So I left the car turned off for 4 days, went for a 2hour drive to get the fluids going and everything.. when I come back I see this in my garage.. I believe to be this is oil. It hasn't leaked oil since June of 2015' and when I got my oil change last month from the shop I noticed that on the notes it said "oil leak" something along those lines... my previous oil changes between June of '2015 to today I never got that message in the notes so I thought he wasn't being real.. but I just find out that it is actually leaking oil again...150k miles..

June of '15 I replaced the

Timing chain covers
Both front and rear valve cover gaskets
Oil pan, o rings, new oil
New intake manifold gaskets
New oil pressure switch


What could it be that could leak oil? What are all the items I need to replace that are known to leak oil if the gaskets are bad? I might end up replacing majority of it if someone tells me what leaks oil.

 

Hey Josh. Can you show some pictures from underneath the car?

We might be able to figure it out from the underside.

 

It looks like it's leaking somewhere underneath between the engine and the intake manifold. It's kinda in the center, nowhere near where the timing chain was leaking when I had the leak. As the ac compressor drops water onto the cardboard it dries up and there's no oil.

But my other cardboard on the other hand, where it's a little more to the right from the ac compressor, Which is kinda in the center there is some oil stains on that cardboard

I can get some pics underneath

 

To locate leak origins, I've got a "blue painters tape", "twine" and "lead sinker" technique that's never let me down.

PM me if you'd like hear about it.

 

cam sensor, water pump, transmission seals where the 1/2 shaft axles go in, ps fluid hoses and their connections, oil filter, oil pressure switch

 

I recently found the rear main seal leaking on the 99 model (with the 95 engine) and the manual transmission gear shift rod seal is also leaking. I'll have my work cut out for me on that one.

I may tell myself that its really a British car until I can find time to deal with it.

 

It's way more convincing with a heavy British accent!

No fun, especially if you don't have a lift handy in your garage (that's full anyway) LOL

Josh, nothing is better than getting it up on ramps or whatever, with a good light and search it out. Gravity deceives us sometimes and it runs a declined horizontal length before it drops.

Hopefully, you have an "Easy" button you can push before you look. I like those kind of surprises! Good luck!

 

Here are some pics underneath it.. on one of the side cardboard, I was able to catch some oil on the smaller one, the bigger coardboard was covered in water from the a/c until it dried up and the smaller one had a little bit of water but most importantly catch the oil

 

Driver side... my catalytic converter looks like it's shot.. lol but it still operates!

 

Remember some of the oil was maybe from when I had the car and it leaked oil for 2years until it got really bad and fixed it in June of 2015. So that's why it may look a bit oily..

 

I also this year want to clean up and detail the engine bay to nearly new or atleast better than what it is right now cause it can look a little cleaner, underneath to make it look nearly new, get rid of alot of old nasty stains, dirt, etc and also to find leaks much easier..

Kinda like CS AR and turbolink.. heh heh, that'll be a lot of work.. though the wizard, he has an crazy engine bay that I'll probably never get to lol.

I want to help out with my original exhaust system, as it looks like it's not letting air flow it could potentially give if I were to upgrade majority of the exhaust system as it does look like its shot and sorta rusty... the car does run smooth, but I may not feel the power loss from having the original exhaust system.

 

Morning Josh - Do you know if the upper oil pan "half moon" gaskets were replaced?

One way to tell this is to look at the front of the engine just under the crankshaft to see the condition of the "half moon" gasket.

Not directly related, it look like you may be losing some grease from the driver side CV axle. If you catch it in time, all it takes is a new OEM outer boot to solve that problem.

 

I believe if I got an new oil pan I'm sure would replace the half moon
gaskets.. not 100% sure on that.

What does losing grease do from the CV axle? And how much are the outer boots?

 

There is the black metal "lower oil pan, then there is an upper oil pan where the "half moon" gaskets mate up.

Here's a picture of the bottom of an upper oil pan. There is an access plate that covers the square hole at the back of the pan by the flywheel.

