[Ccraddock197]

Hello everyone,

I recently bought a low mileage 2001 Pathfinder 4x4 (140k). Before I bought it my mechanic took a look at it and said that it looked like it had a rear main seal leak. He told me it would need replaced within a year more than likely and it would be about a $1,000 repair

The Pathfinder was parked in the driveway and I noticed a small pool of oil. Maybe 8-10 drops leaving a 3” diameter pool once settled. I continued to monitor it and it stops after 8-10 drips once the engine is shut off. This seems a little more severe of a leak than when my mechanic looked at it. Right now the oil level is in the dead center of the dip stick

I’m willing to fork out the money to get the repair done because I knew this was a problem when buying the Pathfinder. I do have some questions though I’d like some advice on.

How long can I wait on this repair? I watch my oil level closely by default but more so with this problem.

What is a fair price for this repair (considering it’s 4x4)? Ive seen some people take theirs to a transmission shop and have the repair done for $600 and I’ve seen some posts where people take theirs to the dealer and pay $2,000.

Has anyone ever had any luck with an oil additive that is supposed to fix the leaks? I’m weary because I believe It to be snake oil, but it certainly would cost less than the RMS.

 

[VStar650CL]

Sealer will slow the leak and maybe hold off the repair, but it's basically platelets for your engine-blood and it speeds up caking in places that don't get constant oil flow, like the PCV passages in the VC's. Replacing the seal isn't rocket-science and any competent engine or tranny guy can do it, it's just a long, crappy job to get everything out of the way on a 4WD. The only real "trick" is making sure to mark the flywheel and keep the index gap where it belongs.

 

[Ccraddock197]

Sealer will slow the leak and maybe hold off the repair, but it's basically platelets for your engine-blood and it speeds up caking in places that don't get constant oil flow, like the PCV passages in the VC's. Replacing the seal isn't rocket-science and any competent engine or tranny guy can do it, it's just a long, crappy job to get everything out of the way on a 4WD. The only real "trick" is making sure to mark the flywheel and keep the index gap where it belongs.

What would I do without you, VStar! Thanks for the reply. I will probably run some additive in it just to buy some time, but I’m definitely actively looking for a repairman to tackle the job. I’ve got 2 people I’m planning on calling for quotes tomorrow.

Based on my description how bad of a leak is it? Would the rear main seal leak while driving?

 

[VStar650CL]

Based on my description how bad of a leak is it? Would the rear main seal leak while driving?

Happy to help as always. Rear mains pretty much only leak when you're driving, then drip when you park. It can make it very difficult to visually estimate the rate of loss through the seal. Watching the stick on a per-miles basis will give you a better idea.

 

[Ccraddock197]

Happy to help as always. Rear mains pretty much only leak when you're driving, then drip when you park. It can make it very difficult to visually estimate the rate of loss through the seal. Watching the stick on a per-miles basis will give you a better idea.

I did watch under the engine for about 5 minutes at idle and didn’t see a single drip while it idled. Once I shut it off I seen some dripping. I reckon thats from the oil leaking down to the pan. I guess seeing the small pool under the PF was a bit alarming. In any case I will monitor the oil level. Thanks!!

 

[VStar650CL]

That may be the upper pan, or a leak at the very back of the VC dripping down the bell seam. I'd put some UV dye in there and make sure you know where it's coming from.

 

[Ccraddock197]

That may be the upper pan, or a leak at the very back of the VC dripping down the bell seam. I'd put some UV dye in there and make sure you know where it's coming from.

I’ll have to look at that. Honestly that’s very possible because my mechanic just slid under it, saw some oil near the bell housing, and diagnosed it at a RMS. I’ll have to look at that tomorrow. I know there’s an upper and lower oil pan. What’s the best angle to inspect the upper pan?

 

[VStar650CL]

The upper pan seam is going to be hard to see up behind the cats. Do yourself a favor and don't guess, a bottle of dye and a cheap magic-glasses set is about $15. Then you'll either know exactly where the leak is or you'll know it's inside the bellhousing which limits it to the seal or upper pan.

 

[Ccraddock197]

The upper pan seam is going to be hard to see up behind the cats. Do yourself a favor and don't guess, a bottle of dye and a cheap magic-glasses set is about $15. Then you'll either know exactly where the leak is or you'll know it's inside the bellhousing which limits it to the seal or upper pan.

So, an update on the Pathfinder’s oil leak. I bought a bottle of oil leak stop this morning a put it in the warm engine. Then I cranked it up and let it run for about 10 minutes at idle. Not a single drop of oil. I then drove at low speeds (engine and ground speeds) around the farm checking on cows. I didn’t exceed 15 at any given point. Parked it again and checked for oil. Come back out to a dry piece of plywood.

