.



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Pull all the plugs and see if it's one cylinder or all of them.

Check the IC and IC piping for oil.
If there are mufflers then they are filled with oil too.

Went through all of this a few years ago when turbo seals leaked several times and pumped nearly 8qts out of the pan. Had to get new mufflers and remove all the IC piping, IC, exhaust pipes, etc and wash it all out with gas.

ks

 

ill check again as it was pretty late last night when i tested it, but from what i saw, its only #4 that had signs of oil.

knowing my luck theres prolly some oil in the IC. the muffler is at the very back of the car and isnt the lowest point of the system, but i will still check.

however, its still billowing smoke at the v band, which rules out residual oil in the exhaust being the main source of smoke. my vband is welded to the turbo exhaust flange, so that really leaves the turbo or the head gasket. my local diesel and turbo shop cant do a pressurized oil check on the turbo, so I'm kinda stuck on knowing if its a turbo seal issue or not.

 

Don't underestimate where raw oil can go. The exhaust pressure will blow oil vapor through everything... I have full length exhaust with three mufflers and it was blowing raw oil out the tail pipes.
I also poured about 1qt of oil from the IC alone.
My incident may have been more severe than yours but keep this in mind so you don't start chasing your tail looking in the wrong areas.

ks

 

i feel like if it was sucking oil from the ic, itd be smoking in bursts or id see oil residue on all the plugs, not the #4. I may pull the turbo off again and see if theres oil in the manifold. though, that may not be a definitive sign as i would imagine the inside of the manifold would stay hot long enough to burn all the oil out before it cools down.

 

update:

so. checked the plumbing at the turbo. IC plumbing is clear, exhaust pipe is soaked.

pulled the turbo off the car whilst leaving the oil lines still connected. no evidence of oil in the engine exhaust manifold, but there is some oil residue present in the exhaust inlet of turbo. started engine, no signs of it losing oil through manifold (ran till warm), but it is leaking out the exhaust side of the turbo. oil feed and drain angles are sub optimal whilst sitting off to the side, but it isnt so bad that it wouldnt drain.

I know the turbo seal has a tiny gap in it and it should be spinning, but i would imagine it shouldnt be leaking through it assuming the chra is draining properly?

my guess is the turbo chra is trashed?

 

That's where I would start focusing attention on.

ks

 

my buddy gave me another t25 he had laying around, however, my build does not use the same wheels or housings. are all t25 chra's more or less the same?

 

Measure it and see. Cheap set of calipers will give you all the info.

 

if all the hook ups are the same I would swap it out, but I wouldn't go driving it hard unless its the same turbo, but you can at least see if it leaks at lower rpms, then you'd know if it was your turbo thats the problem.

 

so, update, looking for opinions on this:

i picked up a china CXRACING special from a buddy. cheap, new etc. I had to swap the compressor housing as im using a dsm eclipse housing, and a regular turbo housing will not work. the cxracing compressor wheel was too small, so I swapped over my wheel. However, after tightening it, the turbo was bound up.

upon further inspection, the snap ring that holds the bearing plate in behind the compressor wheel was not in its groove, nor did it want to go in. I didnt want to mess with it, so I ended up taking the shaft, a good spare t25 center housing and put another turbo back together.

seeing as the exhaust was coated in oil, i took the garden hose and a bunch of dawn dish soap and poured it into the exhaust, letting the water flow for several minutes. while it did help a little, i dont think it really did a whole bunch.

regardless, I put the t25 back on the car, and it didnt immediately make a smoke screen at idle. it was smoking, though i am guessing its from residue in the exhaust.

while driving, the exhaust is fairly clear, and the engine runs fine up to ~8psi, however when I give it full throttle (~13psi) it will occasionally misfire, and when it does, it coughs up a thick cloud of smoke, before clearing up again.

I checked the plugs, all were nice and clean. after the engine cooled, i unhooked the vband at the turbo, and didnt see any signs of oil. while I still need to check the IC, my BOV is mounted to the side of it, and would spray oil out when I had the other bad turbo on. With this turbo, everything is nice and clean. I should check the insides, but all signs show its clean.

so, my question here is, what do you think is causing the heavy smoke while under max boost? do you think the pulse from the misfire is somehow picking up oil in the exhaust? do you think there is still an issue with the turbo? maybe engine issues?

(the misfire may be from a damaged injector -- same day as the turbo failed, i had an injector driver in my ecu fail, causing it to stick wide open. the injector resistance did go up by a tiny hair but is still within spec, though i may change it out just in case.)

 

You have oil in your IC

 

ill take a look. its interesting the BOV isnt blowing it out since its literally mounted on the ic

 

After everything you did you need to first verify oil vapor in your cold side is not burning in the combustion, allow time for oil residue to burn off, then after that worry about other potentials like your turbo still has a problem, you have too high crankcase pressure, you have too much oil/pressure entering your turbo, your blowing out your spark.

 

thats why im concerned. everything was fine till the turbo went and the injector driver shorted. im hoping my crankcase pressure isnt spiking under boost. too much oil into the turbo shouldnt be an issue unless somehow my pump suddenly decided it can output more pressure. im hoping the misfire is just from oil, but i dont know.

 

You have to not know to have the adventure. Good luck.

 

thats why im here. im tired of the unknown.

 

Of course but there’s always more to not know.

 

I recently had my turbo flood my cold and hot side pipes with oil, water and dawn aren't going to get rid of it unless you scrub it out with a brush or something, I used a lot of brake cleaner to spray out the residue, which in some areas were puddles, so you defiantly want to get rid of any oil in the pipes before you drive around to much, it'll get pushed into all the new turbo parts and then you'll need to clean that as well. I didn't realize how bad mine was until I had the cold side disconnected and ran the engine up in RPM and it spit oil out into the engine bay, so I tore everything apart and cleaned it all up.

 

I have maybe 1.5ft of IC piping, so there isnt much to check.

Pulled the IC, it had a few cc's of oil on the inlet side of the IC, but none on the outlet side. all pipework was more or less dry. there was a very very slight film on the short section of metal IC pipes, but nothing crazy. intake definitely has a small coating of oil on the inside, but again, no standing oil.

took it for a rip around the block again. misfire is still present, and it does still smoke, but it seems like the quantity of smoke is becoming less. hopefully its just standing oil in the exhaust somewhere.

as for the misfire, seeing as everything was fine until the injector driver and turbo failed, any ideas on what to check?