Engine oil can burn just as quickly as it can leak, and often this is the case. If you are using your rear view mirror to look for smoke out the tailpipe, please know that it’s not a great method. Firstly, your mirror reflects what you see above your trunk/hatch. That’s about 2 feet, give or take, away from your actual tailpipe. Secondly, when driving, the faster you go, the velocity of the air streaming past your car is increased and this air will often mix with and dissipate any smoke before it becomes visible....

You seem to have checked multiple times for an oil leak and have found none. Oil could possibly be leaking only while the engine is under load. A dead give away for this would be oily suspension parts. Let’s assume though that your car is not leaking, and is indeed burning oil.....

what are the ways in which oil can be lost substantially due to burning? It’s got to be one,
or perhaps a combination of the following issues.

-worn piston rings
-worn valve stem seals
-pcv valve
-compromised head gasket
-cam holder seals
(on non vtec heads there is possibility of oil seeping past the cam holder seals and entering the combustion chamber via the spark plug threads. A dead give away is oil on TOP of the spark plugs. Not applicable for vtec d series heads due to spark plug tube design.)

If you want a quick way to see if you might be losing oil due to piston rings, buy a can of Engine Restore. It’s available at most major auto parts stores and Walmart. It comes in a silver can and it’s cheap, like $7.99. If it’s your rings, and you are having serious blow by, this product will temporarily decrease the blow by substantially, lowering oil consumption, while increasing your compression to spec levels, and also felt acceleration as a result. If you use this product and don’t see/feel any noticeable difference in oil loss or performance, I doubt your rings are to blame. At least they are not 100% to blame.

if rings are out of the equation, then you should check the pcv valve. Check the tube connections
on the head and intake. Are they very oily? Check the intake tubing between the throttle plate and the pcv connection. Check the throttle plate itself and see if you can shine some light into the manifold. Is oil residue caked up in any of these areas? If so, you have too much oil entering your intake
system which then exists the tail pipe after being combusted.

valve seals and head gasket are difficult to check.... if you believe it to be either of these, you’ll need to get ready to do some work. There’s really no way to “check” the head gasket, you’ll just have to replace it. Valve seals can be “checked” I guess but I’m not sure how well very old valve seals will respond to being removed and reinstalled. They’re pretty cheap to buy, but anpain to install being that there’s 16 of them.

on a side note, you mentioned improper timing and a very rich running condition, as well as possible
soot buildup burning off, all I can say is get your timing right..... And if you think your engine is internally dirty, try putting some sea foam into the gas tank, and a little in the crankcase and run it for like 500 miles then change the oil. It should get things nice and tidy inside of there.

Disclaimer: I am not a professional mechanic nor do I pretend to be one. The advice given here should be used at your own discretion.

Yeah, the timing was wrong, 1 tooth to retarded and i don't know how long the previous owner drove it like this, but there is much build up on the top of the pistons. I changed the timing belt and set the timing right, so could the old "soot" burn away and causing the black smoke and black spark plugs?

About that restore thing, i think i will wait till monday and check the compressions, then i know how (or if) bad the rings are.

I already changed the pcv valve, and cleaned the tb, there was some oil in it but not much, almost clean. But the intake mani was a bit dirty...

i do know that the dipstick tube isn't sealing alright but i do not know if the gaskets for the vtec solenoid / dizzy are good. But the dipstick tube is the nearest to the oil pan, so if this isn't sealing, it would cause much oil loss, right?

i think i am gonna have to wait till monday. Or is something that i could check out/do? Maybe i drive it a while tomorrow and check all gaskets (cleaned engine today) if there is any oil leak, because under the dizzy and vtec solenoid it was all black and sooty. Still hoping that it's gaskets or just valve stem seals, but again, no smoke on cold start today and no smoke during the downhill test, so i am guessing f not the gaskets = rings.

Okay. Well if your dipstick is not sealing, I guess it could leak oil but it would probably only do it under load/ high revs and this oil would probably drip onto your down pipe and get burnt up..... I currently have an integra that leaks oil from the pan gasket and this mostly drips onto the downpipe producing visible smoke coming from the front of the car at stop lights.

i doubt you’d lose much oil through the distributor without seeing it on the ground.

if you do your compression test, and it’s low.... this could be from worn piston rings, or valves that aren’t completely closing....they could be clogged with buildup. If I were you, regardless of the compression test, I would definitely run some seafoam through the fuel system and the crankshaft to clean things up.... you could even drip a little directly into the combustion chambers through the spark plug holes and let it sit overnight.... then change that oil out and put in some engine restore with like some rotella T5 5w40 And run that for a while. See how it feels, and see if consumption goes down. It’s a cheap way of narrowing the field of possibilities.