I thought the additive solved the leak. Then I drove at regular road speeds reaching up to 60 mph at one point, park the car, and see oil dripping.

Now, I would think a rear main seal leak would throw oil anytime the engine is running. Also, given that I seem to only see oil after driving at road speeds I’m thinking it’s the upper oil pan and possibly valve covers leaking oil. Am I right in this thinking?

The oil seems to be coming from behind the engine, though. That’s why it seems like a rear main seal. I think I’ll take it to someone for them to diagnose it.

 

[VStar650CL]

Even if you let someone else do it, have them dye the oil, get the engine washed, drive it for a bit, then take it back and let them use the magic glasses on the lift. Nothing gets more expensive in a hurry than thinking you know the source of a leak and being wrong!

 

[Ccraddock197]

So, an update on the Pathfinder’s oil leak. I bought a bottle of oil leak stop this morning a put it in the warm engine. Then I cranked it up and let it run for about 10 minutes at idle. Not a single drop of oil. I then drove at low speeds (engine and ground speeds) around the farm checking on cows. I didn’t exceed 15 at any given point. Parked it again and checked for oil. Come back out to a dry piece of plywood.

I thought the additive solved the leak. Then I drove at regular road speeds reaching up to 60 mph at one point, park the car, and see oil dripping.

Now, I would think a rear main seal leak would throw oil anytime the engine is running. Also, given that I seem to only see oil after driving at road speeds I’m thinking it’s the upper oil pan and possibly valve covers leaking oil. Am I right in this thinking?

The oil seems to be coming from behind the engine, though. That’s why it seems like a rear main seal. I think I’ll take it to someone for them to diagnose it.

My mechanic I use for work had the following opinion:

Keep an eye on the oil and run it until there’s a major enough problem to warrant repair/replacement. With the age it’s a wonder the leaks are not worse. It leaves about 10 drip In the driveway. Likely that will equate to a quart or so every oil change. Engines don’t die because of an oil leak rather they die from too little oil. (As the ole’ s***box saying goes “if it’s leaking oil it’s got oil”.) Its also possible the leaks will become slower with more daily use as the oil will condition and maybe swell the seals.

He also said for the cost of the rear main seal alone that’s close to the cost of a new engine. Likely when the leaks are too bad or the engine goes it’s time for a new engine which will probably run $2,000-$2,500 installed which is a good portion of the rear main seal job cost alone.

Even if you let someone else do it, have them dye the oil, get the engine washed, drive it for a bit, then take it back and let them use the magic glasses on the lift. Nothing gets more expensive in a hurry than thinking you know the source of a leak and being wrong!

I reckon you’re right! I am going to keep a close eye on the oil for now. It’s a new vehicle to me. Once I have an idea of the rate of loss I’ll be more comfortable. I guess I’m in a bit of a rush and definitely shouldn’t be!

I will say, I called my mechanic and talked to him about the job. He said that on a vehicle as old as this one I’m likely better off dealing with the leak. That was his opinion. He claims that fixing one leak will only make others worse because of the global increase in oil pressure. He said I’m better off waiting until the leak is too bad it can’t hold oil and to put a new engine in it. Paying to work on the engine in it now is a waste of labor costs according to him. The labor is better spent replacing the engine. Although, if I’m sure it’s the valve covers I may try that job myself.

I’ve looked around and I can get an engine/harness/ECU for about $1000 delivered and I’ll always have the old one as a “donor”. $1,000 is the rear main seal job. If I were to replace all the seals on the existing engine it would be around $2,000 which is a hefty chunk towards a new-to-me engine which I would replace all the seals on before installation.

He also said to use some conditioners, seal swelling additives, or high mileage oil since his recommendation is to swap the engine. He also claims that in his experience full synthetic can cause leaks in these motors and to try and use conventional. Lastly, he said with more miles being put on it some of the leaks may lessen. Basically, he told me to bulletproof the engine as much as possible and be prepared for a replacement. I think it’s sound advice considering I can import a Japanese motor for $1,000-$1,200 delivered with <50k.

What’s your opinion, VStar? Is he just telling me that to get me to go to another shop so he doesn’t have to work on it?

 

[VStar650CL]

No, for a vehicle that age with an unknown service history, all of that is pretty much sound advice. Run it till it breaks or you're ready for a wholesale overhaul, whichever comes first. Maybe you'll get lucky and the leak is a VC, and maybe the engine will surprise you and outlive expectations. Both nice maybes if they happen, but if they don't, you won't be in a position of, "Why didn't anyone tell me that?"

