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Driver side bank 2, similar story as far as plug condition. Best 5, worst 8 on that order
the oil on threads is really baffling me.
could it be possible to have multiple cylinders scored?
I can try different plugs, im open to that, what do you all suggest?
petza, i thought the 4 prong bosch are only for the V8 S (non turbo).
I swapped my old berus into bank 1, no change in how it drives
Ill pull intercooler bottom pipes to check for oil. I saw some in the drivers as usually, 1/2 teaspon maybe. Didn't check the bank 1 side however. Ive never cleaned them out.
ill recheck codes and fault counts after the coil swap. Im gonna put the old ones back on b2, but yeah, these aren't the problem, its just drowing on oil for some reason, and it all started with the switch to the 0w40 Redline, but doesn't make sense why.
my 3way valve off the aos is about 2 years old, im gonna take it off and check it.
ill pull my aos dia again and check it too.
yes, that's a valve on the left side that appears closed, my thought was yes thats oil running down from it cause the valve edges looked very wet and ahinny in that puc. As Petza is thinking, its oil not wiped away or in the scoring. It didn't look rough or scored behind that oil, but can't be sure. That pic was cyl 4. But 3, 6, 7, 8 all look like they shouldn't for basically new plugs.
its also odd to me that its both sides and fairly even across the board, except that cyl 2 looked like the only one uneffected at all.
to me this points to some overall bigger issue, but yeah, what?
A bad turbo or turbos?
Could my cats be plugged from years of consumption and its causing backpressure? I don't even know where to begin on that front.
i don't know how to do a leak down test, ive never done a compression test, but im sure i could figure that out, or bite the bullet and go to an indy (ive done everthing else myself to this point).
Last edited by Corvetteboy6988; Yesterday at 09:04 PM.
Scope on #8, piston is up, so this is a view between two valves, bottom side of valve cover, so assuming the exhaust valves. Seems oily over a 60 degree or so area along the very top edge of the cyl wall where the head meets the block, between exhaust valves.
i saw same thing in #6.
facing upwards in the cylinder towards the intake, i didn't see the oily appearance, only when facing the exhaust manifold.
exh valves are lowest point and lower as you go from 5 to 8, again, thoughts on valve guides/seals leaking cause oul pools and sits at these low points in the head???
Down the cylinder is diagonal up to the right, but piston is up so this is very top edge of cyl. In the forground bottom left corner are the valves, fuzzy black images
the line almost vertical running slightly dia up to left, is the interface head to block.
sorry guys, i need a better boroscope
Last edited by Corvetteboy6988; Yesterday at 09:30 PM.
The DA bank is the only one that could get oil from the intercooler into it as that the side the crankcase ventilation goes back through and then the intercooler condenses the oil out of the vapor. Now is you have a turbo problem on the PS that could create oil through the intake but that's less common.
The multi-electrode plug is only spec'd for the GTs and is one heat range colder. My turbo S runs great on it and with my mods actually thought being one range colder might be a benefit with the 50% extra boost I'm running (1.2 bar). I've only had them in for 2k miles but have another buddy that's been running them in his turbo S much longer with no issues. I just like the plug design my h better as they should be less prone to fouling or wear since the spark will really only use one ground electrode until that one wears and will then go to the next closest one to the center electrode as it will have a more efficient path for the spark. This should make the plugs run better longer than a single electrode plug and I've seen those super thin iridium tips erode away to nothing in as little as 50 hours in my wakeboat engine so don't use them in there anymore either.
Here's are the ones from my boat - new one on left and the 4 I pulled from one side of the engine next to it
Oil on the threads is probably the cam cover center gasket leaking oil into the spark plug well, this gets picked up by the threads when the plugs are installed or removed.
You are torquing the plugs to spec?
I considered the Cam cover gaskets too but the Porcelin is too clean as well as the threaded body. I'm also doubting bore scoring as it has shown to start at the very bottom and work it's way up, if it was up to the top of the cylinders then you would be seeing very rough driveability and some serious smoke, long thread out there on bore scoring and Jake Raby throws in some great info. I think you're about ready for an Intake manifold pull so you can visually checkout the Inlet ports. It's not a bad job and the Intake gaskets are not expensive. Good time to check all of the cheap (as in quality not price) vacuum hoses under the manifold and your Aluminum coolant pipes (most of us have had the Aluminum coolant pipes on for years and the O-rings and attachment hoses are getting old).
Here's are the ones from my boat - new one on left and the 4 I pulled from one side of the engine next to it
The point of iridium is longevity. My Honda motorcycles (factory turbo) shipped with palladium plugs and have a 2K mile replacement interval as per the owner's manual. Standard plugs won't last 100 miles. NGK Iridium has been indestructible for me, 10K+ miles and they look like new.
The AC plugs in your photo look counterfeit...most obvious is the 1 should be under the center of the A, not under the leg of the A. The center electrodes were probably nickel.
I made the mistake of buying NGKs off eBay for my Hayabusa and got burned. Even some of the big box automotive stores have managed to get fakes in their stock.
Ha, I thought you guys might go there.
i did valve cover with spark plug hole gaskets last fall due to leaks, so the oil on the threads is coming from the cylinder up, never seen this before.
yep, torqing plugs to 19ftlbs, originally 22 when they where 1st put in.
