So I recently noticed puddles when i leave parking spots...it doesn't leak when the car is off.



Can someone just please tell me that my drain plug is loose or I need a gasket? If not, where does it look like the leak is coming from?

when you leak oil, its always trouble, plus those motor already burn oil, so now you burn oil, and leak oil. it wont really leak when the car off since there is no pressure, but it could be a number of things, could be just an oil pan gasket, bad oil pan plug, or your crank seal. pull the passenger side wheel off and look if there is any oily spots behind your crank pulley.

just start by replaceing the oil pan that rust looks pretty bad...

i think is your oil pan no much trouble but when changing press attencion to the bolts they will break

speak english-i just got a headache



@ridinwitha35:
if there's nothing around the drainplug you gotta keep lookin-agree on that oilpan(might wanna grab a replacement). Start it up, see where its comin from, go from there and good luck.

Mine has the same leak. On mine appears the oil is leaking between the drain plug and pan due to some deformation of the oil pan's mating surface. It seems someone applied way too much force to the drain plug and bent the pan slightly (or I am wrong).

The leak slowly drips once the oil is warm, and is a negligible amount compared to the total oil quantity.

My plan is to replace the pan (I think I recall the 6th generation pans fit and have some advantage) and perform my own oil changes.

Oil pressure switch is right around that area and is also known to start leaking.

The part is ~$12.

Could also be the oil cooler o-ring leaking, mine did that at one point. On that section of the engine it could be a number of things.

Pan looks to be in rough shape I agree, I just replaced the lower on mine due to it leaking. Hanes manual claims there is no "gasket" for the pan, this is true from the factory I think as it is just RTV however a felpro gasket does exist. Mine took a hell of a lot of effort to get the pan off and I mangled a corner in the process so you may want to just get a replacement pan and gasket and call it good. The bolts do suck also, I ended up replacing them with some stainless hardware.

Here is a diagram of the oil cooler O ring that tends to leak, i have access to all data if you need anymore exploded views.

Professor, can you send me a detail on the oil pressure switch? That's where my mechanic believes my leak is.

don't want to sound useless, but that bolt looks pretty rusted. try just replacing that and getting a new gasket first and see if that fixes anything.

Col Ronson, not useless in the least. If the fix is as simple as replacing the bolt and/or gasket, I will be a happy man. If the pan is bad, I feel like the bolts will get stripped when I try to unfasten them (stripped/broken bolts are my worst nightmare...see my endlink thread!)

Professor, thanks for that O-ring view; I always though the O-rings almost required an overhaul...I guess it means replacing O-rings is semi-simple to do?

I guess it only leaks after the oil warms up or something cause I had the engine on for like 10 minutes idling yesterday and didn't see any leaking.

I do my oil changes myself (minus the first one)...only put about 5k miles on it since acquisition (now has 128k miles) but I'll look into an oil pan replacement soon & just keep a bottle of oil in the trunk...just spent like $600 on suspension/steering parts so I gotta calm my spending down for a while.

Welcome to my world. I feel like every day, another part goes...

djfrestyl here is a view of a 3.5, i dont know what you have , give me more info and i can help ya out.
The oil pressure switch is in the same general location on the 3.0 except it dont have the cooler.

I35 runs the VQ35, which is the 3.5L. I have the same car. Pretty much the same guts as the maxima.

If you need help ridinwitha35, i have the PDFs of the FSM as well specific to our car.

Yeah, that's pretty much why I post in this forum vs the I30/I35 forum!

I've got the FSM as well....I can reference that but can only get real answers from the forum. I'm a do-it-yourself-er as opposed to someone who knows a lot about cars.

I happened to check my oil level today (I always forget to check it before I start driving 'cause then I'd have to wait for it to settle down). I had to put in 1.5 quarts to get midway between L & H....guess that 800 mile trip I just had really emptied me out. I also drive 20 miles to work and always have an oil puddle when I leave....when will I ever own a car that has no problems....

you know on the bright side at least you know your car will be always running on fresh oil... haha

I had the exact same problem and fixed it myself 2 weeks ago:

It is your oil pan- they are a common problem with the 5th gen.
Buy an oil pan from the nissan dealer (mine was $130 CAD)
Buy an oil pan gasket from a part shop (nissan only uses silicone with no gasket I think this is the main cause of the problem)
Buy some silicone to seal the gasket.

You will need a small socket set to get all the bolts off or an angled wrench (one of the bolts is hiding behind another part)

Drain your oil and take of the oil filter.
Remove the oil pan. (be careful if you pry it off be gentle and do not damage the aluminum upper oil pan)
Use a razor blade to scrape away excess silicone from upper oil pan.
Lube up your gasket with silicone and bolt on the new oil pan.
Replace oil filter and make sure all bolts are tight.
Fill up with oil and your problem is solved. (It takes about 1hr 1-1/2hr tops)

Buy a Haynes repair manual for the full instructions and tightening sequence for the bolts. PM me and I can scan the page from the manual if you want.

