Nissan Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter #1
Hey guys so I have a 97 Pathfinder 4x4 v6 with automatic transmission and 175,000 miles. I have a oil leak that I believe it’s a rear main seal leak because the oil primarily drips from between the transmission bell housing and engine.

However, I am skeptical because you can clearly see oil around filter and oil pan in front and back. You also see it by the plastic guard under the vehicle by the sway bar. So I am not really sure where it’s coming from. But the actually dripping of oil is between the transmission and engine.

If I park downslope in my driveway after driving the oil will leak out about 7 drops and then it will stop. If parked upslope only and drop or two would come out. If parked flat I notice some drips by the next day.

I have had the transmission pulled about 4 years ago to replace the planetary gear and had asked them to replace rear main seal. And I do not recall seeing a leak after that. This leak started about two and a half years ago.

I don’t really tap up oil often. It’s been two months and 1300 miles and oil is at correct full level on dipstick.

Any ideas? Thanks.
 

·
Sup Mod keeping the peace
Joined
·
6,791 Posts
Verify whether the dripping fluid is motor oil or A/T fluid; in either case the tranny needs to be removed for the fix. It would be a sizable expense to just fix a minor drip. If it's not troubling you, IMO, I'd just live with it considering that it's a 23 year old vehicle and it's got 175,000 mi on it.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #3
Verify whether the dripping fluid is motor oil or A/T fluid; in either case the tranny needs to be removed for the fix. It would be a sizable expense to just fix a minor drip. If it's not troubling you, IMO, I'd just live with it considering that it's a 23 year old vehicle and it's got 175,000 mi on it.
Yeah it is motor oil. No transmission leaks. The weird thing is that it drips here and there when parked flat. And leaks out more when downslope in driveway then stops. But when it leaks out downslope is when I turn off engine. Does not leak when engine on. That’s what I’m stumped on.

I see residual oil elsewhere under there such as around oil pan and the back of the plastic skid guard. That makes me wonder if the oil leak is coming from oil pan and not rear main seal.
 

·
Sup Mod keeping the peace
Joined
·
6,791 Posts
It's possible that a valve cover gasket is leaking and the oil runs down the back of the block. You'll have to jack the car up and wipe the areas clean then watch it over some period of time to see where the oil is coming from.
 

·
Registered
Joined
·
12 Posts
Yeah it is motor oil. No transmission leaks. The weird thing is that it drips here and there when parked flat. And leaks out more when downslope in driveway then stops. But when it leaks out downslope is when I turn off engine. Does not leak when engine on. That’s what I’m stumped on.

I see residual oil elsewhere under there such as around oil pan and the back of the plastic skid guard. That makes me wonder if the oil leak is coming from oil pan and not rear main seal.
Crawl under and check pan bolts 1st...also Cam covers...try simple stuff 1st before you get too deep...just trying to help...
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
9,767 Posts
A common place for leaks in that area, besides the rear main seal, is the oil pan gasket's rear lip seal. If you part downhill and it stops but it will leak when you park uphill, it's probably the oil pan gasket. If it leaks most when the engine is running on flat ground, that's typically an indication of a rear main seal leak. Valve cover gaskets and oil pressure switches are also common oil leaks on these engines.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #7
It's possible that a valve cover gasket is leaking and the oil runs down the back of the block. You'll have to jack the car up and wipe the areas clean then watch it over some period of time to see where the oil is coming from.
I checked on the valve cover you mentioned, and I noticed the passenger side valve cover has residual oil around that area. However, the oil is not directly on the lip seal, but is just below the seal joint. In the area where the spark plugs screw in. This is on the side neighboring the plenum. On the other side of this valve cover there is some oil residue on the lip seal.

The driver side valve cover has no oil leak. That was replaced years back.

And this oil leak I am having only occurs when you turn off the engine and comes out between engine and transmission. Drips couple times then stops. A drip here and there afterwards. No oil leak when engine is on.
 

·
Sup Mod keeping the peace
Joined
·
6,791 Posts
From looking at the pictures, it looks like the back part of the valve cover is a little wet. When your vehicle is idling for some amount of time prior to shut off, high vacuum levels will cause the oil to pool up around the top of the head in the valve cover area but drains down immediately due to PCV action; so as soon you shut off the engine, this pool of oil will leak out through a break in the gasket during a short period until the oil has a chance to drain down into the crankcase. That's why you have those drips for a short time.
 

·
Registered
Joined
·
4,186 Posts
Verify whether the dripping fluid is motor oil or A/T fluid; in either case the tranny needs to be removed for the fix. It would be a sizable expense to just fix a minor drip. If it's not troubling you, IMO, I'd just live with it considering that it's a 23 year old vehicle and it's got 175,000 mi on it.
I had transmission/ transfer case leaks and Oil from joint to Engine.
Had Transmission and transfer case pulled, all three seals replaced and new rear main. They said rear main was ok, it was gasket between sub pan. dont remember correct name. They replaced main seal and covered leaking gasket with sealer. It worked.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #11
I had transmission/ transfer case leaks and Oil from joint to Engine.
Had Transmission and transfer case pulled, all three seals replaced and new rear main. They said rear main was ok, it was gasket between sub pan. dont remember correct name. They replaced main seal and covered leaking gasket with sealer. It worked.
Yeah I had my RMS replaced a few years back when I had transmission dropped to fix a part. I have no transmission/transfer case leaks though. Just this minor oil leak.

I am not too sure about which gasket you're speaking of though?
 

·
Registered
Joined
·
24 Posts
Discussion Starter #12
From looking at the pictures, it looks like the back part of the valve cover is a little wet. When your vehicle is idling for some amount of time prior to shut off, high vacuum levels will cause the oil to pool up around the top of the head in the valve cover area but drains down immediately due to PCV action; so as soon you shut off the engine, this pool of oil will leak out through a break in the gasket during a short period until the oil has a chance to drain down into the crankcase. That's why you have those drips for a short time.
Thanks rogoman, I'm going to replace this passenger valve cover gasket soon. Should I try to get back a nissan gasket or aftermarket? And should I used any sealant?
 

·
Sup Mod keeping the peace
Joined
·
6,791 Posts
Nissan gaskets are good. I've been using FelPro gaskets for years with good results. IMO, both are good; it's your choice. I always use "Permatex Copper Spray-A-Gasket Hi-Temp Adhesive Sealant" on most gaskets; never had a leak. Hang the gasket on a nail and spray it on both sides; let it hang for about 1 min, then install.
 

·
NF Mod/Nissan Master Tech
2006 Pathfinder LE, 2003 Frontier SVE
Joined
·
9,767 Posts
I wouldn't use Copper spray gasket on VG valve cover gaskets. Copper spray gasket is great for paper or metal shim gaskets, but not really for rubber, EDPM or silicone gaskets. Most of the name brand, aftermarket gaskets, i.e. FelPro, Mahle, Victor Reinz, are fine, but I recommend you get a valve cover gasket set that comes with the grommets, too, such as FelPro # VS50251R1 or Victor Reinz # 151094301. All you need for the gasket is a clean surface. The valve cover has bendable, metal tabs that hold the gasket to the valve cover and keep it in place as you re-install the cover to the head.
 
1 - 14 of 14 Posts
Top