92 TOY

my little water problem.

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are you sure you are getting water / coolant in?

mcm375

Well, look at my spark plugs... does that look normal?

Also I can see the piston tops through the plug holes, they are very brown... I just can't see that being normal after 120 miles.

The white smoke doesn't go away either, now it's not a DENSE CLOUD, but its noticable when revving. Also I saw spots of water on the top of the dipstick. :|

And I should note that the oil you see has MAYBE 5 minutes of idling and a few small 3k RPM revs on it... so again, it just seems so opaque for that kind of super low duty. Additionally the 120 mile old break in oil I took out is very coffee coloured; and it went in golden.

mcm375

Here's what I mean: Left is new Mobil Delvac Super 1300, right is same stuff after the first 120 miles. No way is this not an oil/coolant mix. Top seal total seal rings BTW, so very low blow by and according to the comp test they are performing fine...



So do I go ahead and pull the intake to check that gasket? Still don't see how that is getting water into the oil though... can see how that could get water into the combustion chamber, but not into the oil. GRRR

92 TOY

I'm not trying to argue with you.

if you say you've got water, you've got water.

No the plugs don't look normal.

someone better than me has to chime in on that stuff.

Sorry I can't be of any help here.

The engine is beautiful though. awesome job!

Hope you get it figured out soon.

92 TOY

sorry, but I'm comparing your oil to mine. Your's looks to me (in my newbie / novice brain) like it's burned or too hot.
this was my oil. definitely looks nothing like your's.

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mcm375

Wow.. yeah that looks like your motor has ghoneria... lol

I think I *may* have found the problem... all my intake stud nuts (I replaced bolts with studs on the intake to head interface BTW) are showing ~100-120 in-lb of torque, spec calls for 168 in-lb (14 ft-lb). Either I didn't finish torquing them or they have loosened.

So, having borked that gasket I'm going to need to get a new one... What are the forum's thoughts on simply torqing the intake runners down properly and having a go? Or should I pull everything off the head on the intake side and inspect further? I still don't understand how a leaking intake to head gasket could get water into the oil...

After taking the upper plenum off, I see part of the gasket on the cyl 4 runner where oil has seeped through, and I see oil having collected in the runners. Looking into the intake plenum through the throttle body I do NOT see oil having collected there, so not sure if this is PCV root cause? I also don't understand how this is happening if it's not the PCV puking loads of oil through?

weaselman

well the oil in your intake runners is the root cause of your smoking issue,

and by the looks of you oil you do NOT have water in it. if it HAD water in it, it would be the carmel color in the other pictures...

my oil turned black after 2 mins of idling. i was running extremely rich. fouled the plugs, o2 sensor and destroyed my oil.

i do not think you have water in your oil dude. but if you say u do, then idk.

mcm375

Hmm, well you are quite possibly correct. The only reason I suspected water in the oil was the water droplets showing on the dipstick; could have been condensate...

So, what exactly might be the cause of this amount of oil in the runners? Assuming it must be PCV at this stage. Wondering if perhaps I had too an overfill of oil? Maybe a catch can for the PCV is in order?

weaselman

now to sure how the oil is getting there. pcv could be the cause.

its a 4 dollar part and can be swapped out in a matter of minutes.

mcm375

I guess I should have mentioned I did buy a new PCV for this rebuild...

So, I am blowing a lot of oil through one way or another. Overfill?

I'll rig up a catch can tomorrow to see.

eugenedbrooksiii

Your plugs do show serious oil fouling and the oil in your intake ports is either coming from the breather (PCV) or the intake guides. If it is the breather it will show up in the catch tank you are going to try. If it does not show up in the catch tank it is most likely the guides. I don't think that there is any other way for oil to get into the intake guides like your pictures show.

If it is the breather, your rings might not be seating properly or might not have been installed properly. A lot of blowby on the rings would cook your oil quickly, as you are observing. If it is a problem only with the seating of the rings, things might improve if/when they seat. If it is a problem with the ring installation it will be another matter. The rings, gapless ones in particular, have specific installation instructions. These instructions should have been in the box. It is also quite easy to break a ring on installation if things don't go smoothly, and you might not know that it happened.

