View Full Version : blue smoke, sometimes, at idle - turbo seals?

06-13-2006, 06:59 PM
ok, so here's the deal:

this is an '89 b230f, with turbo/intercooler, and a whole bunch of other stuff, i can't think of it now - but the point is, i just put a new head/cam on it (***i cut grooves in the cylinder head, i'll post pics and some results on the somender singh thread soon).

i was getting smoke before, but that was (at least) due to the old head gasket, also the turbo sat around on a bench for a while, got dried out maybe?

anyhow, i get blue smoke - sometimes.
i'll be tear-azzing around and everything will be going great and then at a stop light it will star billowing blue smoke.

so i bugged out today, thinking that all the work i did was for nothing, and i pulled the plugs and checked the compression (yes, i did the compression test correctly, no plugs and throttle body wide open).
i got 200-205 psi in each cylinder.
also, the plugs were perfectly clean and dry.
so i think that the oil is coming post-combustion.

that said, assuming this is correct, how do i go about replacing the seals on the turbo, and is it even worth it, or should i try to find one for sale?

embarrassed to mention it, but i think this is a 13c turbo? the valve that dumps to the intake side when the throttle body is closed is at a funny sort-of slant, i believe that the turbo originally came from a '90 740t.

anyhow, where should i go to purchase these seals?
and is there anybody that can give me an idea of how much time i need to take the car off of the road for, can i do this in a couple of hours?

any help/advice is greatly appreciated, and anybody with a quick bolt-on replacement that will not smoke that they care to get rid of?


ok, so in an attempt to be sure that i have correctly identified this turbo i used the search button and found a link to this site:
i do see what appears to be my turbo, refered to as a "later version ... td04", so now i really have no idea, 13g maybe?
it was blowing ~6 psi before i installed the mbc, another noticable difference that may help to identify this turbo is the actuator arm, it is not threaded - i assume this means it is not adjustable.

06-13-2006, 07:21 PM
Not that I would think it would cause THAT much smoke: but did you replace the valve seals when you had the head out?

06-13-2006, 07:25 PM
Not that I would think it would cause THAT much smoke: but did you replace the valve seals when you had the head out?

nope, but i got a reasonably new head from a friend, he had had it rebuilt recently and driven it for only a short time.

i have no idea of the history of the turbo.

06-13-2006, 07:31 PM
It sounds to me like youve got bad valve seals or worn guides

06-13-2006, 07:36 PM
i think that the head is fine, it has been rebuilt within 1000 miles. this may be wrong but firstly i would like to focus on the turbine seal, in fact any seal that could dump oil into the exhaust post-engine.

any idea of where i get the parts to overhaul, and how i will be certain that i am purchasing the correct set of seals?

06-13-2006, 07:51 PM
How long did the head sit unused? I have heard that will kill valve seals (although I have never understood why). Either way, I would be suprised if a valve seal would cause it to "[billow] blue smoke"

06-13-2006, 09:12 PM
It's a turbo "major" seal.

Ben's black 740 does this occasionally. Usually after being driven hard. Almost always coming up to a light and sucking a lot of vacuum on decel.

Valve stem seals either smoke on startup or all of the time. Not just sometimes.

06-13-2006, 10:31 PM
Pull off the air intake hose to the throttle body........
If it has oil dripping out of it you have an issue with crankcase vapors or a turbo.
Isolate this by removing the crankcase vapor hose from the intake hose by the turbo, plugging the hole to the intake hose and drive like a savage......... Lots of oil+crankcase vapors coming out of the hose and suddenly it does not do the smoke routine? You will 'get' to 'freshen' the lower end. Still does the same smoke routine while not being fed crankcase vapors your turbo is adding to the mix.......
If the throttle body and air intake hose to it has very little oil in it you could be having issues with valve stem seals or oil rings.
I do not see redblocks do this often, but back in the day if we did a head on a high miles Honda without doing rings you could count on it burning oil after doing the head.
I have seen worn valve guides make for excessive crankcase vapors (no sh*t!!). That motor had valve noise as though it was a B-20 in need of a valve adjustment.

06-13-2006, 11:01 PM
so i bugged out today, thinking that all the work i did was for nothing, and i pulled the plugs and checked the compression (yes, i did the compression test correctly, no plugs and throttle body wide open).
i got 200-205 psi in each cylinder.
also, the plugs were perfectly clean and dry.
so i think that the oil is coming post-combustion.

how many miles on the block?

did you do a dry/wet comp test?

did you remove and inspect the O2 sensor?

From what you describe, it does sound like your turbo is letting oil out past a seal; and likely on the turbine side.

Clean spark plugs...as in no soot or oily coating...indicate no probs from the intake valve stem seals.

Your comp test readings look good. Doing a wet test would help indicate ring sealing capabilities. A slight reading increase wet indicates rings good; a large reading increase wet says the rings are not so good.

Pull the O2 and look at it. I have seen them black, oily and sooty from a mitsu that decided to lubricate the exhaust system internally.

Checking the turbo shaft radial and axial play would also be a good idea.

If the O2 looks black, oily, and sooty, while the spark plugs look clean, the culprit is most likely the turbo.

...I think that your conclusion is correct.