If you see oil dripping from the bottom of that black metal access plate, that usually indicates a leak from the rear "half moon" or Rear Main Seal (RMS) or both. Unfortunately, it takes transmission removal to replace the RMS. The upper oil pan half moons can be replaced by just removing the upper oil pan. Though removing the upper oil pan it is a lot of work, its just not as much as the RMS.




Here's a picture of the front "half moon" after a the upper oil pan was installed.



Here's a picture of an old front half moon below.



Turbobink has some great pictures of his engine when the upper oil pan and RMS was replaced.

Here's a picture of where the rear "half moon" gasket lives at the rear of the upper oil pan.

 

I'm actually chasing a little drip myself.

I was confident (and I still am) that my oil pressure sender was seeping ... replaced that and included some thread sealant.

Then I found that my oil drain plug of all things was a culprit ... fixed that.

Now a drip is still present.

It still might be the OPS, and I've yet to get the car off the floor but it might also be something else/more.

Just saying ... I feel you bro.

 

Crawl under and get us some closeups ! Cs_ar's cleanliness is unobtanium thats quite a leak youve got Josh. Definitely needs immediate attention.

 

I'm going to have to look a little more where its coming from, since I have not driven it yet after these pics, it hasn't leaked any on the floor so.. I have to see if its leaking when running or when its turned off for a couple hours after a drive. I'm pretty positive its not when running and it just leaks after the car is off.

I don't consider this a major leak pixelporsche, though I have to see how much its leaking.. cause I just now started to notice about it.

 

^^^ I'm NOT being judgmental or righteous at all but honestly, I've found anyway, that many times after a leak fix (or even after a messing fluid change) drips will persist simply due to an incomplete cleanup.

Not sure what you're weather is like right now, but I'd encourage you to do a real good cleanup of the areas you think might be the sources and those surrounding area for that matter to ensure your drip isn't just cling-on.

I've found that blue Dawn and a round long handle toilet brush work quire well.

This stuff works very well on motor oil and is what I use after every oil change. And it leaves your engine compartment with a fresh spring-time scent.

 

I thought it was a puddle overnight. To be honest if its not pouring on exhaust components it takes me a while to get around to it

 

Ok I found where the leak is coming from, I got good pics.. one of them is coming from the near the passenger side wheel, and one is coming from in between the two front wheels, where the splash Gaurds are at.. take a look.

On the very first few pics it may of looked like it was leaking in the front, but I see one leak on passenger side and one on the drivers which makes sense, cause when I took that picture of the garage floor, the passenger side was oily and the driver side as well where I parked the car.. also the one in the middle was some old oil I believe.. it wasn't oily when I touched it.

As you can tell the one in the middle looks much darker and dried up than the ones on the left and right sides where it looks like brand new oil, which looks more clear brown and wet. To my understanding what my cardboard has collected.. Its correct to be leaking from those two areas..

 

Leak by passenger side wheel. Looks like by oil pan? The cardboards are where it leaked, one of them was soaked in water from the a/c condenser until it dried and left the oil stain remaining.

 

Splash guards leak? More towards on driver side wheel than passenger, a little in between both wheels.. embarrassing to see so much oil.. but then again was probably when I had a really bad leak 2years ago until I fixed it.. so it's even harder to find where it is coming from.. should I clean all that nasty oil? It would look better..

 

Josh, I see oil on the wire below the oil filter.

Just by chance, was the oil changed shortly before the leaking occurred?

The reason I ask, is that is common for the old filter to drip over the wire as it is being removed.

Oil can start leaking in one area, then drip elsewhere. Either due to gravity, or the the breeze created by dricing the car.

 

Well when I got my oil change a month ago, I was noted "engine oil leak" from the shop. So I think it was leaking before (never saw a wet oil spot in my garage before I went) I got the oil change since my last oil change before last month was probably back in April of last year.

But it never leaked at all until last month probably. So I was confused about that.. maybe it was leaking for a couple days or so before the oil change?
Cause I did notice some freshly new oil in the spots I parked but some of them looked like a week old or just a couple hours old. So I'm sure shortly before the oil change it started leaking.