 

[Ccraddock197]

No, for a vehicle that age with an unknown service history, all of that is pretty much sound advice. Run it till it breaks or you're ready for a wholesale overhaul, whichever comes first. Maybe you'll get lucky and the leak is a VC, and maybe the engine will surprise you and outlive expectations. Both nice maybes if they happen, but if they don't, you won't be in a position of, "Why didn't anyone tell me that?"

Very true. I believe it will last a while. Oil is clean and I opened up the filler cap while it was running and didn’t feel any “puffs” of air which I’ve been told can indicate blow by. I think keeping oil in it will be the key to the engine lasting.

I actually have all the service records. I have every oil change mileage recorded on the CarFax by a local shop and other records for transmission fluid change and shift solenoids at 100k. I know it’s been well maintained at least according to the records. I was very pleased to find out the transmission fluid/filter had been changed. It’s something a lot of car owners forget about or avoid.

 

[VStar650CL]

That's entirely different. If it's had excellent maintenance, I've seen some of those babies exceed 250K. No point in trashing it over bad seals, fix 'em up.

 

[Ccraddock197]

That's entirely different. If it's had excellent maintenance, I've seen some of those babies exceed 250K. No point in trashing it over bad seals, fix 'em up.

Maybe I will. I’d have to know the source of a oil leaks first which goes back to the UV dye.

However, it’s enticing to want to wait until the engine in it to die, should it die, and replace it with a <50k motor with 3 year/unlimited mile warranty. Before installation I’d replace all seals on the “new”
motor. It’s really a catch 22 situation. The engine in it now sits at 140,500 miles.

 

[VStar650CL]

Hmmmm, decisions, decisions.....

 

[Ccraddock197]

Hmmmm, decisions, decisions.....

Haha! That’s the truth! Kinda leaning towards replacing the motor when it dies considering the mileage difference. Plus, I’d have an engine warranty on a 20+ year old vehicle. That’s something others can’t say!

 

[IanH]

my 2003 developed oil leaks from tranfer case so put it in to local eagle transmission place they replaced both transfer case seals and front auto box seal. move on two years and it looks like a rear main leak. milage then about 160 k.
they quoted for new rear main seal, price seemed reasonable about 500 from memory.
They reported that the leak was between the crank cases. They replaced the main seal as planned, no sign that it was leaking.
Since fixing this was much bigger job they siliconed the joint and buttoned it up.
They were hopefull it would be ok.
so good news is this worked.
Then starter started not working when hot about year later.
since this was 4x4 starter is virtually inaccessible for me to do the job.
$400 later pick up car. Drive on way to San Antonio transmission lets go with lots of noise.
at 168 K in Temple Tx.
traded in for new pathfinder.

hope this helps. miss my 2003!

 

[Ccraddock197]

my 2003 developed oil leaks from tranfer case so put it in to local eagle transmission place they replaced both transfer case seals and front auto box seal. move on two years and it looks like a rear main leak. milage then about 160 k.
they quoted for new rear main seal, price seemed reasonable about 500 from memory.
They reported that the leak was between the crank cases. They replaced the main seal as planned, no sign that it was leaking.
Since fixing this was much bigger job they siliconed the joint and buttoned it up.
They were hopefull it would be ok.
so good news is this worked.
Then starter started not working when hot about year later.
since this was 4x4 starter is virtually inaccessible for me to do the job.
$400 later pick up car. Drive on way to San Antonio transmission lets go with lots of noise.
at 168 K in Temple Tx.
traded in for new pathfinder.

hope this helps. miss my 2003!

Thanks for the reply, IanH.

Ahh, sounds like some bad luck with your 03! When your engine oil leak occurred can you recall when the oil leaked out? Did it leak when idling or only after you had driven and parked?

I’ve got a few quotes for used Pathfinder 3.5 engines from sellers and it seems I can buy an engine with lesser miles than my current one for $800-$1000. All that would be left is an pay for an install after some “bulletproofing” (new seals). Given my case it seems like replacing the engine may be a better option as replacing seals may cause new leaks or existing leaks to worsen.

My transfer case looks good. Nice and dry all around the seals. No weeping and everything shifts nicely. I rarely use 4x4 but it’s nice to have even though we rarely need it in North Carolina!

 

[IanH]

The leaks resulted in patches on the concrete. I didnt check if it leaked while idling. In reality it wasn't that bad, just my DW objected to oil on the driveway or on the garage floor.
BTW I purchased at about 24k miles, 15 months old. It always used oil. 800 to 1500 miles to a quart. depending on how fast it was driven. Trips to San Antonio the speed limit is 80 mph around Austin, 85 mph to Seguin. 75 most of the way. And thats not speeding, I plead the fifth!
This was not leaks !