Valve Stem Seals Or Turbo? Help A Canadian

[Paradis v.1]

Alright, i've been wrestling with this for some time.

I can't seem to get the answers locally. So I'm hoping the elite of A-U could take a gander and weigh in on this.

I'll try and be as specific and straight to the point.

Symptoms...

-Getting heavy short burst of blue smoke (clearly oil) out of my exhaust. This happens primarily after start up (but not only) and almost exclusively upon decel/idle at lights and such when i have to slow down after driving.

Comes and goes, but is much more prevalent during the first 5 mins of driving. I would say "cold", but there's many times where the car has sat for 15 mins (obviously engine isn't cold yet) and sure as the sun coming up i get those heavy bursts in the first few minutes.

-While i do suspect that i am burning a little bit of oil now at idle all the time now, i can say with 100% confidence that it does not increase nor do i get any blue smoke or burst when i'm accelerating or boosting.

-Turbo is series 2 (neo) rb25 turbo high flowed by you guys down under. there is some shaft play there, but there turbo as been pretty strong and hasn't shown the usual signs of dying on me yet.

-similar issue happened on my previous motor. makes me weary that its something beyond valve seals. This is different motor, but everything around it (turbo,plenum etc) is all from previous set up.

What i can rule out....

-compression and leak down tests. done and all is good.

-rear seal on turbo. pulled off the back side of everything and it looks good.

-ic piping and such doesn't show that oil has been circulating around in there. this i have to do again to be sure though as there was some other unrelated events that did track some oil in there so that made a little tuff to be positive.

So i'm really stumped. Given that this is kind of in a way a reoccuring issue with using the same turbo, kinda points to somewhere my turbo is pushing oil, maybe the front seal is worse than i thought.

But the timing of smoke with regards to sitting at lights, and being that its heavy at first makes me think seals... but after the engine is hot? 10 mins is clearly no where near long enough to have it get cold. and to have seals go on 2 motors... ? seems like more than bad luck. this issue was present pretty much right as soon as i got the other motor dropped in. So either it was happening to whomever had the motor before hand (no contact with said person) or there's some else at play..

Answers? Ideas that i haven't thought of? I've read alot of your puffing blue smoke threads, but they always end before the poster ever discloses what actually ended up happening.

[Paradis v.1]

ugh, c'mon you guys. i could really use some feedback. This issue has been going to for too long, you're my last line of defense

[SteveL]

-Getting heavy short burst of blue smoke (clearly oil) out of my exhaust. This happens primarily after start up (but not only) and almost exclusively upon decel/idle at lights and such when i have to slow down after driving.

These symptoms are typical of valve guide seal failure - oil seeping past worn seals when engine is left unstarted for awhile + oil being sucked past worn seals when inlet system is under high vacuum (throttle closed @ idle or under deceleration conditions). The situation apparently improving with increased engine running time may simply be due to expansion of metallic components changing running clearances.

One of the 'old ways' to 'fix' an oil burner was to try a higher viscosity oil. I had some success reducing oil burning on big 6's and V8's using Penrite HPR50, but i wouldn't recommend you try that with your engine. However you guys in the US and Canada tend to run quite thin oils, so trying a higher viscosity oil might be worth a try. That said, even if using a different oil helps with your problem it is, at best, a stop gap measure and you really should be looking at replacing the valve guide seals.

[Paradis v.1]

These symptoms are typical of valve guide seal failure - oil seeping past worn seals when engine is left unstarted for awhile + oil being sucked past worn seals when inlet system is under high vacuum (throttle closed @ idle or under deceleration conditions). The situation apparently improving with increased engine running time may simply be due to expansion of metallic components changing running clearances.

Ya, this is what I was convinced was the issue. I guess having two motors in a row with the same valve seal issue has made me very suspicious. problem is the timing and symptoms of the oil burning appear so closely to that of worn valve seals

I am using 0w30, but i'm going to replace in about a week or two. thankfully I have access to a performance and a couple mechanics on the weekend that i don't have to pay for, as it's a time consuming job.

...still i really did want to do this unless i was absolutely sure.

[Paradis v.1]

someone brought a good point. I guess i could be more specific on my set up..

its an RB20DET, but everything else around has been upgraded/modified (EMS,Fuel,IC etc) and am running about 1.25 bar (18psi) producing about 298rwhp

[Paradis v.1]

has anyone by chance ever had a situation of their oil return line being kinked up? what are the symptoms of that?

[SteveL]

Since the problem is mostly occurring with inlet manifold under vac conditions, this suggests the problem is not turbo related. Factory oil returns are cast into the head/block so there is no return line as such unless something something extra has been added by yourself or others. I really doubt this is your problem, as valve seals in good condition should be able to cope. Moreover, you should see oil smoke throughout the rev range (more-or-less) if the head was being 'flooded' with oil.

Two engines with the same problem is bad luck, but quite possible. These cars/engines can sit around for quite awhile in Japan leading to hardened/failed valve seals (and other rubber components).

One possibility - have you checked the PCV system is operating correctly ?? Sometimes a clogged/blocked PCV can result in a pressurised block/head leading to leaking seals, etc, although usually the oil dipstick will start popping out before any sort of major seal failure occurs.

