MyUsernameName

I don’t have the tools to check it or anything but it’s leaking from under the passenger side of the car. It’s slowly leaking. My cousin noticed it A few days ago when I parked my car in his driveway. It’s not leaking a lot but it’s noticeable. Any idea what it might be? Thanks!

EDIT: Drove it for a few days after they change the o-ring and now oil is leaking under the driver side of the car. It’s leaking bad to the point where it’s leaving a trail on the street. Luckily my mechanics shop is down the street. Will update on what it is.

EDIT2: My oil pump seal popped out. They did an oil change and had to do the timing belt. Total cost was $314. $35 oil pump seal - $25 oil change. $250 labor.

Aradin

4 cylinder or V6? is it brown/black oil or more of a red color?

MyUsernameName

4cylinder and the color is brown/black.

Aradin

My guess would be rear main seal or oil pan then since it's toward the passenger side.

Rear main seal replacement is a fairly big job and requires removing the transmission.

Oil pan is easier and would just need to be removed and resealed. I believe your vehicle simply uses silicone/Hondabond in place of a traditional gasket.

MyUsernameName

thanks, I’ll head to the shop soon. I’ll keep you updated on what it is.

Buffalo.Rider

It is certainly possible that it is the the rear crankshaft seal (or possibly a transmission seal). Since it is a 1999 vehicle - if these seals have never been replaced, you could have a slow leak there. Oil pan gasket is another possibility. Valve cover gasket, if older, is another possibility - do you have a lot of oil all over the motor? If yes, your valve cover gasket should be replaced.

HOWEVER, there is another possibility that would be my best guess on what it is. I had an oil leak problem on a 2000 Accord and this was the problem. My problem turned serious enough that we could not drive long without losing too much oil to drive the car. And it is/was in a spot that is pretty unobvious. There are two rubber O-ring like gaskets (although they are not round) that are part of the VTEC Solenoid at the back of the motor. One is on the top of the solenoid under a plate, the other is between the solenoid and the engine block, where the solenoid attaches to the engine block. If you have a VTEC motor, these two gaskets almost surely are hard, have shrunk a little, are cracked because of the shrinkage, and are brittle. Cracks can be as wide as 1/8" - I have seen this on several old rubber O-ring like gaskets now. Oil will leak out of these cracks, and if the cracks are in a place where there is oil pressure involved (as there is with the VTEC solenoid), oil will come out faster. Even if you or the mechanic determine that these are not the source of your oil leak, I would strongly consider replacing them if I were you, because of the age of the car. They will eventually cause you problems, even if not now.

Buffalo.Rider

For our 2000 Honda Accord with the 2.3L VTEC engine, the HONDA part numbers for the two rubber O-ring like gaskets I mentioned above are:
36172-POA-005 (rubber gasket on the top of the VTEC solenoid)
15825-POA-015 (three-ring rubber gasket between the VTEC solenoid and the engine block.

Also from my notes, it looks like these two can be purchased at NAPA auto parts in a two-gasket kit, PN NOE-6000650.

If you do an Amazon.com search on this: "XtremeAmazing Upper & Lower Spool Valve VTEC Solenoid Gaskets for Honda 94-02 Accord 4cyl " or perhaps just on "VTEC Solenoid Gaskets", you will see what these two rubber gaskets look like.

MyUsernameName

my mechanic said it was the distributor o-ring. Hopefully that was it, going to drive it and will pay attention if it happens again.

Buffalo.Rider

If there is oil under/around your distributor, it can be the O-ring mating the distributor to the motor.
It could also be coming from inside the distributor. There is a seal - about the size of a quarter - that goes around the distributor shaft, that is inside the distributor.
These go out over time. The distributor will then leak oil inside it, and spill it out through a seep hole onto your motor.

If you have a 1999 model and intend to keep it for awhile, all the gaskets (and seals) I have mentioned in this thread will likely leak for you before too long and I think you would be well advised to replace them.
I would guess that all are old, brittle, hard, cracked - or in the case of a seal, worn out or nearly so.

MyUsernameName

Drove it for a few days an as of now the driver side is leaking a lot of oil to the point it’s leaving a trail on the street. At my mechanic shop now.

MyUsernameName

My oil pump seal popped out. They did an oil change and had to do the timing belt. Total cost was $314. $35 oil pump seal - $25 oil change. $250 labor.

Buffalo.Rider

If your 4-cylinder motor (on your '99) is the same as the one on our '00 Honda Accord (2.3L), then you have three seals behind the timing belt - a camshaft seal (on top), a crankshaft seal (on the bottom), and a balancer shaft seal (in the middle toward the front of the car). I think that what you are calling the 'oil pump seal' is the last of these three.

A word of caution on this seal - they have a reputation of popping out about 60K miles after a timing belt job. It happened to me. We were lucky, the trail of oil went into the driveway, so we caught it at home. There is a fix for the popping out ... a retainer to place over the seal so it cannot come out. They are available at NAPA, part number (per my records of a few years ago) ATM 058-2912.

If your mechanic did not put one of these retainers on, you might have this same problem in a couple of years.