Hi,

First of all, I couldn't find a pathfinder forum, sorry if this is in the wrong place.

I just bought a 2002 Pathfinder 185,000 miles and it has 2 bad oil leaks. Just sitting cold, the engine leaked about 60ml overnight in 2 spots.

The one in the rear seems to be forming between the transmission (automatic) and the engine or the aluminum oil pan. This makes me think the leak is coming from the rear main seal or the upper oil pan gasket. I've attached a picture where you can see the bead of oil. If you look closely (on the right, next to the bolt) you can see a second bead. Above those beads is completely dry.

The other leak in the front, seems to be forming in what I think is the oil cooler. Whatever that component is, it's connected to the aluminum oil pan right next to the oil filter. I've attached a picture of this one too. This picture is looking up from the front. The area where this component connects to the oil pan seems clean as well. I think this device itself might need to be replaced.

My thought was to change the upper oil pan gasket and the rear main seal while in there. I was curious to get a quote and went to a mechanic that I was told was very honest and good. He told me that a car with this age and mileage, I shouldn't fix it. He said that the crankshaft moves whenever I push and release the throttle and within a few months, the leak would come back.

My questions are:

1. Do you think the upper oil pan gasket and rear main seal are the likely causes of the leaks?

2. What is that device in the picture that is towards the passenger side of the oil filter?

3. Do you think I should replace that device?

4. Do you think this mechanic is right that it would leak again really quick due to engine movement?

5. If that mechanic is right, is there anything I can do to fix this?

I'm not looking to give up on this car. I would like to fix it up and have it for several years.

Thanks.

Rear:


Front:

Yes there is a Pathfinder section on here, take another look when you get a chance.

You likely need to replace the o-ring gaskets in the oil cooler, fairly easy to do yourself and you can get the o-rings online on Ebay for around $15.
https://www.ebay.com/itm/NEW-2001-2004- ... HV&vxp=mtr

post6759440.html?hilit=oil%20cooler%20o ... s#p6759440

Can't really help with your other leak.

Thanks, I found this video which does look like exactly my problem for the front leak. I will try this in the next couple days.

https://www.youtube.com/watch?v=zyJcV_oSh58

Could a moderator please move this thread to the pathfinder forum of my other questions?

Moved to Pathfinder Forum.

I have a 2002 Pathfinder as well, with 200K miles on it. I had the same leaks and fixed them/had them fixed. To answer your questions:

1. Yes, IMO probably the rear main seal. I had the dealer fix mine as that repair is more than I can handle. They replaced the upper pan gasket as well, they told me they do that regardless on any rear main seal job since it's right there. I would suggest having both the rear main seal and upper pan gasket replaced if either is done.

2. That is the oil cooler.

3. It doesn't need to be replaced. There are two o-ring gaskets in it that need to get swapped out to fix the leak. I fixed mine in less than an hour, wasn't much more difficult of a job than an oil change.

4. I don't have enough knowledge or experience on these engines to contradict what your mechanic told you other than that's the first I've heard of that. I had mine repaired at 197K miles and at least 6 months ago and it has not leaked since. The dealer that did the job told me it was a fairly common issue but didn't say anything about the crank moving and it being a futile repair. I have a 12 month/12K mile warranty on the repair in any case. I'm inclined to think your mechanic is incorrect.

5. I think you should take it to another mechanic or two, including a dealer, and see what they have to say. If it is the rear main seal then replacing it is the only fix that I can see.

My Pathfinder is actually the vehicle that my daughter drives. I've fixed a lot of stuff on it but it seems to be pretty solid now. Short of a major component failure like the engine or transmission, I will be happy if we get at another 100K miles out of it.

Regarding the RMS leak, our 2003 PF my son got a year ago has it (130k mi). We knew this when we bought it, used it as a negotiation point, we were quoted $600 to repair from an indy shop (dealer quoted the seller $1300!). I tried Blue Devil and it slowed it, but just temporary. About 5 months ago I put a large heavy duty zip tie around the oil pan and tucked in a folded 8"X8" cotton rag to catch the drips. This has worked so well it doesn't leak at all for about a month so now we have no plans to fix the seal. Takes about 2 min to change out the rag.

For your oil cooler leak, that sounds easy. Be sure it is not your pass side valve cover leak though, as this is also common and it dribbles down to the same place as the cooler.