If your valves and and rings and all that seems fine and you’re still losing oil, (you said you lose oil even when it’s parked?), I’d have to think that maybe you’ve got a breach in the head gasket that’s allowing oil to seep into the combustion chamber. I’ve never seen this actually happen but I’ve heard that it’s possible.

One thing to consider, is maybe you’re not losing the oil, maybe it’s just not getting back into the oil pan as it should. How quickly did you check the level after shutting the engine off? I think the dipstick measures about 2 quarts of oil, so if you were 2 quarts short, the oil would barely register on the tip of the stick. Also did you do the compression test? Perhaps you have clogged oil passageways in the head... idk you stumped me. You should take my advice and run the seafoam, hen run the engine restore and get back to us. It will cost you almost nothing, and I almost guarantee your engine will run differently, maybe better....

What the problem is though? No way to find out for sure short of tearing your engine apart...

Not understanding this response. You checked it today and oil was at max without adding more oil? If so, yeah, your oil is not returning to the sump in good time. This is a potentially dissasterous condition that will lead to more and more wearing of the piston rings and potentially the bearings themselves.
i might be wrong, but I think it’s one quart between the lower mark and the upper mark. It’s another quart between the lower mark and the tip of the stick.
i would imagine its the composition of the products, not the result of using them that makes it illegal. Restore has lead in it so.....
Im not an expert at reading plugs. If you have oil on your threads, and you have a non-vtec engine, then you need to replace the cam holder seals. and if you have a vtec head, I don’t know what that means. You can definitely stick something through the oil passages, the blockage, if there is one, could even be in the block so.... good luck with that. You will need to remove the valve cover to access all the passages.
Well, when the engine is at rest and you add oil, it flows down through the main return passage near the fill cap right into the oil pan. But when the engine is running, the pump sucks the oil through the pickup and the oil is supposed to be distributed throughout the head and block. And it returns through more than one passageway... there’s a lot of areas where oil could get stuck....



I’m beginning to enter the realm of pure speculation at this point. I do believe you are in need of an engine tear down. You should at least take the head and oil pan off the block and inspect. The head should probably be sent off to the the machine shop for a good hot tank bath and pressure check. The block needs to be blasted with some solvents if there is sludge buildup... I think if you do this, you may end up with a properly running engine, or you may realize you need a new engine/rebuild.

Typically, there’s nothing to rebuild in the head... the only thing that can really get damaged is the valves by bending, chipping, cracking etc. or the cam can get damaged from low oil pressures, that is called cam wiping... the head can be removed and sent to a shop to be soaked in a hot bath of solvents and come back shiny and new-ish. when you say “engine rebuild” it’s typically meaning the lower end.... Piston rings, rod bearings, and main bearings.

A compression test alone will not tell you whether you have worn rings or leaky valves, or a combination of the two. You’ll only know that compression fine or out of spec, and you’ll know whether it’s one, two, three, or all cylinders that are low and by how much. If you’ve got low compression on all four cylinders but they’re within 10psi of each other, then this is just normal wear and your engine is old lol, look to the rings to be bad. If you have one or two cylinders that are Drastically lower than the others, then this means the problem is localized and you need to look into why those cylinders have no compression.... you need to remove the head to properly do this...


If if you want a less painful way of going about this, I would leave the engine that’s in there alone and I would buy a really cheap old engine and have your mechanic or yourself rebuild it to spec and just swap it in. You could tear down the engine that’s giving you problems just for curiosity. And hang onto it for the spare parts Incase you need them down the road.

if if you want to clean up your engine using over the counter liquid products, then you need to add one product to the FUEL to clean the INSIDE of the combustion chambers, and another product to the OIL to clean OUTSIDE of the combustion chambers.

You lost me on wet and dry testing.... I don’t know what that is.

Pulling plug wires to see how the engine responds is for locating misfires not compression.

$170 for head and block? Sounds like a good deal. Is the engine sealed or open?

