Foxy

I've posted this all over the S2000 forums, and have been less than impressed with the responses, so I just thought I'd quickly ask if anyone considers themselves really hot on diagnosing engine problems, given a very accurate description of symptoms...

Here's the problem. All of a sudden, after a very minor oil overfill (250-300ml over), my car smoked for a day. It then stopped, and I just assumed it had burnt off the excess oil. Then on Friday morning it happened again, and went away again, then on Sunday night it came back, and again today in the morning (Monday). Now (Monday afternoon) it has stopped again...

The full story...

2001 car, with about 70k miles on it. I VTEC a LOT, the car doesn't get much mercy.

When the symptoms are apparent, it's belching large clouds of whitish grey smoke when I pull away, it's not exactly blue, but it's not white either. I'm pretty sure it's oil from the smell, and there's no white stuff in my oil to indicate a head gasket failure.

It only starts after the car has warmed up. When I stop in traffic, then pull away it belches a BIG cloud of smoke, during normal running it's a lot less, but still there. When I go into vtec (6k rpm plus) it all but disappears until I drop back into the lower rev range.

I have a test pipe, but that's nothing to do with it, I had the test pipe long before this started.

I took it to the mechanic (unfortunately, it had stopped smoking again at that point), and he immediately inspected all the plugs. They were an ashy white, no deposits of any kind. If I understand correctly, that means it's unlikely to be the rings?

I'm not very good with engines (at least not full scale ones!), but I wanted to confirm that this SOUNDS like valve stem seals?

So my questions, to be specific, are the following...

1) Would valve stem seal failure cause the symptoms I'm having?
2) If not, what else could it be?
3) What's the PCV? (I don't expect anyone except another owner will know this...
4) While the top's off the engine, what else could I look at to give me some clues about this?

It's going to go in for work tomorrow, and they'll keep it til it's fixed, but they will try the valve stem seals first. If it's not them, then I've wasted 350E, and I'll be thinking about getting a new engine to save on wasting money on incorrect diagnoses.

Any help would be, er, helpful. Thanks guys. If you want more information, be specific about what you want to know, and I'll be specific with my answers.

PLEASE - I DON'T WANT GUESSWORK.

larryf333

My Feedback: (2)

I can help with one thing. The PCV is a positive crankcase ventilation valve. Almost all vehicles I've owned have had them. If you pull it out and shake it, you should hear a little ball inside rattling. If not, it needs to be replaced.

wht92lude

yes it sounds like valve seals to me...does the car use any oil at all between oil changes? How much does it use?

Foxy

It uses the normal liter of oil per 1000km. This is completely normal for an AP1 S2000 (that is thoroughly thrashed regularly ) though.

Thanks Larry, that's helpful.

Foxy

In anyone's experience, can a failed ($3) PCV valve cause excessive intermittent smoking?

redfisher1974

I always found that leaking valve stems smoked more on startup,As the oil left in the heads leak down the stems and smoke on start up.

Foxy

Yeh, I also hear that when you let off the gas, it will smoke (if it's the valve seals). It's doing neither of those things. It's when I give it gas, and it won't start until the engine is warm. Although, considering that the problem is intermittent, mayb ehte seals are on the edge of failing, and only open up enough after the engine is hot? Jus thinking aloud. This one's got me (and a lot of other S2000 owners) beat at the moment.

redfisher1974

the pvc could be stuck causing high crankcase presure driving oil into the combustion chamber etc. Or it could be alot of things,it's one of those things that will drive you mad trying to figure it out.

Foxy

Oh crap. Update:

The PCV rattles if I shake it hard but seems a bit sticky. I'll get it replaced anyway.

The bad news is that while I was in there, I checked the oil again (warm engine, not hot, about 2 hours after turning it off) and I've used 1 and a half diamonds of oil in 30km. When it's smoking, it's consuming oil at an alarming rate, no doubt about it.

larryf333

My Feedback: (2)

Definitely replace the PCV valve. It should move freely.

redfisher1974

Sounds like its time for a rebuild.Wonder if overfilling it caused high presure and took out a seal,maybe the overfilling is more critical on a high reving motor like yours?

Foxy

Overfilling is a big issue on the S, but universally everyone said I didn't overfill it too much to cause a serious problem.

I think we've got the point where a diagnosis is possible anyway... I'll get the mechanic to do a compression test, that will tell me if a ring has failed (god forbid, cos that will mean a full rebuild). If the compression test is ok, then it's got to be the valves.

The timing couldn't be worse, I was just about to replace all the tires and brakes.

larryf333

My Feedback: (2)

Overfilling is critical on all engines. My sister's van just had the engine blow a gasket. She took it to a "Quick Lube" type place and they didn't drain the old oil before adding the new. Overfilled the hell out of it. The shop will not get the engine fixed. They said they would never do anything like that and it would be very difficult to prove they did it. Save 10 bucks on an oil change and get screwed out of 2000.

Foxy, My Honda Prelude SI used to do the same thing you are describing. Smoke like a mo-fo when I lay into the throttle, but fine when I drove it normal. I never could figure out why. I thought maybe the Weapon-R Dragon Intake I put on it had something to do with it. Almost like the vacuum created by the intake was opening the PCV valve and sucking in oil with the air. There was always some oil inside the intake where the PCV valve hose was connected and inside the throttle body after driving hard.

theRCreverend

Even a bad PCVvalve would likely not let that much oil into the intake. Your PCV (positive crankcase ventillation valve) relieves pressure that can build up inside the crankcase (the head space above the oil in an engine, passages go all the way up to the heads). A line is run from that chamber to the intake. Any pressure build up is relieved into the intake and burned with the air/fuel charge.Some older cars just vent ithe crankcaseinto the engine compartment but it smells like oil and can be dangerous (flammable).