Good luck sorting this out.

Eugene

mcm375

I was particular about following the instructions and gapping everything correctly, so very much hope that is not a problem.

Would I be correct that if compression test is showing ~180 in all 4 it is not a ring problem? Wouldn't a broken ring, or improperly installed (and thus improperly sealing) ring show a big compression discrepancy? If compression shows good (as it does) is there any point in doing a leakdown test to show ring issues?

I put a breather on the PCV and capped off the other intake-valve cover connections. I will say I have not noticed AS MUCH smoke as before, and there is none at idle anymore, though there is a little when revving... I am starting to wonder if I am simply running rich; this is what it smells and looks like (like a sooty/dark colour, not a bright white or blue).

I did check my o2 sensor with the FSM guide looking at voltage change frequency on the diag box at 2500 rpm while jumpering the appropriate diag ports; my automultimeter showed 1hz so that is > 6 times per 10 seconds which indicates properly functioning sensor.

Being that the motor still has < 300 miles on it since the rebuilt, I figure some amount of oil burning is normal as the rings seat.

I would not be happy if the valve guides or guide seals are not functioning properly as these were not assembled by myself. I wonder though, if that is where oil was leaking how would that go "up stream" and get into the intake runners? Only while the intake valve was closed? Hmm. How would one detect this, measurably?

EDIT: I have not checked proper functioning of the AFM yet, figure that could be reading incorrectly and mucking up the AFR. I did check and set my TPS and it is fine. O2 is fine as mentioned above, what else (mechanical) can affect the fuel/air mix and cause a rich condition? Have considered picking up a set of headers and bunging a wideband o2 in there to get a proper measurement of AFR.

eugenedbrooksiii

If you followed the instructions, checked the gaps, and everything went smoothly on the install, it could only be an issue of seating on the rings, a bad job on honing of the cylinder walls if the shop did a bore/hone job for you, or a miss-match between the piston size and the bore size. If the rings were the wrong size it would have shown up in the gaps. I also assume that you also checked the clearance between the pistons and the bores, making sure that the bores were sized correctly for the pistons.

A good compression test on all four cylinders, as you have, indicates that there is no profit margin in a leakdown test as this is a static seal test. Any problem you might have in the rings is a dynamic one that only appears when running the motor.

There was plenty of oil in your intake runners showing in the pictures. If you have isolated the crankcase as the source of this oil, you could clean or replace the plugs and run it a while. If the plugs don't foul again, or the intake runners don't get the oil bath again, then the source of the oil in the intake runners was blowby. If not, the source of the oil is likely the guides.

If the oil is coming through the guides it is being pulled through by engine vacuum, and the pulses that occur during operation would move it around everywhere.

Running rich won't put that much oil in your intake runners, so I would not worry about mixture until know where the oil is coming from. You will know soon, with an inspection after running the truck for while with the crankcase isolated. With the oil under control, plug color will tell you if you are running rich.

Eugene

mcm375

Just checked AFM, it seems to be reading abnormally. Am seeing well over 1k Ohms (1500-1600) at a couple of points past "open", and it generally seems to be "all over the place" to the fully open position (fully swung) where it reads 300 Ohms... Am I correct that there's only one way to fix this: Bin the bad one and find a working one?

Am assuming this could be causing rich condition. Exhaust does smell of fuel.

Replaced plugs about 150 miles ago, now have about 300 miles on motor. Will pull plugs and check condition in a few mins to see if I am getting signs of oil on them after eliminating the PCV.

