# Oil Cooler Leak



## yarzepol (Dec 26, 2009)

I have an small oil leak coming from the oil cooler on the block mount side. I reached behind the brass cylinder and could feel the oil coming from there.










I read some posts for older model pathfinders where the seals could be replaced to fix this problems. Called the dealer and was told...

"With your vehicle they don’t make a separate o’ring for the oil cooler. You would have to buy the complete oil cooler. I would have to order the part and it would take 2 business days. They also require a new stud as well. The total with tax would be $304.56."

Just wondering if anyone else has had this problem with the 2005 and was the only resolution to replace the whole oil cooler assembly.


Ray
2005 Pathinder SE 4WD


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## NALtech (Oct 30, 2009)

FYI, Next time you change the oil, have a 22mm or 24mm socket handy. Loosen the one big nut where the filter screws on, and try to look at the back side. It should be a orange/red O-ring. If so just go buy one for a maxima with a 3.5. I highly doubt it's one unit, it HAS to have something to seal it to the block.


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## yarzepol (Dec 26, 2009)

An oil change is overdue, but wanted to see what other possible options I could explore rather than buy a new oil cooler. Thanks for the suggestion. I will try this.


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## tmayo33 (Feb 15, 2011)

*cheap fix to leaking oil cooler*

I have a 2004 Titan and had a leak on the block side of the oil cooler. I was also told that they do not sell the o ring separate from the cooler and it would cost $400 for the part and $100 for the labor. My dad and I came up with a solution that seems to work very well. When you change the oil again remove the ring from the used oil filter. Remove both of the hoses from the oil cooler (make sure to have something handy to plug both hoses, or you will be bathed in anti-freeze). Remove the oil cooler (as noted in a previous post, using a 22mm or 24 mm). Remove the ring (red/orange) from the back of the cooler and replace it with the ring that you removed from the used oil filter. I found that the oil filter ring has the same inside diameter as the cooler's ring, but the filter's ring is about 30% thicker. Also, the ring from the filter has a smaller outside diameter, so there is room for the thicker ring to expand when compressed. This seems to have stopped the leak, I paid no extra money for the part, and it only took about 10 minutes to get the cooler off and back on again. Hope this works out for you as well as it did for me. I still can't believe that it worked. Guess I'll have to change my pseudo last name of Murphy for a few days!


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## SPEEDO (Jun 9, 2003)

yarzepol said:


> An oil change is overdue, but wanted to see what other possible options I could explore rather than buy a new oil cooler. Thanks for the suggestion. I will try this.


the oem part number(o-ring) is 21304-17F20 for a 05 PF, they run about $5 (online)
they did up-date the cooler which does require a new stud... you can find the cooler (pt#21305-EA21B) for about $234 and the stud (pt#21313-EA21B) for $15 online....


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