Intermittent high oil consumption/smoking.
Looking for suggestions as to possible causes of intermittent high oil consumption and smoking.
One thing is certain, the oil is being burned as evidenced by the smoke from the exhaust, and this smoke when visible is visible primarily at idle or directly on pulling away from a standstill after the engine has been idling for a minute or two, for example at a traffic light - the reason I'm pointing this out is that even though it might be burning oil with the car in motion, there is no heavy smoking to indicate this, it might be the same amount of smoke as with the engine at idle, but less noticeable due to the increased volume of exhaust gasses.
My initial thought was valve seals, but that has been shot down by a master mechanic and engine builder friend who feels the amount of oil being burned is too great to be leaking past the seals - we're talking perhaps as much as a liter of oil in 1000km or maybe a little less.
I don't think it's the rings because of two reasons - 1) there is no noticeable smoke at high rpms and 2) the lack of consistency - I can drive for a week (200~250 kms) and the level on the dipstick drops 3mm, and next day it drops another 3mm over a distance of 50~60kms - to my way of thinking with worn rings, the oil consumption will correlate a little more closely with distance driven, and increase with higher engine speeds.
Also probably significant is the fact that it does not consistently smoke at idle, some days there will be no visible smoke, and other days, it's a continuous stream of smoke gently puffing from the tail pipe.
It's as if there is some sort of an opening or valve allowing oil fumes to be drawn into the intake and burned, and one day it's there and another day it's not or it's open one day and closed the next.
The PCV valve was my first suspect - that has been eliminated in two ways - 1) it has been replaced and 2) I've disconnect it and capped the hose with my finger whilst the engine is smoking at idle - with no decrease in the amount of smoke.
oil consumption.
Fordem, I was just thinking, did this oil consumption started after you have done the engine flush ? The internal "cleaning" can, on the older engine, clean behind the oil control ring, and remove the deposit between the oil control ring and the piston (in the groove of the piston) Once this deposit is gone, the ring sit better in the groove and doesn't press on the cylinder as hard as it was before the "cleaning" ...increasing the oil consumption.
You could try to use use a heavier grade of engine oil...that could help....
Just an idea...
Happy io
No - it was there before
As you may recall, I bought my iO with a number of issues, high & erratic oil & consumption were among those, although the results of the engine flush initially were quite promising, in the long term (and that includes a second flush) it does not seem to have done much, the lifter rattle is still there and just as erratic.
Switching to the 15w40 oil did reduce consumption,but what puzzles me is why it changes - I can drive for several weeks without having to add oil (no or very little change in level), and then, the next week, I'll need to top it up twice.
valves seals
I would replace the valves seals. I never done it on this car, but on some you can do it without removing the head, bringing the cost of the work a lot cheaper. This should, at the very least, be part of the problem.
The leak at the valves seals can be related to how the car is driven, more change of gear, change of rev, engine temperature. What I think is that if you do a long drive of 200km, non stop, at stable speed/rev, you might use a lot less oil that going to the shop, 10 time, every morning (cold start), driving in town for 20km at different speed, changing gear all the time. While this is an extreme example, more subtle difference will still impact on the oil consumption.
The valves seals are on the top of the valve. These seals are sensitive to the temperature. Once the intake valve is open, the piston does a high suction (variable with the rev, and acceleration), that could bring oil in the cylinder, the higher the suction......
Depending of the cost of replacing the valves seals, it could be a good idea.
As often...I could be wrong
Happy io
crank case ventilation
check the ventilation circuit - I've had situations where at idle the increased vaccume and a faulty rocker cover vent valve caused oil to be sucked into the inlet.
Not sure on the GDI where this occurs, on the MPI it enters upstream of the throttle body into the main inlet.
otherwise high vaccume events would suck oil past the valve stems - but this is gradual and not a sudden thing UNLESS you've had a chronic failure - a compression test will show straight away the faulty cylindr however I doubt this very much.
Crankcase ventilation was the first thing I checked.
Keep those ideas coming - your's may be the one that slipped my mind.
