dth0ng69

Okay So I had a long semi-frustrating journey of fixing a Oil seep that seeps from the square hole of my engine stiffner.
I thought that the seep was coming from my oil pan gasket, which I replaced and where the confusion began. (My old Post https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/replaced-oil-pan-gasket-still-seeping-help-2610576/) sorry for camera phone Pics.
I have a 1998 civic with a d16y7

Heres the picture of where the oil comes from.


When I took the exhaust, stiffiner, and flywheel cover off to get a better look I start to think that the seep is from the rear main, but I'm not too sure.

I took a picture of the inside of the Flywheel Cover, and it is kind of greasy.


Then took a picture of the flywheel and it looked a little greasy


When I swiped my fingers around the housing for the flywheel heres the really black Oily substance that I see


what I'm confused is, why is the oil substance that is in the flywheel housing really black?
If it's leaking oil from the rear main seal wouldn't it be fresh clean oil? (just did a oil change)

And my other question is Should there be any greasy black oil, in the housing of where the flywheel is at all? or should the housing where the flywheel is, be completely dry?

A honda tech told me if oil is leaking out of the hole on the stiffner it can only be the oil pan gasket or the Rear Main seal.

Thanks so much for reading, I'm really stuck on this one..
help would be appreciated.

Former User

Given that the oil pan gasket has already been replaced and that this did not fix the leak, then the rear main seal almost surely is leaking. Regarding the dark black versus fresh look of the oil, I think there has been a slow leak for some time, allowing the leaking oil to mix with dirt and grime. In addition, your engine oil likely becomes a bit dark as the next oil change approaches.

Is it about time for a new clutch and tranny anyway?

dth0ng69

I litteraly just changed my oil about a week ago, I seen very little spots on the oil pan gasket that was wet, but since the oil that is coming out of the engine stiffner is dark I think I should replace the rear main. any thoughts or help?

dth0ng69

I'm kind of confused, some people were giving me suggestions like to check the distributor O ring, cam seal, and valve cover. But a honda-tech on here told me if oil seeps from the little square of the stiffner it can only be the oil pan gasket, or rear main seal... I'm pretty stuck

92ehatch

could be the dizzy o ring as well, it will run down to the same place.

however, your pics show a rear main for sure.

the reason it is black, is because the oil is mixing with the dust from the clutch.

dth0ng69

thanks 92ehatch, I see your point.. I think after I tightened the 2 bolts of that side of the oil pan it started to seep slower than usual.. If it keeps seeping this slow, I think I'm going to wait till I have to replace my clutch and have them do the rear main along with the clutch so it would be less labor. Or find a time / place where my friend and can do it...

flyjazz

In the first picture,does anyone know what the drain/seep hole is technically called? Is it designed to specifically keep the clutch from getting damaged with oil building up from a leak and does it also serve a secondary purpose in pinpointing a leak? As an example,if oil is only leaking from the seep hole,does that suggest that it's a rear main seal? Of course it could the the transmission seal,but would that not likely be what causes oil to get on the clutch then giving clatter(of course determing that would be moderately easy as you just need to check the oil level in the transmission). I noticed there is also a drain/seep whole at the front of the engine,again same purpose,to avoid damaging the timing belt and giving an indication that one of the seals is gone. So now if one is getting a little seepage out of the rear main drain/seep hole and oil running down the side of the oil pan near the rear main seal,would it be possible that it's just the oil pan gasket leaking underneath the rear main seal where most goes down the side of the oil pan but some of it leaks over into the flywheel housing and out the drain/seep hole?