What is interesting is the timing of this whole thing. You didn't have this problem until you overfilled your engine with oil. When you do overfill, your engine does not burn off the excess. Excess oil doesn't just get burned, in a good engine it just stays in there. If you overfill your oil reservoir too much, it is possible to actually lose oil pressure in your engine. If you lost oil pressure because of the overfill then you could have done engine damage that would result in your engine burning oil. Also, valve guide seals don't normally just go out all of a sudden. They usually go out over time.

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The first thing I would do is a compression check on all cylinders.

theRCreverend

bad valve guide seals usually don't leak once warmed up. When cold they are contracted and oil can leak thru them, causing a puff of smoke on start-up. Once warm, they swell and the leaking can stop completely

Foxy

Thanks Rev, I fear piston ring (days of labour on my car).

turbotb0205

My Feedback: (31)

what normally happens with the f20c when you overfill it it causes excess crankcase pressure and the crank is sloshing tons of oil because its much deeper than it was before.... when this happens it sloshes the oil into the skirts and through the rings causing them to move on the seat.. sounds like this may be what happened in your case....... alternatively the excess pressure may have blown the valve stem seals completely with the combination of a stuck pvc and overfilled oil

but it seems more likely its the first option as it happens when the engine heats up

if your sending it into a shop.. dont worry about it too much.. as "a GOOD shop" should be able to diagnose the issue WITHOUT replacing any parts"except head gasket and such.. that needs to be pulled to locate the issue" if their just throwing parts at it... find a different shop!

dc2 man

foxy i didnt read this thread just the top post so i dont know what in topic now but i can tell you that ALL hondas after that amount of milage use some oil.

ITS TOTALLY NORMAL.......anything vtec as its a racing engine will use oil,my spoon integra r uses some cause it redlines at 9500 grand...........

all vtec hondas start using oil and its harmless,it is valve seal related that and slight piston ring wear.....again harmless.........

these engines could stay running for 300kmh burning slight amounts of oil,it has zero effect on relibality.

i do know what i am saying as i have hondas all my life.
some 1600 sir civic owners here use large amounts of oil and engines run perfect.

i once had a car garage man say to me that some use oil BRAND NEW.........


nothing to worry about,only your s2k is getting older.

i always use semi syntetic oil 10w40

Foxy

We use 5w40 in Greece mate, it's a liiiiitle bit hotter than Ireland.

Read the whole thread, I honestly think I'm about to have a catastrophic engine failure. In the very best case it's the valve seals, but I now think it's a ring.

Foxy

Thanks man, my guy has a Honda racing team, so he is pretty good, he's just been too lazy to look at it properly. Like everyone else he thought it was something insignificant at first, but now I know it's definitely not. In any case, I didn't overfill it enough to damage it.

dc2 man

man i dont know what to think.....i have never heard of that happening a honda engine.i though you were referring to a little oil burning but from what your saying it sounds more serious.

was car driving alright before you took it to garage? apart from the obvious...

you sure 5w40 is correct oil grade?

sounds very light for a vtec engine.
these engines rely on hydrolic pressure to open lobes and increse cam profile {{vtec}}

check out your oil again.

Foxy

Dude, with the greatest of respect, I'm no noob. Of course I'm sure that's the correct oil. Besides, the service manual for the F20C says to use 10w30, we use a slightly THICKER oil (5w40) because it's much hotter here than in Japan. Also, the vtec engines need light oil. It's well documented. The Greeks are actually much better with engines than the British, it's just their driving that sucks. lol.

When looking at oil viscosity, the w means Winter. In other words, the 5 is the COLD viscosity, and the 40 the hot viscosity. In vtec engines you want a low cold viscosity so it circulates quickly, and a reasonable high temp viscosity. You are using a good oil for your climate, and I am using the correct one for mine.

Let me put it in perspective for you... In 30 kilometers, I've burned nearly half a liter of oil, and the clouds that follow my car would support at least 2 fat little angels. Normally my car burns the standard 1 liter per 1000km, as I stated above.

I wouldn't be preparing for a rebuild if it was something simple. In the very best case, it's the valve seals. Otherwise, it's a ring, and therefore a rebuild, cos a ring will have chewed my cylinder to bits.

By the way, it's happened to a lot of F20Cs, it is very unusual, but it happens. Don't forget I didn't own this car for 90,000km of its life, so I don't know what's happened to it.

dc2 man

jezzz man im speechless.....

i wish you the best of luck with it.hopefully it may turn out something minor......

now it makes me feel i must drive mine a little easier more often as i ring its neck all the time......

man thats a bi#ch..........

i wasnt employing you didnt know your oils,i just couldnt believe a viscosity like that would be used.but as you say yes you have a much much hotter climate,i forgot you were in greece lol

best of luck with it man.

Lunchboxer

Can't help you Foxy, but good luck!! If you need to re-build it, will you re-build it stock or throw some hop-ups in?!

Anyway, hopefully not something serious!! Good luck!!

Foxy

No worries man, thanks for trying to help anyway.

LB, thanks, I too SO hope it's not as serious as I believe, all will be revealed in about 12 hours time.