Good luck

Thanks everyone...will be doing this...."soon".

What do you mean lube up your gasket?

I am looking to do this soon if I use a gasket why would i lube it with silicone?

Thanks

Oil pan gasket, Or could be Rear Main seal? goodluck man.

If the RMS was leaking it would be inbetween the trans and the block. even then it probley would just be the rubber half-moon seal. There is a half moon seal in the Front of the block though. Maybe that is what you are refering to..

But i would try the cheapest remedy first IE new oil pan gasket then oil pressure sending unit

Those 10 bolts for the oil pan are damn near $5/ea at Courtesy...an extra 50 bucks!

Lower oil pan & 3 bolts are on the way, will let you guys know how it goes. Hope to God none of the bolts break otherwise I'm SOL!

So, what's the general consensus about this approach, i.e. using an actual gasket rather than running a silicone bead?
Yes?
No?
Doesn't matter?

Use either or, not both.

So I tried replacing the lower pan today - no go. One bolt is severely rounded and rounded bolt head for me = un-take-offable.

On the other hand, I finally got a look under my car....there's oil all on the control arm...can an oil leak by the pan actually reach the passenger control arm??? Good news is that I've already got some control arms on the way. But I don't think I've found the source of my leak .

I suppose it's possible...are you sure it's not grease or another type of fluid?

The grayish bolts under the control arm has brown stuff that looks like oil. Not sure what other fluid that can be.

My pan is still in definite need of replacement (just gotta figure out a way to get the rounded bolt out without breaking it) but something tells me it won't fix the problem. There's oil all up in that area.

Could be axle grease? Don't discount the oil pressure switch either. Mine was leaking and my pan was perfect. $12 and 20 minutes to fix.

There are plenty of ways to remove rounded off bolts. Vice grips, bolt extractors, etc etc.

Was dark out last night so I'll take a closer look since I got some sunlight.

If the real leak is the oil pressure switch or the oil-cooler o-ring, it's all good...I think I can handle those jobs. But if it's something else...that'd be 'shop-work' vs DIY-work.

Don't know what it is with me but I've never managed to remove a rounded-off bolt...always ended up making it worse. Well I've let PB do it's thing overnight, hopefully when I go at it again, I'll get it.

I've had luck doing this on a strut tower bolt:
Get an open ended wrench 1mm smaller than the bolt size. Beat it onto the bolt using a hammer. The wrench will 'shave' the metal as it's hit onto the bolt. Then just remove as normal. But with an oil pan bolt, they're very small and soft so YMMV. I'd go with vice grips or the rounded bolt extractors.

A 10mm socket no longer "fits"

What I've tried:

- 3/8" socket...but that just rounds it more
- vise grip pliers...rounds it more
- PB treatment
- chiseling around the base of the head to remove rust flakes
- pounding a wrench onto it but once I turn, the wrench releases

And something tells me if I ever do get the head to start turning it's gonna break off from the body of the bolt.

At this point I'd get one of those socket heads that can remove rounded bolts.

Good news, I got the bolt out...my first successful non-standard bolt removal, lol. I ended up going to Sears to grab the Craftsman "Bolt-out" socket set...but they didn't work. The 10mm socket was too big and the 8mm was too small....I was able to hammer an 11/32" socket on it and get it out. It probably only worked cause these bolts don't need a lot of torque (only like 6-7 ft/lbs), but hey I'm happy.

Now I'm just waiting for my RTV to set so I can fully torque the new pan on...pics coming!

Cool. nice job.

ya I had to hammer to get a grip on a couple of bolts that were totally coroded and covered in rust... lol I still reused all of them for the new oil pan though

Just when things were goin good...I let the RTV set approx 10 minutes and attempted to torque the bolts down...82-94 in/lbs (6.8-7.8 ft/lbs)...first bolt broke....tightened it too much! Damn torque wrench probably isn't accurate below 10 ft/lbs. Anyways I just threw extra RTV in the hole .

So far, only oil leak I have is the stuff that dripped down from the valve cover since I always miss the oil hole when pouring! A long highway drive is the real test since I only would leak after driving.

Some shots I grabbed:


My main tools:



Old pan...you can see two distinct holes around this bolt hole (the one I had the problem trying to get out) that had disintegrated due to rust:



Other side, old pan:



The view after lower pan removed:




New pan

Cleaned off the upper pan rim:



RTV beaded on:



..and installed! Yeah, that bolt by the filter is really just a hole filled with RTV....and I was too lazy to fully take off the Nissan stickers on the pan.