Weeping Oil Leak and Possible PCV Issue

On to the issues: I've been noticing for the past while that the oil pan shows a mostly-dry stain of oil and the area around the oil filter shows wet stain/dirt. The source of this oil seems to be from the spin-on filter seal, though I am not 100% sure of this. I lubricate the filter o-ring with fresh oil every oil change and I tighten it to hand tight, exactly as everyone would recommend. It is possible that there are small dirt particles that could be resisting the seal, but this leak appears to be a very slow weep. There is a small "forming droplet" on the bottom of the oil filter, which is what leads me to assume that the leak is coming from the filter itself. I will attach photos below of the filter, surrounding area, and oil pan stain.




The second issue I am curious of is a potential PCV issue. My last oil change ran about 500 miles over my usual 3000 mile interval, though those extra miles were low load and almost entirely highway driving. Due to the extremely cold temps, the oil catch can would not drain at the time of the oil change from congealed sludge at the bottom of the can. After the 250 mile drive back to Indianapolis, I noticed the car behaving strangely when being taken out of gear coming up to a stop: the RPM would drop below my normal idle of 830-850 RPM to around 750-780 and the AFR would be lean between 15.5 and 16.5 for a couple of seconds before it returned to normal idle. After receiving advice from Enki, African, and Matt in Shoutbox, I drained the catch can after driving to have heat in the system, and a considerable amount of fluid came out. This *mostly* fixed the idling down issue, but it would still dip down to about 790 for a very brief time when it would fall to idle, though there was no abnormal AFR condition after the can was drained.

Yesterday, when driving home from the grocery store, I passed someone with a small 4psi pull in second gear. Afterwards, the car stopped dipping into the 700s on idle down entirely, though I saw in my mirror that there was some white smoke/steam/something in my rear view mirror during the pull. It was about 43F outside, though I'm unsure if that is cold enough or if humidity/pressure conditions were enough to cause water vapor from the exhaust to be visible in that quantity. I then began to speculate: if there were enough oil in the lines to cause a PCV issue before, would the excess in the manifold side line not have been sucked into the manifold in boost? Could the smoke have been residual oil in the lines burning through the engine? My biggest fear is that if the PCV is clogged, that smoke could have been oil burning from blowby. I will attempt to open up the PCV system over the weekend, but I will have to be quick on Friday as the car has an alignment appointment on Saturday and I have to return to school on Sunday. There really isn't room for me to make errors and have the car down for longer than Friday. Any advice on either of these issues would be greatly appreciated. Thank you for your time if you read this far.

 

As far as finding your leak is concerned I would clean everything you can with brake clean and wipe it down as best you can so you have a clean surface to start with.

Depending on severity of the leak you can try dye in the oil or baby powder on the areas you think the leak could be coming from.

I had a one of the seals on the plug on my sandwich plate fail and it coated the bottom of the car in oil and was tough to see where the exact source was.

Scroll down to the bottom of page 1 on my build thread and you'll see what I'm talking about with baby powder. I did that all on jack stands, cleaned everything, tossed baby powder and then started the car and it quickly became obvious.

https://mazdaspeeds.org/index.php?threads/well-its-out.13831/

 

Thanks for the response! I will absolutely try that when I get back home this weekend. I have brake clean and baby powder available so it should be a simple way to find the source of the leak.

 

This is a good walk through on the dye method

 

Has the leak persisted through an oil change? If not maybe the filter just isn't made correctly

Have your battery and alternator load tested for the idling issue

 

are you sure it's not the oil cooler gasket on top of the oil filter housing? Mine was leaking and creating a similar area.

 

not terribly sure of anything at the moment, I can only hope everything will become a little bit clearer once I'm able to get the car in the air over the weekend and take a closer look at everything

It feels familiar, but I don't think I've ever seen it be this much or the stain be this dark. If at all in the past, it was just a very light stain around the area.

 

Update: source of leak confirmed to be the filter o-ring using baby powder method suggested by @Mtnbker3531
I sprayed down everything I could with brakleen and the top of the filter was the only place that showed leakage after starting the car. It seemed like a very slow, mild weep, but I’m reluctant to just leave it be until the next oil change. Is there really anything I can do to fix this short of just draining the oil and replacing the filter?

 

You can just replace the filter without draining your oil and then just top it off. You'll only lose what's in the filter and whatever is above the filter in the oil cooler it won't be a lot, maybe 1/2 qt max.

 

That’s a relief. I think I’ll just do that then. I’ve got a quart of pennzoil plat 5W-30 in the trunk, but it’s the “high mileage” version of the oil vs. the regular version I have in the engine. Is it safe to mix these? I assume it’s likely not.

 

You should be fine using the high mileage version to top off it's just a slightly different additive package.

I'll steer you towards this forum for any and all oil related research.

https://bobistheoilguy.com/forums/

 

Thanks man, I really appreciate all the help you've given me with this issue! Guess it's time to get a little casserole dish for the oil and a new filter. I'll be sure to wipe down the motor-side seal ring with a shop towel to clear away any debris that might have been obstructing the filter seal.

 

just a heads up, I replaced my seal on my oil cooler 1.5 years ago and the leak is back. The cooler was re-designed at some point (i assume to provide a better sealing surface.

My oil cooler is black and the revised one is silver.

This video talks about the gasket issue and the revised mazda part.



Link to revised unit on ebay:
Genuine MAZDA 3 5 6 CX-7 Updated Engine Oil Cooler Kit LF6W-14-700A LF9V-14-789 | eBay

BTW... called it!

 

He said it was the O-ring on the filter, not the O-ring on the oil cooler.

 

Whoops read that too fast!
Thanks

 

I'm glad you were able to find your leak. I learned that baby powder method from a friend of mine who is a Maserati/Ferrari mechanic.

The collective knowledge of this forum has made everything I've done to my Speed infinitely easier. That being said, at the very least I owe it to the forum to help out other members if I can, after all that's the point of this place.