06-14-2006, 01:04 AM
when this happened to the sub( silver740) it was the turbine shaft seal, i rebuilt a turbo for the 760(before mentioned black 740, 100k mile soon for sale) but have not put it on yet. It was very easy to see when i removed the turbo, you could see oil going from the shaft on the heat sheild, when i pulled the turbo apart there was a lot of cooked oil under the sheild. A turbine shaft seal is only 5$(15 for gapless), if there is little play just mark the wheels, pull it apart, clean everything, and reverse. Make sure you put the wheels back together alinged...this is all about a t3, i have yetto take apart a mitsu, you might want to rebalance a mitsu when you take it apart, turbos are very simole

Les, slight limp
06-14-2006, 04:58 AM
Make it do the smoke thing for a few minutes and then turn of and check the plugs, if they are clean it's not valve seals, i think your own theory is the correct one, good or bad i look forward to your impressions of the grooves, les.

06-14-2006, 06:42 AM
Oh man

I have the exact same problem, I guess it can't be the turbo because I have a brandnew one.
Eating my heart out wondering what to do cause I spent so much redoing that engine (B21ET = almost the same as B21FT).

No smokin' when driving, stop at a light and get smoked out by your own exhaust gasses.

New turbo, new head, same valves with new seals, new pistons... meakin' me mad

06-14-2006, 10:06 AM
wow, quite a few responses, thanks guys.

when i put the head on i also made and installed a catch-can, using an air compressor filter, i have kept the vacuum configuration as it was, with the vacuum nipple t-ed in to the intake side of the filter/bowl - it seems to be working well, catching oil and stuff. but i am getting a lot of crankcase pressure, the oil light goes on at start-up and i can feel the air escaping from the oil fill hole, this was a problem before i did the head as well.

i did not do a follow-up wet compression test, at the time i was thinking that these were good numbers, and so i let it go at that. i will do the comparison wet/dry on the weekend.

tonight i will pull off the exhaust manifold and take out the o2 sensor, i'm thinking that if i'm getting trouble from a valve it will have to be an exhaust valve, since the plugs are clean - i may be wrong though, if so, please tell me. i will observe whether or not there is any oily/sooty residue in any of the exhaust ports - hopefully in this way i can get a definite answer on the valve seals/guides.
i have no doubt that the o2 sensor will be dirty, since there definitely is smoke, but i can compare it with the exhaust manifold to get an idea of whether the oil comes from the turbo.

in any case, if it is the turbo, then where should i go to find the seals, or an "overhaul kit"?

or should i say forget it and go to the $50 all you can carry out day at the junk yard and grab a late 940 turbo? (this should be a mitsubishi, yes?)

oh, and les: i am at ~16 degrees advanced, with 10 psi on a formerly n/a motor (high compression), 37 lb/hr injectors, and i do not get any pinging at all. my guess is that i'm not in that danger of pinging zone yet anyways, but i intend to further increase the boost and so i'll see where it starts to ping - the grooves definitely don't appear to have hurt any. i am using a different cam (the stock turbo cam) so i expected some more power, but it pulls like mad now, well beyond my expectations - i'm quite pleased. i will post pictures of the grooves this weekend.

thanks all.


Les, slight limp
06-14-2006, 12:14 PM
This might be completely wrong but could it be a cbv/bov problem, decel for lights, compressor stall, oil can leak past the float bearings or thrust bearing, don't shoot it's just an idea.

06-14-2006, 12:52 PM
I had the same problem on my 760 Turbo. I rebuilt the head and still the same problem. Came to find out it was my turbo all along. It would only smoke at intersections and it would smoke bad.

Hank Scorpio
06-14-2006, 12:57 PM
Make sure your oil return path is completely unblocked and downhill for its entire path. A plugged oil return line will make the turbo smoke like an SOB.

06-15-2006, 10:40 AM
ok, just one more quick question, this is directed to anyone who has rebuilt one of these turbos, or even taken one apart for that matter.
when i removed the turbo, to change the head, i took the thing out whole, still attached to the exhaust manifold, my question is this: can i just take the turbo apart while the hot side is still mounted to the mani/engine?
are all moving parts and the seals that keep fluids and gasses separate enclosed in that front (cold) piece of the turbo?
i guess that anyone with a diagram or directions for rebuilding one of these td04s or something similar might be able to help me out, i just need to see how it is put together - i want to make this process as quick and painless as possible, and i'm thinking that i'll take a wild stab at a junkyard cold-side of one of these, just leave the hot side connected to the mani and pull off the front, swap it out and see if there is any change (assuming the seals on the junk yard part are ok).
is this how these things come apart, or is the turbine at the exhaust side somehow inserted into the hot-side housing such that the unit must be disassembled out of the vehicle (is it like the kid with a hand full of cookies, unable to get his hand, with the cookies (the turbine wheel) - out of the jar?).

thanks again.

06-15-2006, 11:45 AM
all of the seals are in the center, i think you can take the clamp off and pull the center and coldside off, the turbo will come off the late manifold very easy

06-15-2006, 11:59 AM
excellent, that's what i was hoping.
so i'm going to try to scavenge what can from the junkyard.

thank you for your help.

07-18-2006, 09:30 AM
Had my turbo checked at the local turbodealer, he said it was perfect!
I could see myself there was no sign of any oil leak, the oil return path is perfectly clean and i have a new crankcase vapor and it's not going back to the turbo hose.

Could it be that the pistons rings are not placed correct? I had it done at the local shop ( a professional engine shop)

Greetz Joris