Oil Leak Query - Oil Cooler O-Ring Vs. Oil Pan Gasket Leak
 

2002.5 Maxima. Taking a poll here: wondering which item fails more commonly than the other -- the O. cooler O ring or the O. pan gasket? Or... do they both fail past 100K? Thanks!

And the second question -- since this is a gen 5.5, do I need to replace the oil cooler o-ring with a 2003+ o-ring? For example,
And lastly... I notice from a lot of the threads that folks have a difficult time getting the replacement seal to hold oil after only a couple of weeks and it starts leaking all over again. Is there a thread that discusses this in detail and provides a solution? A better updated o-ring and or RTV sealant combination?

I just did both, they are very easy to do, I'd just do both if I were you, as you need to drain the oil to do either. Mine was leaking somewhat from both. I used RTV on the oil pan and the oil cooler gasket was $3 from eBay. I did it during this oil change, I'm at 194K

Which part number did you use to replace your o-ring?

i just did o-ring and it has been fine since. good 2-3 years ago

Upper oil gasket, there really isn't a lower, as it's just RTV. Mine began leaking like a sieve, and everything points to the RTV in between the steel pan though. Going to replace the RTV in between there and see what happens. In my research it seems as if the O ring goes most commonly but mine doesn't look as if it's coming from there. But the O-ring does seem like an easy fix, so if the RTV doesn't fix it, hello O-ring.


The O-ring is like 5$ from the dealer. PN from Nissan is, IIRC 21304-JA11A

https://maxima.org/forums/5th-genera...-pan-leak.html

See post #5. I list the two seals for the oil cooler. I used just a very thin layer of gasket maker on both sides when installing.

Both work. Mine has seen no further leaking. As mentioned, no need for gasket for oil pan, just liquid. You'll discover if its the pan once you remove the cooler.

Heads up, if you're doing Cattman headers, a 4th gen oil pan fits and empties toward the passenger side.

My car used to leak oil in the same area. Bought the O-ring from the local dealer, replaced it in about 10 mins and never had oil leaks since then.

Fel-Pro actually has a gasket for the steel pan. Amazon reviews look god too. :p