Hey Guys,

Having troubles with my oil filter. Usually this would never make it to a forum post but I'm out of ideas. Hoping there's something stupid that I'm missing that will help me stop leaking.

CAR Setup: 08 350z - Basically stock motor with intake, HFC's, exhaust, and Stillen oil cooler.

Previous owner of the car said to use Mobil M1-107 oil filter or equivalent.

Stillen site says to use FRAM PH3950 with their sandwich plate.

Because of the discrepancy I just bought both my last oil change. The FRAM option DOES NOT fit the threads.

I went with the Mobil filter that seemed to fit fine, threaded on fine, gasket sat right in the middle of the surface of the sandwich plate, and the filter is about as tight as I've ever put an oil filter on - I still have a small leak.

Gasket surface is squeaky clean - no debris, burrs or damage that I can see or feel.

I've done maybe 200 oil changes in my life - and I've never had a filter that kept leaking like this. I thought it may be a bad filter so I bought another one and installed it - same thing.

Can the sandwich plate be warped? How would I check this?

In all my research I can't find any sandwich plate for a Z that recommends the m1-107 filter - Maybe the old owner gave me the wrong number by mistake? It's possible the cooler is stillen and the sandwich plate is another brand but I see no branding on it. Maybe there was an older stillen model that used a different filter?

I'm taking it to the track next weekend and really want to fix this before I go. The leak is so minimal (literally 1 drop on my garage floor overnight) that I am not that worried about it, but I hate any leak at all... like most of us probably.

Yes I am positive this leak is coming from the oil filter and not somewhere else. You can watch the slight drip form along the gasket and there is no oil above the filter dripping down.

Ideas anyone?

Sorry for the wordy post I wanted to give background on the issue.

 

He gave you the wrong filter number...use M1-108. That's what I use; I have an 07 no leaks. Hope it solves your issue.

 

Are you running a stillen oil cooler too?

 

The M1-108 should still fit, shouldn't it?

 

+1 M1-108 is the one you want. I have an '08 myself and use that exact filter every time. No leaks so far.

 

That is my question - haha.

So the M1-108 and m1-105 have the same thread size. The m1-105 is cross comparable to the fram 3950 which does not fit (but was the one recommended by stillen to fit their sandwich plates, so by that reasoning the 108 won't fit either...

I'll go to pep boys on my lunch and see what looks good. Maybe I'll buy one of each again and check this all out. I was just hoping there was an easy solution somewhere.

 

Are you running a stillen oil cooler too?

 

Don't have an aftermarket oil cooler on my '08, but have been using the Mobil1 M1-110 since the car was new. Larger filter, same threads, of course. I discovered it because my wife's Acura TL-S uses it.

 

Stupid question, but you are oiling up the rubber gasket on the filter before installing it right? =D

Otherwise, the only other thing I could think of is a warped surface on the sandwich plate or possibly too much oil pressure. Is your PCV system breathing correctly? What kind of oil are you using?

 

Yes I'm oiling the gasket before install. Good question though I wish that were the issue.

Oil pressure seems normal, and because it will leak at idle. when oil pressure is around 30 I don't think it's oil pressure related. It doesn't get notably worse at higher oil pressure though, still the same 1 drop on my garage floor no matter how much or hard I drive.

Using Castrol 5w30 synthetic

I have not checked into PCV issues. I guess I could clean the valve?

EDIT: Any idea on best method to measure flatness of the sandwich plate?

 

The simplest method would be a straight edge and a flash light. At least that way you could see if there are any "major" imperfections. I'm assuming the plate isn't scratched/pitted where the seal makes contact.

 

Nothing I can see or feel with my fingers. Ruler + flashlight is a simple idea, probably wouldn't have come up with that thanks.

I think I'm gonna hit it with brake cleaner and scrub it good then get up close with a flashlight and see if I am missing something. Maybe a hairline crack or something?

 

There is an oil cooler "plate" sandwiched between the block and the oil filter.
This has an O ring between the block and plate. It is held in place by the bolt that the oil filter spins on. If the bolt is loose or the o ring is damaged it will cause a leak that appears to be coming from the bottom of the filter. Look at service manual sheet LU-10. An easy fix if this is your problem.
This was my problem with my 03 350Z

 

I'm not. I guess that's what I get for skimming through your info. Disregard my advice as it is irrevelant. Again, I hope your issue gets solved soon.

 

^^ Wow really? I'll give that a glance tomorrow.

If that's the answer I owe you blu. Saving my *** here I'm trying not to get frustrated but it's been a pretty annoying issue, even if minor.

Looks like I would want to pick up #4 off this diagram right? Or is the gasket you are referring to something that corresponds to my specific sandwich plate?

 

All good man, I know I wrote a lot of BS up there so I don't expect everyone to read through it all.

 

I had a similar issue on a prior car. My guess would be this is the culprit. Its not hard to loosen the threaded "nut" that the filter screws onto when your taking it off, just be careful re installing the small o ring gasket.

You may even be able to get away just checking the threaded nut to make sure its snug, it may just need to be tightened a small amount without having to un and re install it, but thats an easy enough job anyways.

IIRC my sandwich plate gasket i ended up using the prior gasket from the last oil filter i used. I would switch it out ever few oil changes or more with the prior filters gasket.

 

Wait like... you peeled the gasket off your oil filter to use it on the sandwich plate?

 

Its been years since i messed with that car but i am almost positive thats what i did. Your sandwich plate MAY be different so take it with a grain of salt. I cant see why it would be any different though...

 

Yeah, but I'm not sure I'd want to use an old gasket which has gotten hard and may be prone to leaking. Maybe buy a cheap filter, just to throw away and use its gasket, or find a source fr just the proper square-cut o-ring you need.