I checked pass side boost pipe, no oil. Driver side yes, as expected, but how much is too much?
the rubber accordian hose going into the ypipe had some oil puddling in the valleys of the accordian.
Just pulled the bottom covers, i see oil under the junction of the short metal pipe to the driver turbo. I replaced the oring in there last fall, but maybe the turbo bearing/seal is leaking? That explains all the oil in the intake and cylinders? Why the rear ones more not sure. The aos drops into the boost pipe past this outlet from the turbo, so it shouldn't be from that should it?
Hah you mentioned pulling the intake, what would I be checking?
i did the coolant pipes when i bought it in 2017 with 43k as preventative. Did the starter maybe 5 years ago
If pulling the intake you check how much oil is in the Plastic intake, then look in the Intake ports and see how much oil is in the beginning of the Port (Intake Oil) and then see how much is down by the stems of the valves and what you can see on the back of the valves. Cylinder pic shows a lot of oil so if it is coming from the intake or a Valve stem/guide it should be obvious. Always a good time to clean the intake of oil. Check to see how much Carbon deposits are on the Exhaust vavles, that will give you an indication of how long it has been occurring.
IMO it's still appropriate to swap the coil and plug, more oil might just be sticking around in #4 due to a lack of reliable ignition.
Oil on the threads is probably spark plug well seals as stated, easy enough to clean those wells and then see if the oil recurs. It's not wicking up from the cylinders unless the plugs are dead loose.
Overfilling the oil can also be an issue, IMO stay clear of the very full mark on the stick, excess will be whipped up and sent through the PCV.
I pulled that metal section connected to the turbo outlet, not really oily at all in the turbo "snail" hole end. I think the drip was coming from the hard plastic hose to the turbo inlet right above it. I tightened that worm clamp but it wasn't loose.
i stand corrected, the aos does dump before the turbo outlet, in this hard plastic pipe above the outlet, going into the inlet.
I remember this from before when replacing the oring in it, that short metal section going into the turbo outlet and connected to the bypass valve never fits very tight, the alum to alum snap ring joint so some oil could easily leak out. Maybe ill get a new pipe.
There was no oil that came out of the intercooler down pipe, so that's a good sign.
I did catch these interesting pics from the inside of the outlet. "snail" part. Not sure what the heck this is, just how the turbo is cast nside, not sure what that orange is. Don't recall turbos from my other cars looking like this inside, but there are mitsubishi not ihi. You can see how clean it is.
19psi, im with you, ive never had iridiums wear out, that's why I use them, on other turbo cars, motorcycles, jetskis, etc. You do have to be careful where you buy them, RockAuto, local store, well known online store.
petza, those plugs couldn't not have been iridium.
Jfrahm,
I did nt swap the coils around, rather I put my old beru's in which were only maybe 3 years old and have no sign of cracking and test ok. I just replaced them last time I did plugs for piece of mind. Ill watch fault counts to see if #4 is still high.
i just need to figure out how to reset the fault counter.
ill go back to the new Bremis and swap the good #2 with #4 after this mini experiment with the older coils.
does anyone know what the resistence should be or how to test the coils? I check res. across terminal 1 and 3, but not sure that's correct, and then what should they read. I usually just make sure they are all similar.
I do always fill to the max line, due to my consumption, but Ive done that ever since owning it and never had a problem, but maybe that led to my problem. Maybe the redline was worse at max level and getting sucked around than previous A40 oils.
Guess ill pull the intake next weekend If I have time.
Im still leaning towards valve seals leaking, or some other unknown intrusion of oil, just don't know where else it could be coming from. Or poor spark for some reason, maybe older beru and new bremis are bad, some of them. I did fcp on the bremis, would be nice to diagnose them as bad with a resistence check, then I can get new ones under the lifetime guarantee.
I still wander about my fuel pumps. If i normally have some consumption, and if im lacking fuel, would that allow the oil to build up and not get burned off as usual? Explains my hesitation and jerkiness.
Last edited by Corvetteboy6988; Today at 12:34 PM.
Right Jfrahm, how they heck is oil wicking up the threads, I replaced the valve cover and plug hole gaskets last fall, and I am torqing plugs to spec at 19 ftlbs. There is no oil in the plug valleys at all.
My only off the wall idea was plugged cart converters and way too much back pressure, but not sure thats possible???
Have you inspected this breather check valve for the PCV system? Mine was original and the orange diaphragm was visibly torn. I have read that this can cause PCV issues, including increased oil consumption.
BobcatBrian, yes I did. I actually replaced it a little over a year ago. My original was fine, but I figured it was a matter of time before it failed due to age more than anything.
I did just recheck it last night, its all good. I wish it were that simple!
I also checked the 3 way valve off the AOS, it opens both valves going either to the intake or the intercooler hose, blowing through them if you block them one at a time. and If I suck back through the inlet to the 3 way they both close and hold suction.
I dont know a good way to test the AOS itself. I used a small blower in the oil cap, and felt air coming out the AOS outlet. If I blow or suck the AOS outlet, it builds pressure or sucks in what I added, essentially like its closed, holds air.
Last edited by Corvetteboy6988; Today at 05:49 PM.
Yesterday, 07:40 PM