Very hopeful that homeless is wrong!

mcm375

As a reminder (zoomed in and higher res) here is plug #1 from the first 150 miles with the PCV system connected:



Here is plug #1 I just pulled out, this has been run for the next 250 miles (150-400 on the new motor) during which a breather was put on the PCV and the corresponding intake plenum ports plugged:



I am hoping this is a reasonable indication that the oil burning issue was due to PCV; does it look like the condition of the current plugs (e.g., immediately above) indicates slightly rich AF mix (possibly due to the AFM as mentioned above)? It seems quite sooty for only 250 miles.

mcm375

I do see dark tops to the pistons when peering through the plug holes, so that sounds like a good explanation for the slightly higher compression readings.

mcm375

I would at least like to retract one of my prior statements that I thought pointed to oil in the water; I was stupidly checking the dipstick while the motor was running and this was resulting in oil splatterings all up the dipstick which made it appear like water splotches. So, eliminating that symptom, plus with the commentary of others on this thread suggesting I do not have "chocolate milk oil" or some variant indicative of water-oil, I am thinking at this stage I never had that particular issue... What are your thoughts?

P.S., my dipstick doesn't seal properly it just rattles around in the hole... how much of an issue could that present? Hmmm

eugenedbrooksiii

I note that you changed the plug style. It is clear that your oil fouling problem is gone (although plenty of fouling probably still remains in the head and on the piston top), so the oil appears to be coming through from the crank case. The carbon that is present could be from remaining oil that got blown through the motor, or running rich. The insulator looks pretty white for a rich condition, but you have not run the plugs very long and it can take a while to pick up color on the insulator.

Homeless was right that it is hard to get that much oil through the guides, unless it is a SB Chevy with high lift and guides that are too long. The valve spring retainer can hit the rubber seal, turning it into an oil pump. I had it happen once, another fine example of poor machine shop work in spite of careful instructions. I have been doing my own head work since then. I also have had a honing job botched, so I hone my own cylinders now as well, but the equipment to replace guides, grind valve seats, and measure bores/pistons to dial in clearances is expensive. It is also fun to do.

Your electrical test of the AFM indicates a continuity problem for the pot, provided that there were no problems in your test wiring, or the connector pins. Unless it is designed to be serviceable I always replace these units with new parts. A junk yard AFM is likely to have its own problems.

I tend to reserve judgement until all the data is in. At this point, you need to run it long enough to see if you get lucky and the rings break in. If they do, you are set. If they don't, you get to tear it down. If you ultimately have to tear it down, you will need to inspect the cylinder walls for evidence of problems in the break in wear, and check the cylinders for clearance and straightness. This will require a dial bore gauge and mike set that you likely don't have.

I have built a dozen motors and I have never had this kind of problem with the rings, although I have heard stories about such. Homeless may well be right, but it also may pay to give the rings a few more miles to see what happens. Ultimately, if they don't seat, you get to tear it down to see what happened.

If the rings seat, and you find excessive carbon left from the oil fouling to be a problem, there is a neat little trick that you can do with a fine water mist into the intake while the engine is running.

You never had water in your oil. That was clearly evident from the pictures.
You do want your dipstick to seal in the tube, as you want a good seal on any
other ways that the crank case can pick up air that then must be handled by
the PCV system.

Eugene

mcm375

Thanks for the advice Eugene, really good. I do have a bore gauge and mic set, I did measure everything up prior to assembly however the machine shop I used only bored w/ the main caps torqued, they didn't use a deck plate or bore/hone while hot so I am unsure how my 70 degree F head-less measurements would actually have ended up with the head torqued down at operating temp. My measurements were at least within spec, but hardly perfect with some slight tapering evident (though no out of round evident).

I will put a rubber o-ring around the dip stick to get a seal for the mean time until I can find a better one.

Will put another few hundred miles on it and re-inspect plugs + compression.

mcm375

Umm also just wondering, if there was a catastrophic issue with the rings e.g., broken or somehow popped out of the groove (is that even possible?) wouldn't that cause catastrophic problems immediately and be very evident on a static compression test? I am assuming at this stage "yes" and the only possible problem I could have with rings right now is whether they have/will seated in properly or not during/after the first 1000 miles.