The GDI engined iOs have a fairly common crankcase ventilation system design, which I suspect will be very similar to that of the MPI engined version, whatever differences exist will be due to physical layout, it's used on most EFI systems.
There are two connections between the crankcase and the intake, one upstream from the throttle body (between the throttle body and the MAF - this is the one Bob has identified) and one downstream - the upstream one is actually an intake, and the downstream one, which is the one with the PCV valve in it, is where the crankcase fumes are drawn into the engine.
With the throttle closed, there should be no appreciable vacuum upstream of the throttle body - in fact - theoretically speaking, there should be no appreciable vacuum upstream of the throttle body at any time as the only obstruction to free air flow should be the air filter.
Depending on throttle position there will be vacuum in the intake downstream from the throttle body and this will be highest with the engine at idle, at which time the PCV valve should close to prevent oil vapour from being drawn into the intake, as the throttle opens, the vacuum drops and the PCV valve should open allowing the crankcase fumes to be drawn into the intake and thence the engine where they will be burned - the idea here is to have a controlled mix of fuel/air and crankcase fumes - too much crankcase fumes at idle and not enough air/fuel and the engine will die. The system also ensures that there is maximum flow of crankcase fumes at larger throttle openings which coincides with maximum engine load when most any blowby will be highest.
The upstream connection allow fresh air to be drawn into the crankcase to replace the air being drawn through the PCV valve, on non EFI vehicles, it's usually routed to the air filter housing to ensure only filtered air is drawn in, but on EFI it's located after the MAF to ensure that all air passing through the engine is metered.
A defective PCV valve was my #1 suspect so that was replaced and the entire system checked - the hoses are all free from obstruction, and there is no trace of oil deposits in any of the intake ducts or plenums.
Edit.
You know Bob, you've got me thinking - if I'm right - the throttle on a GDI engine does not work the way it does on a conventional engine. It's "drive-by-wire" rather than a cable from the throttle pedal and I believe controlled by the ECU - I suspect that when the engine is in a lean burn mode, the throttle plate may be wide open and the engine's power output controlled by how much fuel is being injected - in pretty much the same way as a diesel operates.
There would be very little vacuum which would then affect how the PCV system functions - BUT - I did disconnect the PCV valve during one of the "smoking at idle" episodes so I know that's not where the oil was getting to the chamber.
Ehhh - this is a mistery to me.
oil
check the ventilation circuit - I've had situations where at idle the increased vaccume and a faulty rocker cover vent valve caused oil to be sucked into the inlet.
Not sure on the GDI where this occurs, on the MPI it enters upstream of the throttle body into the main inlet.
otherwise high vaccume events would suck oil past the valve stems - but this is gradual and not a sudden thing UNLESS you've had a chronic failure - a compression test will show straight away the faulty cylindr however I doubt this very much.
Would a compression test give you information about the valves seals ?
I thought that the oil cumulated just after the valve seal during idling...at 7/800rpm then get sucked, washed in the cylinder at the first higher rev, ....then giving smoke. The main reason that seals gets faulty is...age...but mainly heat, I have seen some nearly missing or crumble at first contact. The "gradual" should be the same as the change of rpm.
I am still 100% agree that a compression test (dry and yet) will give you some valuable info.
Considering the amount of oil used....I thought that if it would be because of a faulty vacuum, one would see a fair amount of oil in the hoses...
I haven't worked in that field for a very long time, and I am just giving idea.....I could be very....you know:)
Happy io....
Nope - leaking valve seals won't show up in a compression test.
at least - not directly - if the compression tests show the rings as good (high "in spec" numbers for dry test), it is normal to assume that the oil is nor entering the chamber past the rings, and so must be the valve seals - but - this is not always a valid assumption, because the compression rings are not responsible for oil control. In discussions with a local guru whose opinion I trust, I was told it's possible for the oil control rings to be completely gone and the engine still have good compression - this is the same guy who has suggested that the volume of oil being burned is too great to be leaking valve seals.