[gotRICE?]

I think i have a very similar problem. So not hi-jacking, just adding

This morning when i started the car up after only been sitting overnight, i went out as usual.

Engine still "cold" as in only traveled approx 700m (3-4 sets of lights). At one set i noticed a rather large cloud pass me. Thought.. bah dirty f**ker in the car behind me.

2nd set of lights i take off as you normally do when its cold, and happened to look in my mirror to see a cloud puff out of my exhaust. ( I think it was mine)

Was straight onto open road driving, never saw another puff. Did some heavy deceleration in multiple gears, and some hard revving on the spot with a mate watching. Nothing at all. Then some very heavy boosting with him watching also. Nader.

Have yet to try it again from cold, and take off any piping to check for oil. But i will, and will report back on my findings too for reference.

Mine is a 98 R33, 62,000km running 10psi via R32 actuator. (usual mods, fmic/3" turbo back)

My PCV and breathers are routed to a catch can, atmo vented.

I have my fingers crossed its the turbo. Id rather replace that than do the valve stems? Or am i over estimating the cost of doing so?

[Jet 20]

I am using 0w30,

0w 30 seems very very light weight to me, im running an rb20det also and im using a 20w 40 penrite oil in mine.

the motor has done 95,000 km and has no oil smoke problems at all.

that oil weight i believe is more for brand new engines, not 20 year old engines.

[Paradis v.1]

Since the problem is mostly occurring with inlet manifold under vac conditions, this suggests the problem is not turbo related. Factory oil returns are cast into the head/block so there is no return line as such unless something something extra has been added by yourself or others. I really doubt this is your problem, as valve seals in good condition should be able to cope. Moreover, you should see oil smoke throughout the rev range (more-or-less) if the head was being 'flooded' with oil.

Two engines with the same problem is bad luck, but quite possible. These cars/engines can sit around for quite awhile in Japan leading to hardened/failed valve seals (and other rubber components).

One possibility - have you checked the PCV system is operating correctly ?? Sometimes a clogged/blocked PCV can result in a pressurised block/head leading to leaking seals, etc, although usually the oil dipstick will start popping out before any sort of major seal failure occurs.

Well I'll have another quick gander this afternoon at my PCV vavle and the front side of my turbo while i'm at it. I know the timing of the oil being burnt is valve like (under vac) but there engine being cold has no bearing on the smoke showing up, and there's nothing at start up, which i thought you should see some if it is valve seals.

..Two engines with worn valves is bad luck, but it's almost uncanny to have a motor replicate the symptoms as soon as i swapped it in. I've learned that sometimes you can overanalyze the situation, looking for the most bizarre problems when they aren't there. I was convinced once that i was hydro-locking the engine after some work i did, when it turn my stinking red top battery just wasn't holding a big enough charge anymore.

Something about this just smells wrong, literally. Lol. I suddenly like my Hi-Flow turbo is acting a fool and i'm going to investigate

[Paradis v.1]

Since the problem is mostly occurring with inlet manifold under vac conditions, this suggests the problem is not turbo related. Factory oil returns are cast into the head/block so there is no return line as such unless something something extra has been added by yourself or others. I really doubt this is your problem, as valve seals in good condition should be able to cope. Moreover, you should see oil smoke throughout the rev range (more-or-less) if the head was being 'flooded' with oil.

Two engines with the same problem is bad luck, but quite possible. These cars/engines can sit around for quite awhile in Japan leading to hardened/failed valve seals (and other rubber components).

One possibility - have you checked the PCV system is operating correctly ?? Sometimes a clogged/blocked PCV can result in a pressurised block/head leading to leaking seals, etc, although usually the oil dipstick will start popping out before any sort of major seal failure occurs.

Well I'll have another quick gander this afternoon at my PCV vavle and the front side of my turbo while i'm at it. I know the timing of the oil being burnt is valve like (under vac) but there engine being cold has no bearing on the smoke showing up, and there's nothing at start up, which i thought you should see some if it is valve seals.

..Two engines with worn valves is bad luck, but it's almost uncanny to have a motor replicate the symptoms as soon as i swapped it in. I've learned that sometimes you can overanalyze the situation, looking for the most bizarre problems when they aren't there. I was convinced once that i was hydro-locking the engine after some work i did, when it turn my stinking red top battery just wasn't holding a big enough charge anymore.

Something about this just smells wrong, literally. Lol. I suddenly like my Hi-Flow turbo is acting a fool and i'm going to investigate

[Paradis v.1]

well not that it really means anything, but i had my pcv blocked off and it was venting only into my air inlet after the maf, so i just put it out to ATM for the sake of curiousity and i didn't see any more puffing.. bizarre. it shouldn't matter as i'm not seeing smoke on boost, but i still don't think it cleared it up. i just think my car was being nice to me today. the puffing will back i'm sure and i'm ready to declare valve seals at this point

[gotRICE?]

well not that it really means anything, but i had my pcv blocked off and it was venting only into my air inlet after the maf, so i just put it out to ATM for the sake of curiousity and i didn't see any more puffing.. bizarre. it shouldn't matter as i'm not seeing smoke on boost, but i still don't think it cleared it up. i just think my car was being nice to me today. the puffing will back i'm sure and i'm ready to declare valve seals at this point

I would appreciate it if you did report back

And i will do the same. I might go down and start the car up tonight and see if it will smoke again too.