Dry = just normal compression test
Wet = with 1 teaspoon of oil in the cylinder

Yeah it's sealed. but i don't know, maybe i am going to put an b-series in it if i change the engine anyway. But i'll first do the compression test and have a look on the results. when i looked into the spark plug holes with the flash light, the cylinder walls haven't looked that bad. Just like 160k miles old cylinder walls look like. but i have seen some oil/gas on top of the pistons and after running the engine hard and pulling the plugs out, it kinda smoked out of the tubes from the cylinder.

wouldn't oil on top of the piston mean that something on the head (valves, stem seals, or something) are bad? or is there an other way that oil is on top of the piston? Maybe the 1 tooth to retarded caused the engine to build up some carbon on the valves, and these are not closing fully anymore? could that be possible?

carbon buildup on the valves is very possible. But if your compression was that low, you’d feel the loss in power. Oil on top of the piston?.....you said you have oil in the spark plug threads too so I don’t know....If your heart is set on a new engine but this one is running strong, don’t over think it, just drive it till it stops running.... and save up that repair money to buy a new engine.... ****, if this engine runs long enough, and you keep saving, maybe you could buy a nice German car! Lol jk.

If you Take the valve cover off of your engine and look INSIDE one of the valve springs and you’ll see a valve stem. This stem is exposed to oil that flows through the valve train. If you get a flashlight and shine it at the very bottom of one of the spring seats and you use a magnifying glass or something you can just see the valve stem seal sitting inside of each spring. This seal is like a tiny rubber bowl flipped upside down, with a hole cut into it, just big enough for that valve stem to fit through. The actual sealing action comes from a super tiny donut shaped spring that’s molded around these tiny holes. This spring squeezes the rubber in on the seal reducing the clearance to a point that’s just too tight for viscous oil to penetrate......

bear with me.......

........over time, friction, dirt, heat, oxidation, and other forces can cause the integrity of these valve stem seals to deteriorate resulting in a loosening of that tiny spring and a slackening of the stiffness of the rubber moulding. This creates an enlarged clearance between the seal and the valve stem. Now oil can penetrate this space and leak down the valve stem on both the intake and exhaust sides, and this oil now partakes in all four of the engine strokes. Oil is coming in on the intake stroke and crudely homogonizes with the air fuel charge. this tiny atomized oil then gets compressed as well. (It’s my thought that this little oil probably increases dynamic compression?) on the ignition stroke, the poorly and unevenly dispersed oil burns and sticks to the chambers. Then on the exhaust stroke more oil flows in and gets baked onto the valves and this oil is now bubbling and burning and getting blasted out the exhaust, causing infamous blue smoke....

......this oil also can form into very hard deposits.!hard enough to cause a valve not to close... again this would result in compression loss on that cylinder. But actually this would probably only happen if the oil was allowed to get low enough to case the oil to really dry and fry and get hard. If you have this condition and oil is kept up and is constantly flowing into the cylinder, the oil just keeps flowing and burning, and this engine will run for a long time....

Sounds like your Engine was abused by the previous owner and now it has a chronic condition that needs to be treated with fuel and oil additives. Add a couple ounces of some type of ethyl to your gas. Can you get Lucas fuel cleaner? Use that. Can you get marvel mystery oil?

So, today i checked the oil again, was the same amount in it. pulled spark plugs and had a look into the cylinders. 1 & 4 is dirty and with much build up on the piston tops while 2&3 are clean and have oil/fuel on top of them. Made an video while i was revving, and i see some blue smoke, but after driving a couple minutes, and revving again there was no blue smoke anymore.. pulled the spark plugs again 2&3 - black build up while 2 was a bit "glossy". 1&4 - normal.

while revving there was some black soot coming out the exhaust again, i don't know but i don't think that it's oil, doesn't smell like oil and after an day raining it's away from the ground, also it's really thin, like water with some carbon build up or something, don't know the last 2 days it was cold and raining here, maybe it's because of that.

compression tester has arrived, after work i'll check the compression's in each cylinder. Dry and wet. Let's hope for the best, lol.

and yeah, i think so too. The previous owners abused the engine, the car is pretty clean, and every previous owner was older than 30 so i don't think any of them over revved it or was hitting the redline every shift. I think some previous owner missed some oil changes or ran low on oil or something, never warm up the engine, etc...

135 min, 180 good 210 max, no differences higher than 10%, right?