I have not gotten around to doing a compression test - probably because the engine runs so well it's hard for me to believe the compression is low - there is no lack of power, I can break the back tires loose at will, which is not the easiest of things to do with most automatic transmission vehicles.
agree
You wrote
I was told it's possible for the oil control rings to be completely gone and the engine still have good compression - this is the same guy who has suggested that the volume of oil being burned is too great to be leaking valve seals.
Agree with both statement. This said, it would be almost impossible to say that this much is because of the ring and this much because of the valve seals.
I think that you have done and search for other easier, to fix that is, possibility of why the oil is going...even if not 100% sure of why it is not always the same quantity :) What your "local guru" think about the erratic oil consumption ?
I suggested to replace the valve seals, because it can be cheap to do. If it cannot be done cheaply, I wouldn't bother. It has to be cheap to be worth trying. It is a risky gamble, the bet have to be small :) You don't want to pull the head out, put it back, then removing it again to rebuilt the engine (if needed to do the ring)
Happy io
I'd have to invest in a valve spring compressor.
I've considered changing the valve seals, but, the design of the GDI DOHC engine is such that I'd have to invest in a valve spring compressor or pull the head, neither of which I'm particularly keen on doing - I'm thinking if I have to open the engine, just rebuild it and get it over with - for now, it runs well (apart from the oil consumption) and I'm not inclined to go, as we say here, looking for trouble, so I'll probably just continue to top it up when necessary and use it as a spare vehicle.
I found this video
I found this video, that is how I used to do it. You can hold the valves in places with a modified spark plug and an air compressor. The advantage of the rope is that it won't stop working in the middle of doing the work....It can be "funny" to have the compressor stopping, and see the valve falling in :)
This repair should make the smoke after an idling period disappear, but the chances of being the main oil consumption problem is slim. You will have to make a tool just for that purpose. In his case, the smoke remained, but it only cost him an afternoon and limited parts....not much $$$
Keep it as it is, is an understandable solution !!
That's a much simpler 8v SOHC engine.
That's a much simpler 8v SOHC Suzuki engine, probably a 1.6 in a Vitara.
The GDI requires quite a bit more teardown just to get to the valves - not only because it's DOHC, but also because it's GDI - the entire intake system has to come off, because it sits over the head, the manifold actually bolts to the top of the head.
.
I tried to find one with the gdi's io engine, but no luck...
.I liked this one, because it is a ...Suzuki, and the fact that it didn't work, and when I saw the smoke coming out of his exhaust at the end, I laugh for 5 min. In one of his post, he said that he sold the S@#& That may have been a bit too much smoke for faulty valve seals....Again, it didn't cost him much to try.
Seriously, that was for the principal ....
Happy io
I made an interesting observation today.
Yesterday was a holiday and I took the opportunity to do some remedial work on the iO - it involved disconnecting the battery so one of the tasks that had to be done afterwards was a recalibration of the ECU, a process which involves allowing the engine to first warm up, and then idle for three x 10 minute periods, the last two with the a/c on and all the windows open.
I've done this recalibration on a number of occasions and have noted that I will get a fair bit of smoke out of the exhaust during the process - I always assumed it was oil smoke - today however - I just happened to check the oil level before starting the engine, and I also checked it after and was quite surprised to see there was no change, the smoke also did not smell like engine oil or excessively rich,
smoke
I won't start talking about smoke colour or even smell.... but I think that if you were to find a difference on the dipstick after 10 min of idling, you would have BIG problem. I don't think that 10 min of idling would burn enough oil to be visible on the dipstick. This is just my thought, and I might be wrong.
Happy io
Let me put it this way Claude
You haven't seen this thing smoke, I have, and take it from me, that much smoke in 30 minutes, does show on the dipstick - I don't know if you recall, the oil consumption was worse than it is now, I've seen this car go through a liter of oil in a day, no more than 40 kilometers or so.
The subject of this thread defines exactly what puzzles me - the problem is intermittent - one day it's smoking like a chimney and burning oil, the next day it's not.
If it was burning oil consistently, I'd be able to figure out my next move, tear down & rebuild, replace the engine, get rid of it - but I'm unwilling to spend money, unless I know why I'm spending it.
