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Can someone post a photo of the underside of the oil cap and it's gasket? Mine's flat. I would assume there would be a slightly protruding gasket but it seems like there is a soft rubber gasket that's along the flat underside of mine, so I'm not sure if I've got it or not.
Originally Posted by Car Analogy
The gasket is a square sided o ring. So its flat. Might be easy to miss seeing it.
The OEM oil filler cap gasket is indeed square/flat:
The aftermarket one I bought has a thin ridge running in the center and I can feel the rubber gripping and compressing when tightening the cap - with my 13yo one I felt nothing
This is a genuine Mugen oil filler cap (I know ours is different but it is easier to spot the gasket on this one) and the location of the gasket is identical to our OEM oil cap:
The OEM oil filler cap gasket is indeed square/flat:
The aftermarket one I bought has a thin ridge running in the center and I can feel the rubber gripping and compressing when tightening the cap - with my 13yo one I felt nothing
This is a genuine Mugen oil filler cap (I know ours is different but it is easier to spot the gasket on this one) and the location of the gasket is identical to our OEM oil cap:
The backside of the OEM gasket is square, the contact side has a lip. You have to install it properly
Great.
The rubber on my OEM cap has no lip, is hard and i dont have a "Rubber is compressing feeling" when i thighten the cap. And my engine needs Oil.
Coincidenly, I happened to land on this post, and after the reads.... went to go check my own ap1..... low and behold there were signs of oil leaking from the oil cap.
And no gasket.
Just did a oil change yesterday as well, checked the oil level and the oil is below the low level... cheezus christ.
Yeah, get a new OEM filler cap seal and tighten the cap snuggly. These things have a tendency to come off, if not torqued down. I use a small rubber mallet to ensure tightness. Which requires small rubber mallet to remove.
Fortunately, my S2000 or Element doesn't burn oil. But, I did lose the OEM cap from the Element, when a friend replaced the oil, but did not make sure cap was tightened properly.
Lol, I hope y'all don't take this the wrong way...
I feel like I'm gonna go down in history as the oil cap gasket guy... instead of the guy that said check crankcase vacuum/pressure to ensure ring sealing with FRM liners on NA. FI has the extra pressure to push the rings out.
I'm really hoping someone else with a high burn rate shows up and takes some of these same steps.
Milage - quarts
213616 - purchased full 6/8/18 Compression 208 208 210 210, <6% leakdown. Motor checks out as healthy. Engine bay clean, me unaware of how large the oil consumption is. Seller noted top it up at fueling. Car seemed extremely well maintained. To the original owner, the consumption probably gradually increased, and just became habit to top off - but not document how much consumption. Received a stack of service records as thick as the service manual.
At this point I was down to about a quart every 2500. I stopped recording my 0 inputs and only noting actual inputs
223251 - 1/5th
Current Milage 223893 1/9/19. Anyway, sorry for the tirade, But this was gathered over about 10k miles in 6 months. I wanted to bring this to light because the gaskets that were leaking, weren't leaking enough to drip and stain except the TCT/VTEC/Oil Pressure switch. Yet my consumption was quite high without floor stains, meaning I must be burning it off.
How can I burn it off if my compression and leak down are good if not damn near perfect? The fixes all correlate to crankcase pressure, which also is the same things you see in B21Bs, H22, H23 and C32B with FRM liners.
All of this wouldn't matter much on FI, as the increased pressure helps seal the rings. (unless of course you have bad na compression/leakdown and scored walls).
Alright I've said my peace, I know the oil cap gasket is low hanging fruit, but the total cost of all of these gaskets is in the order of about $100 from Majestic, $140 with valve stem seals, 04-05 Valve covers can be had used or new for the switch to a horizontal pcv. All in all this whole ordeal is filled with "low hanging fruit" in terms of cost and ease - with the exception of valve stem seals, most everyone should be able to do these fixes quickly and cheap themselves. There's hope for your burning AP1, but you have to be willing to bring the crankcase ventilation and sealing back up to par.
Just think about how much an effect most intakes have on this car compared to OEM, most lose power. Now think about how well honda must have engineered the efficiency of the crankcase ventilation, and then degrade that ever so slightly, kinda like intakes, small changes, make big differences.
Edit: This whole thread/post was caused by alot of staring and drinking and thinking. For example. I also just figured out my buddies oil burning issue on his 1000HP m52 I6. He built the motor, and boosted, now it burns oil. Everyone in the bimmer world says its your valve stem seals or oil control rings, as he was getting oil in the intake and exhaust runners, but not in the charge piping. Needless to say a bunch of people sent him on a round about. I took one look and a long stare, and said "Your turbo is top mounted, without a restrictor, and the drain is to low on the oil pan, its backing up and blowing out the seals" Of course everyone and him say nooo thats not it, how does oil get to the intake runners but not the charge piping. I again answered "Top Mount, Gravity, Scavenging, and Overlap". Sure enough, I was spot on. Sometimes you really need to think outside the box and understand all the physics of the assembly to find the answer that isn't necessarily clear with conventional thinking
Deckoz when you measured crank case pressure did you only check this at idle?
It would be interesting to see how much it changes during the rpm band, at higher loads I'm thinking there wont be much vacuum left at all.
01-07-2019, 01:36 PM