So what are u trying to say by the old filter to drip over the wire as it's being removed? And oil leaking one area and then drip elsewhere due to gravity?

 

Agreed. Or it could be the oil pressure switch which is very close by.

 

Josh, the oil filter is mounted side ways.
Oil will drip out of it as it is being removed.
It's unavoidable. Oil will drip right on to the wiring harness you took a photo of.

Wizard has a good point as well. Oil pressure sensors can leak as well. So it is indeed possible that the leak was from the oil pressure sensor, and noticed by the oil change guys.

It's likely a cheap fix.

 

Well I parked in a clean parking spot where there wasn't too much stains on the ground, left the car there for 7hours and when I came back.
I checked underneath it.. I could see two small drips freshly wet oil (I even touched it to see if it would go onto my finger) on the ground on the passenger side wheel where the oil filter is. Also where the driver side I assumed that it was leaking from there..but couldn't find any oil from that area.. so I guess its only coming from the passenger side.

If its the oil pressure sensor switch, how much am I looking at? and how long? Where is it located? What needs to be removed in order to get to that switch?

found a video of it.. seems to be right behind the oil pan. Doesn't look too hard. Looks easy.

 

If it isn't too troublesome, wait until after you change the oil to see if it stops. Oil filter seals aren't always perfect or sometimes not tightened enough. Unless you did the oil change yourself and know for sure it's tight.

Leaks make me insane! Especially ambiguous leaks that are somewhat evasive.

 

Well if I wait for the next oil change.. that'll be in May lol

 

Well, it was worth a shot! LOL

Best of luck! When you know for sure, it will be such a relief.

The bottom of your Maxima looks so much nicer than mine! Up here on Long Island, between the snow/salt and living near the ocean, you wouldn't believe the difference.

I haz jealous!

 

What does the bottom of your maxima look like since u live in the snow/salt? I could imagine over the years. I never had snow here.

Bleh I mean it could be better lol, It is just very dirty with all the nasty oil buildup stains.. There is no rust at all.. so thats one thing, that splash guard is hanging off.. I need to zip-tie it to something so it doesn't look like something is about to fall off.

 

What has been seen, can't be unseen....... It's Fugly!.......

 

Doesn't look too bad

 

Ok here are the list of leaks!

Oil pressure switch- Needs immediate replacing as it is under pressure and will only worsen over time

Front and rear crankshaft seals leaking, may need new belts in the process

Rear valve cover gaskets (Just a little leak, not dripping to the ground) Replaced it about a year and a half ago

Rear main seal leak! not too bad, but is leaking. Big job right here

A/c compressor is leaking oil (told to not to worry about it unless only warm air comes out from the a/c.. which I have never experienced yet.)


Power steering pump and return hose is leaking.. 2nd biggest job on this list.

Passenger/driver CV axle boots are torn and leaking grease

All the current leaks I have on this car.. Interesting.

 

Looks like I'll be tackling the Oil pressure switch and the front/rear crankshaft seals, replace the belts and see how much its leaking afterwards from there. Two leaks down, therefor less leaks as it looks like these two are the main leaks as of now.

 

Cut it some slack.

It is 17 to 22 years old after all.

 

Well I was being sarcastic on that quote turbolink lol.

It is just good to know all the leaks I currently have.

 

Well the oil pressure switch was replaced and cleaned a bit around the area. Also zip tied some splash shield areas that were hanging off. Makes a difference not seeing those dumb shields hanging off.

Also the front crankshaft seal and the two belts that were cracked and old have been replaced. I have postponed the rear crankshaft.. which is the rear main seal. Big job there so I'm gonna hold off on that one.

 

 

Noticed a very small amount of oil fall to the ground overnight. Think the oil has to settle. But defiantly better than it was last time. Got to give it a couple days/week to confirm it's still leaking some to the ground. Cause I am still currently still testing with cardboard boxes and without. .

But just not as much. To my confirmation is that it's leaking onto the ground in that area, no where else and only found fresh oil in that spot.

If then it has to be the rear main seal (crankshaft) that is dripping onto the ground. Cause it's directly underneath where the oil switch/pan is.