My brother has a 99 accord EX v6. We were checking out his car when he noticed a spot behind the engine semi filled with oil where it appears something could or should be bolted. I've looked a bunch through the service manual and honda parts sites, trying to match up the area or potential part with a diagram. So far the only luck I've had learning more is by searching for matching transmissions then browsing through the photos available. Some seem to have this cap and a few others seems to have a sensor(but still unknown) installed there. If circled the area in yellow in the attached photos. Any help or guidance regarding this would be appreciated.

 

Are you comparing a JDM to a US transmission? You'd have to look at the same transmission because they would be different in the 2 countries and you would change the difference if you bought a JDM for a US car.

 

It should be a stock USDM transmission. As far as I'm aware at least. I don't know if the pictures I posted were usdm or jdm, I found them simply searching by the tranny designation that I believe to be b7xa.

Currently the area circled in red in the below picture, on his car is filled with oil that has leaked from what I believe to be the valve cover, however upon seeing the type of "hole" it was in, it raised concerns about wether or not there is
1)something missing from his car
2)contamination of trans if there is no seal there but should be
3)just knowing what its for so I can select the appropriate replacement if applicable otherwise one of those "caps" shown in one of the examples from the first post. Il try to get a picture of his actual transmission when he gets home later


edit:for clarity, its like a little inch deep pool of oil inside the large circular opening circled in red in the picture above

 

In that location for Honda Odysseys, that is where there is either the older style Vehicle Speed Sensor (VSS) (Honda Part No.: 78410-SV4-003) or the torque converter cap (Honda Part No.: 23811-P8F-000). Only certain Odyssey models had the old style VSS.

Honda Accord A/T 6th generation didn't have the older style VSS. The Honda parts diagrams also didn't list the torque converter cap (essentially a plug).

 

So that would mean it is fine if it looks like the last picture I posted? No chance of contaminating tranny with nothing there? I wasn't able to see the bottom of the hole when I was there but I dipped my screwdriver into the oil that had filled up and it went down id say just shy of an inch.
also thank you for your answer that is exactly the information I was looking for.

 

On the Accord, it should not be an issue with debris going into the transmission at that area.

 

Do you know if the transmission on your brother's Accord is the original?

 

It sure doesn't seem like it's OK to have an open hole there. If it's where a VSS would install, that will be open to the final drive & differential. Maybe the Accord parts list doesn't have a plug because it's permanently covered, and this transmission isn't original to the car.

 

Late answer but have finally got to check it out again and after cleaning what I could from the hole it does not appear to lead anywhere, it basically looks like a blind hole that's been machined but as far as I could tell it doesn't appear to lead anywhere. Odd that the bolt holes alongside it are threaded for what I would assume be the mounting of an above mentioned VSS in some oddeseys. Am I correct to assume any VSS for these transmissions are the vertical pin type? Meaning any hole through the case would be in the center of the bore, similar to 4 cylinder VSS in the 5th gen accords?

Thanks for all the knowledge and help! I do appreciate it.

 

I don't really know the answer, but it seems reasonable that the rough casting would be the same across many cars, but some of the finish machining is different. Like they don't drill the final hole through the case when it's destined to be installed in a car that doesn't have a VSS there. Newer model-years might use the ABS sensors instead of a VSS on the transmission?? But I thought that didn't start until later than 1999...?
So does the speedometer & cruise-control work on your brother's car? I've got a shop manual for 1998-2002 but it does not include any V6 stuff.

Probably the oil came from an oil leak somewhere nearby since the hole doesn't go through the case.