My gsr lost at least a quart possibly 2 quarts over 2500-3000 miles of driving. i do not hit redline very often at all, maybe once every two weeks or one week. there is no leaking from head gasket, vc gasket, or anything in engine. coolant seems to be right color. I left a cardboard overnight and there was not a single drop. the engine does not have grey smoke at start up, and the only time i've smelled burnt oil is when i get near redline, which is not often and fairly common with b18c1 motors.

with that said, does anyone have any suggestions as to where my oil is going? i've read that spun bearings can cause drop in oil pressure, but does it actually cause oil loss? the engine has about 94k miles. there is a slight clicking sound from the motor but it doesn't seem loud enough to be a knock. the car gets 28-29 mpg consistently, and power is definitely there at least from my butt dyno from daily driving (not engaging vtec for dd obviously). please help me out, thank you ht!

 

you need to do a leakdown test to determine whether it's the rings or the valve seals. it's one or the other.

 

A compression or leakdown test won't tell you anything about your oil control rings or valve stem seals so there is no reason to do it.

 

I'm going through the exact same thing with a b16 with 140,000mi.

It's a mystery because it doesnt blow smoke on acceleration or deceleration. Seems like I'm blowing a lot of oil out the PCV, so I'm interested to see how the compression turns out...I could be that a lot of blowby is causing it to push a constant oil spray out the PCV system.

Could also be stuck oil control rings but as said you cant tell that from a compression or leakdown, but if its bad enough you should see it poof blue smoke upon acceleration. Now that finals are over, I will be looking into this more...

 

yep, scott's right. i was thinking valves rather than valve seals.

 

If your engine is running rough you can do a compression test but if that is the case your oil consumption is not your main problem. Does this engine smoke at all? Does it have a catalytic converter?

 

Technically, according to Honda specifications & most all manufacturers, oil usage of up to one quart in a thousand miles is "normal" and okay. So, with your numbers, you can let it go. However, I think we all agree that losing a quart in a thousand miles seems a little much.
If you're not leaking oil, then your using oil (burning oil), no other option.
If you aren't getting blue smoke, then you are burning atomized oil. That's commonly caused by worn valve guide seals. When the intake manifold has high vacuum there is one seal (actually 8) that has to withstand that pressure... the intake valve guide seals. Even though the valves might be closed in that one cylinder, the valve guide seals are still exposed to the intake port which is exposed to the intake runner which is exposed to, you guessed it, the intake manifold. So what happens when you have a large vacuum pulling at worn valve guide seals is that oil gets sucked into the intake port, atomized from having been squeezed through the tight clearance between guide & valve stem and exposed to vacuum, sucked into the combustion chamber on the next intake stroke with the air & fuel, and completely burned during combustion.
If the piston rings (oil control rings specificly) were the culprit of your oil loss, then the oil would not be fully burned in the cylinder since it doesn't get atomized during that manner of leak, and you'd get your classic blue smoke. Another way to determine if your oil control rings are failing to do their job (on a B-series), pull your spark plugs and check for black gunk, heavy carbon build up, or even a dark brown slimey sticky goo. If they look fairly normal then again, probably the valve guide seals.

 

there is no smoke coming from the motor at all, upon first start up of the day, there's a little bit of white smoke (very faint) for about 10 seconds. motor pulls strong, yes i have a catalytic converter.

 

thanks a lot, i'll check out the valve seals after finals.

 

Here is something I wrote for another post a few months back that I kept since the topic of oil consumption comes up so often:

Doing a compression test to check oil consumption is a myth that keeps spreading. The oil control rings on the piston control oil, not the compression rings. The compression rings only seal compression, they do not control oil. You could take the oil control rings off the piston and run a compression check and it would be higher than originally due to the oil entering the cylinder. Valve guide seals don't seal anything but oil anyway plus they are outside of the cylinder so they don't show up either.

If your PCV system is OK then there really is only two ways to get oil into the cylinder to be burned. Either the valve guides are not sealing due to excessive valve guide clearance or faulty seals or the oil control rings are faulty or stuck in their ring land due to carbon/varnish build up.

The valve guide seals themselves can get dried out and brittle and not seal but more commonly on a higher mileage engine that has been beat on the valve guide to valve stem clearance is excessive which wipes out the seal as the valve stem rocks around in the guide. Putting new seals on valve guides that are excessively worn is only a temporary repair and the new seals will be destroyed in short order.

Generally you can diagnose your oil consumption problem with a simple test. The problem with this test is if you have a catalytic converter it may mask the problem and you will have no smoke out the exhaust. If you have a cat it is better to do this test when the engine is dead cold so the cat hasn't had time to heat up. If you can install a test pipe in place of the cat that is even better. Get on a road where you can do full throttle blasts in 2nd or 3rd gear up to redline. Get the car moving and put it in 3rd gear and at about 2000 rpm put the accelerator all the way to the floor up until redline. If the engine smokes while you are accelerating you have faulty or stuck oil control rings. Then, after you have gotten to redline let your foot off the gas but leave it in gear so you are engine braking. If it smokes while decelerating then you are getting oil past your valve guides due to wear or faulty seals.