Oh - I know you didn't ask, but the smoke was light & gray, almost white - not the blue that you get when an engine burns oil, nor the black soot of an overly rich mixture.
whoa
I forgot that it was...that much...1 liter for 40 km.... :(
I still have a few...old...contact, I will contact them to try to find "fresh" idea...
Just to check...if you pull the dipstick out while the engine is running, do you have air coming out of where the dipstick goes ?
Happy io
The lack of consistency is what freaks me out.
I have to check the oil every couple of days, and check does not mean top up - most of the time I don't even pull the dipstick all the way out of the tube - pop the hood, pull the stick far enough to see the level, put it back and close the hood - I can go two maybe three weeks without seeing a drop in the level and on the next check a day or two later - I'll have to add half a liter.
That liter in 40 kms was a one off occurence and happened before I switched to the 15w40 all fleet oil (CF/SM) I'm using now, I think I was running a 10w40 SN back then, so this oil in theory is slightly thicker in cold weather, but, temps here are never below 70*F, so I don't think that makes a difference.
Intermittent high oil consumption
Hi , I'm doing some research on the io . I like to buy one and transform it to a offroad rally car.
Coming back on your post about the high oil consumption, did you solve the problem?
Before I read this post, a car dealer in my country told me that it is well known that the io has oil leaks and high oil consumption/ smoke problems (all are import domestic Japanese cars).
Please advice
Thx
John4x4
Just my opinion...
You're discussing used Japanese imports with a car dealer who says xxx make/model all have oil leaks & high oil consumption - find another dealer - he's either trash talking a product because he doesn't have one to sell you, or, he's setting up to not offer a warranty on the one he's about to show you.
Let me make it clear I've never owned a new iO, and in my opinion commenting on the reliability of a used vehicle with an unknown history is likely to be far off the mark - we've had multiple new Mitsubishis (my wife currently drives a 2012 Lancer) and they have been neither leaked nor burned oil - we've also had a Mitsubishi engined Hyundai from new and that was problem free until severely overheated.
I bought my iO used, and was told by the seller before purchase that it had problems - it was a give-away price and at the time I needed a vehicle, so I took the chance - I've owned it for a little over two years, spent more than I paid for it in parts & repairs, none of the problems was anything major, the bulk of the money went in new springs & shocks/struts and I have no regrets about the purchase - yes - it was that good a deal, if I sold it now I could/would probably make a handsome profit.
Back to oil consumption - it burns some oil - at this point I have no idea how much, a lot of the oil it was using turned out to be a leaking cam cover gasket, which I only figured out & fixed recently, so I haven't been able to get a good idea on the oil consumption - but it's very easy to see that it is way less than before.
oil losses
Back to oil consumption - it burns some oil - at this point I have no idea how much, a lot of the oil it was using turned out to be a leaking cam cover gasket, which I only figured out & fixed recently, so I haven't been able to get a good idea on the oil consumption - but it's very easy to see that it is way less than before.
I used to loose oil, more so since I switched to 10/40 synthetic (matches my wife's 307 peugeot) . I din't loose as much as you do but when I did loose some it was as follows:
towing a trailer,
high RPM (very fast freeway)
turned out that the bulk of the oil was leaking out of the cam cover and going back down the breather as my oil return holes in the block were slightly fouled - cleaned them with a wire and replaced the cam cover and presto - no oil loss
Syndicate
oil consumption
You may have more than one problem. I am assuming that you don't have oil leak...
I would tend to say that, as you thought, the valve seals are gone, and while it may not be sufficient to fully explain the heavy oil consumption, it does explain the smoke after an idling period.
You probably have the ring gone too, distances is not always in relation to the amount of oil burned. Plenty of other factors such engine temperature have a direct inpact, or how hard the engine work like going up hill, or down hill, or even driving in town or on the long distances.
Happy io.
My io is now SOLD Thankshttp://pajerio.com/forum/claudes-io-2002-zr-built-thread-onlyhappy-io