[ZILR-34]

could be presure blow back or rings are on the way out

[Paradis v.1]

could be presure blow back or rings are on the way out

pressure blow back? like how? Rings aren't the issue, my leakdown and compression tests were strong and clear so i'm going to assume thats not the issue

[Paradis v.1]

so I finally went for a good rip again tonight (been crappy outside the last 2 days) and thats now 3 times in a row driving with no oil puffing after changed my vent so that it wasn't going directly into my inlet anymore. (my pcv has been blocked off for some time). So i'm a little stunned as to how that's eliminated the problem... I'm still holding my breath. I think when it warms up in a couple days i'll see dfferent results.

chilly chilly out tonight. i was boosting 20 psi, woohoo,

Edited April 15, 2009 by Paradis v.1

[gotRICE?]

Went and had a play with mine tonight.

From cold. Let it idle a little. a few blips of the accelerator. Nothing. All good.

Went for a little drive (car still cold, but needle just starting to move). Stopped at some lights and gave it a blip. Cloud. Eep.

Pulled over, did it some more, cloud cloud cloud.

When you blip the throttle, it will shoot out smoke, then as it idles down, it will billow out for a few seconds then stop.

Didnt appear to do it once the car had warmed up tho. But by this time i was pissed off and stopped looking

Same as yours? Worse? Less?

[SECURITY]

as i was reading your first post i was thinking PCV for sure.

PCV would have definitely caused the symptoms you're describing - i was in the same boat at one stage.

what happens if you let the PCV vent into anything other than the head then it doesnt see the changes in pressure for it to work - the valve is always open and the oil in the sump goes into your head/intake.

keep the PCV running in the standard setup and you'll be sweet.

[Paradis v.1]

as i was reading your first post i was thinking PCV for sure.

PCV would have definitely caused the symptoms you're describing - i was in the same boat at one stage.

what happens if you let the PCV vent into anything other than the head then it doesnt see the changes in pressure for it to work - the valve is always open and the oil in the sump goes into your head/intake.

keep the PCV running in the standard setup and you'll be sweet.

Wait a minute, i'm not quite getting it, the changes in pressure part that is. The stock set up has the PCV working at idle and vac, but the by pass inlet route is there for when you're under boost. Now plenty of ppl go to catch cans and elminate the PCV altogether. But the turbo inlet route is still present in some set ups.

^^^^ Now, i don't have a stock plenum anymore, i've been running a custom side feed for sometime, and the PCV has been eliminated from the system a long time ago (about as long as i've had this issue oddly enough) but the venting has always been kept to the inlet. Now, under boost, there's no difference right? as it would be going that way anyways... However under idle its being sent through there as opposed to the PCV. I don't understand how going through the PCV would eliminate oil showing up in my exhaust. there's no device or trick in the PCV that would collect the oil that i've been seeing.

To summarize, I'm not getting how the PCV is changing the content of the air. Ya sure pressure, boost, vac strength etc etc. But essentially the content of the air (oil, gas, whatever) isn't being altered by going through your inlet or your PCV right? It still ends up being burnt off.

Went and had a play with mine tonight.

From cold. Let it idle a little. a few blips of the accelerator. Nothing. All good.

Went for a little drive (car still cold, but needle just starting to move). Stopped at some lights and gave it a blip. Cloud. Eep.

Pulled over, did it some more, cloud cloud cloud.

When you blip the throttle, it will shoot out smoke, then as it idles down, it will billow out for a few seconds then stop.

Didnt appear to do it once the car had warmed up tho. But by this time i was pissed off and stopped looking

Same as yours? Worse? Less?

I don't know if this is like my issue, could be something more serious if your smoke is that closely linked to your throttle. Mine had nothing to do with boost or throttle, just went i was under 0psi or under vac is when i would see it.

Is there blue smoke when you start up, or do you have to start driving?

Take off your hot pipe and your inlet and see if there's alot of oil there. If you can manager it, take off your down pipe and have a look at the back of your turbo.

Do a quick compression test and see where you're at. If you smoking issue are related to you're throttle, as in when you step into it you see smoke, then could be your turbo. or engine.

If you think it's valve seals then from what i gather, its related to burning off primarily in the first few mins of driving, and a hot engine will have parts expand and the seal will be better than when it's cold. A test someone told me about was to get up to a high speed in a high (like highway speeds) let off the throttle and let it wind down, then give step into it and watch for a poof out of our mirror.

If you want to know if it's your PCV just out of curiosity, block off the hose going to your PCV, and block off your inlet hose on the other end. Vent your valve covers to ATM just as a test and see if you're still seeing it.

[Paradis v.1]

hah... and as i finish typing that and drive to the store, i'm greeted by my little blue friend. it wasn't for more than a second or so and it was small but thats exactly why i said i'm still holding my breath. I'll be convinced when i have a +week of clean exhaust.