The reason accelerating causing the rings to pass oil is something called 'pumping' when there is excess oil on the cylinder walls because the oil control rings are not doing their job. As the engine is under load, the gas pressure (when you are decelerating there isn't much pressure in the cylinder) and motion of the piston physically pumps oil from below the rings to above the rings and into the cylinder. There are holes or slots on the piston behind the oil control ring land where oil can drain through and back to the crankcase. These holes or slots are not present on the compression ring lands. The thin oil control rings physically scrapes the oil off the cylinder wall and out these holes or slots.

Oil is consumed through the valve guides on deceleration because you have the throttle slammed shut and the engine rpm is high. This cause very low pressure (high vacuum) in the intake port at the outlet of the valve guide. the oil is 'sucked' through the valve guide due to the higher pressure in the crankcase. Oil doesn't go through the valve guides during acceleration because the pressure in the intake port and the crankcase are approximately equal at WOT (Wide Open Throttle).

 

What is your opinion of what happens when the valves run on the vtec cam lobe? I've heard that crap that builds up on the valve stem during normal driving gets pushed down into the stem seal when vtec kicks in. Do you buy into this theory?

 

There is no reason that the engine should burn oil only on the vtec lobe. It's open the same valves with the same seals so it doesn't really make sense. Plus oil will only be pulled past the valve guides on deceleration and you rarely are decelerating in gear at that high of an rpm. Oil burning on accel will be caused by the oil control rings. I think it has more to do with the higher cylinder pressure at those rpm and the shear volume of gases passing through the engine.

 

I agree on accel vs decel consumption. My thoughts were that periodic vtec use could contribute to overall valve seal wear....not just worn guides. I believe the vtec lobe is a bit more aggressive so it pushes the valve in further, no?

 

Yes decel with the throttle closed & in gear does create the largest vacuum in the intake manifold, but anytime the throttle is closed the manifold is under a pretty strong vacuum. So if the valve guide seals are worn, then that's when the oil will be "sucked" past them. With the obvious greatest oil loss in this manner coming under high RPM closed throttle decel in gear.
Your statement about VTEC opening a valve further (pushing it down further) is correct. The statement of gunk building up on the end of the valve stem above the valve guide seal is also correct. If you don't properly maintain your oil, and rarely using VTEC contributes further, then yes the top end of the valve stem can get carbon/varnish/gunk built up right down to where the valve guide seal is on the stem when the valve is fully opened by it's corresponding lobe (primary or secondary). The VTEC lobe is the mid (middle) lobe, and does open both valves further than the primary & secondary lobes. If you rarely use VTEC and improperly maintain your oil and have built up varnish, gunk, & especially carbon, then when the engine goes into VTEC it will force that rough "wider" section of the valve stem back & forth through the valve guide seal. That's going to add to the seals wear. Scott_Tucker is right about valve guides getting worn (ovaled) contributing to the valve guide seals leaking. This is generally caused by excessive high revving (not over revving the engine which creates valve float and that's a whole other issue). Honda's aren't as susceptible to this as some other manufacturers are, but it does occur. Unfortunately the S2000 is one that is more affected by it, and actually ends up causing another concern instead of oil consumption.

 

Bad news. Here's the results of my compression testing, warm engine, WOT, 5 crank:

193 psi
195
191
161

191
195
190
165

Looks like it may be my blowby theory from that one cylinder....

 

That engine must have run rough. Did you do a wet compression test?

 

IDK, maybe the first owner who put 30,000 mi on it ran it rough, but I don't.

Didn't run a wet test because I didn't see any posts saying how to do this without hydro locking the engine. Looking through the plug holes, the tops of all the cylinders are covered in carbon deposits.

I do see oil in the PCV valve.

 

I believe Scott_Tucker is referring to adding oil for the compression test (wet test). That's fairly easy, before you put the gauge in the cylinder, put several drops of oil (not a stream of oil) into the cylinder through the spark plug hole. If you have an oil squirt can that would work well. Let it sit a second or two then run the test for that cylinder. Repeat for each cylinder. In you're case, you really only need to check that low cylinder. If it comes up then the leak is in the rings, if not it's in the valves. Either way, if you're going to repair it then you might as well do all four.

 

2 teaspoons it is...
http://www.team-integra.net/sections...ArticleID=1086

 

Tested it after a 200 mile drive and now I'm getting about 200 +/- 5psi across the board. Maybe it wasn't hot enough last time......Drove it for 20min, changed oil and then tested.

 

i read through this but i would like to make sure i got the major points right. i do have a cat, so would doing wot when the engine is cold a bad idea?

next, as for diagnoses, smoke while accelerating means i need oil control rings, while deceleration means faulty valve seals which could be due to valve clearance, which means i should have the valves adjusted while i'm replacing the seals correct? thanks!

 

You can go WOT when the engine is cold. It's not something you want to every day but it shouldn't hurt the engine. Yes, smoke on accel means rings, smoke on decel means valve guides.

It's not the valve clearance that could be the problem it the valve guide to valve stem clearance. It's not something you can accurately measure when the head is still on the car. If the cams are coming out you do need to have the valve lash (which you are calling valve clearance) checked, though.

 

Bruh its either, FURSURE YOUR rings, or Valve seals. gotta be, 100 percent sure/,.

 

Do a series of tests first, wet comp test then also try emptying your oil, then when it's empty, refill it again. If that doesn't help you, have it checked from a shop.

 

What does that mean?