I replaced the oil cooler gasket and o-ring a few days ago. I haven't noticed any oil leaking around there since then. The rear leak is obviously still going though.

I did both of those seals when i rebuilt my motor last year.

First, I am an experienced A&P mechanic and the rear main seal was a total pain in my arse. I had to do it twice. first there is a front and rear lip seal that always get replaced when the oil pan is dropped. Second, the rear main seal is referred as "the devils seal" on 350Z forums. The lip on that seal will lip over, if you even mention how dirty its mother is or the weird shade of brown it is.
please let the dealer do this one.

The oil cooler orings were also a bit of a pain. with big hands the bolt that holds the 2 halves together is difficult to reach but doable. LUBE the s*** out of the orings cause they will want to roll and tear so be careful and make sure you torque that bolt on the higher end of the torque limit. At the lowest torque setting i was getting leakage still. After torquing to the higher amount the leak went away and its been about 15k miles.

850pathfinder wrote: ↑

Mon Jan 15, 2018 12:25 pm

I did both of those seals when i rebuilt my motor last year.

First, I am an experienced A&P mechanic and the rear main seal was a total pain in my arse. I had to do it twice. first there is a front and rear lip seal that always get replaced when the oil pan is dropped. Second, the rear main seal is referred as "the devils seal" on 350Z forums. The lip on that seal will lip over, if you even mention how dirty its mother is or the weird shade of brown it is.
please let the dealer do this one.

I've developed a very small leak at the RMS and I was wondering if you recall how many hours it took you to get it done.
Thanks!

No, it wont come back if you do the work properly. Yes I have done both of them. You have to lower the transmission and also lower the forward differential(if it is a 4x4), then you have to hold the engine with a crane on top(I fabricated a fixture to hold it) so you can remove the lower frame. The oil pan wont come out if you do not lower the frame that holds the engine. I had the time, tools and space and removed everything, including the whole front suspension which did it easier. I have videos but have never uploaded here. A shop will take anything like 1000 dollars, and some shops will charge lower but they wont remove this front frame, they will just remove the transmission and try to pull the oring and push the new one in to save time, which will make your mechanic prediction true as it will leak later if done this way. Properly done, removing the frame and holding the engine, no shop is going to charge 600 dollars, so be aware. You also have to remove the forward exhaust and the middle exhaust to lower the transmission. It is one of those jobs that should be done properly the first time so it last a long time. Time will vary according to your skills, tools, space available etc. If I do it again it will take me much less time, but it is a 8 to 16 hour job, depending on you. I did 2-3 hours a day and took like 5 days. Good luck.

While I'm in there, are there any other gaskets, o-rings or anything else I should replace? I'm happy to spend some extra money replacing any other small components to save hassle later.

QCtech wrote: ↑

Tue Jan 16, 2018 3:17 am

I have videos but have never uploaded here.

Have you ever uploaded anywhere else? Would you be willing to upload them somewhere (either public or just to me)?

Thanks.

As I prepare to replace my oil cooler o-rings today, I notice that the clearance at the bolt wont allow for a typical socket and ratchet, let alone my torque wrench, to get in there. How have you guys torqued to spec in tight spaces like this? Excuse to buy another tool? Open-ended torque wrench?

Crow's foot attachment to my torque wrench did the trick. Combined with about 1,200 1/8 turns of the bolt
Patience was my biggest help on this one. Other than the tiny working space, easy job.

Honestly, stuff like that I don't worry about torquing it to spec and just go by feel. I pay attention to the materials (steel, aluminum, etc) and the size of the bolt and make sure they are tight but not excessively so. Suspension & brake parts and other items where I have clear access with a torque wrench I will use one. Stuff like oil filters and oil pan drain plugs, spark plugs, etc I just go by feel and have never had any issues.

I just bought another QX4 (2003) and it has a Rear Main Seal leak. I'm having it replaced next week. I wanted to add my experience for anyone searching for information on the subject. My vehicle is 4wd with 135,000 miles. The independent shop (very reputable) quoted me $1,374.13 for the RMS, lower pan gasket, and torque converter seal. I'm going to have them add the upper pan gasket as well. It's $1,160 for labor (13 hours) and the rest is parts.

I was planning to do it myself, but it's more than I want to tackle right now.