Looking for Help - oil leaking out of air filter

[HeelToeHero]

Hi guys,
I'm currently at a track day and I've observed oil leaking out of my intake tube and wetting my air filter. I'm running the gt350 intake from power pack. Have you guys seen this before? My suspicion is the drivers side PCV there is 1 or 2 sustained long right hand turns.

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[NightmareMoon]

Yes. What year is the car?

 

[NightmareMoon]

Ok so if you still have the 15-17 the valve cover design has a flaw which only shows up when you’re really sending it.

After a sustained right it seems to build up oil in the drivers side PCV line and then you can blow a Spy Hunter style smoke screen if it goes through the engine. You’re getting it out the filter which is probably better but still not fun.

I dont know any trackside fixes (other than back off to 8/10ths in the offending right hand sweepers, which is probably enough to stop it) but later you can put on the GT500 aluminum valve covers and/or run a drivers side catch can. Apparently every other valve cover for the coyote doesnt do this nearly as easily, but without DI you’re looking at a GT350 or GT500 valve cover swap. I’d also do the catch can as insurance.

 

[HeelToeHero]

It is a 2017, that seems like my issue. Thanks for the response

 

[HeelToeHero]

I didn't see any more oil driving 300kms back home. The intake tube was dry so that must have been my issue. It's strange I haven't noticed it on other track days though this was the first time I had run this track.

Adding some useful references I found on trackmustangsonline for future reference and help if people pull up this thread:
https://trackmustangsonline.com/threads/blowin-blue-how-to-diagnose-cause.17687/
https://trackmustangsonline.com/thr...-my-2015-mustang-gt-on-the-road-course.18528/

 

[NightmareMoon]

For my car, I never had the issue until aero and better tires. Then at CotA i had to pull hard sustained right sweepers, brake hard into a fast left and accelerate out, and it would bow white smoke, misfire, and bog. It was sucking a lot of oil from the drivers PCV, and when checked, it was wet.

If I just lifted a bit between the right sweeper and the left if wouldnt blow smoke. Happened in two spots on track, both followed that same sequence.

I put on a pair of GT500 valve covers and a drivers side oil catch can but never repeated the experiment at that same track.

 

[HeelToeHero]

Luckily I wasn't blowing smoke that I noticed or friends noticed. My exhaust tips were much more sooty than usual though

 

[HeelToeHero]

Update on this:
I did install a driver's side catch can as a first pass at a fix. All 2025 there was zero oil, bone dry, with street driving.
Last weekend was my first track day since this became an issue. The can would quickly fill (after 3 or 4 laps). The second session they black flagged the group because i was blowing a lot of smoke. Shortening my sessions the rest of the day and staying in a higher gear seemed to resolve it and let me get through my day. GT500 valve covers are enroute so I suspect that will resolve this once and for all.

 

[WItoTX]

Update on this:
I did install a driver's side catch can as a first pass at a fix. All 2025 there was zero oil, bone dry, with street driving.
Last weekend was my first track day since this became an issue. The can would quickly fill (after 3 or 4 laps). The second session they black flagged the group because i was blowing a lot of smoke. Shortening my sessions the rest of the day and staying in a higher gear seemed to resolve it and let me get through my day. GT500 valve covers are enroute so I suspect that will resolve this once and for all.

I had this exact issue, although oddly for me, it was downhill braking zones into a tight turn, or high speed sweepers to the right. 3-4 laps, black flag. Drive at 8/10, no oil. Originally I was just going to install a massive catch can, but even that I was filling up half way in a 15 minute session.

The Gen 1 GT350 valve covers also suck. The baffling is terrible. I put the GT500 valve covers on, problem solved. Looks like the GT500 mimicked the Gen 1 GT350 valve cover design.

Since I did so much searching for comparisons, and never found a one to one photo of the GT500 valve cover next to the GT350 valve cover, here you go. I believe the GT350 valve cover for the Gen 1 is essentially the same as the GT valve cover. Regardless, the baffle in the GT500 is higher into the valve cover, and seals off much better around the spark plug tubes.

As for install. I highly recommend removing everything, even the battery and heat shield next to the battery. It makes that passenger side even easier. The main tedious thing is the dip stick tube. It has a really awkward removal process. But while you are in there, there are tons of videos of guys replacing the dipstick and tube with a more accessible tube that pokes out from under the STB.

 

[HeelToeHero]

Glad to hear that solved it for you too. I'm just waiting for them to arrive
Lmr has a pretty comprehensive video on this job out now which seems to cover all the items you flagged!

 

[WItoTX]

Yeah it's a super straight forward install. Lots of YT videos out there. They sure look nice when done!

Btw, I went to a UPR vented catch can too just for a bit more capacity and a bit more robust solution because you will still get oil. But multiple 20 min sessions should be zero issue at 10/10ths.

And I think it's Pilotgore who makes a 3D printed funnel that threads onto the the oil fill hole if your interested. Very nice product.

 

[HeelToeHero]

Yeah it's a super straight forward install. Lots of YT videos out there. They sure look nice when done!

Btw, I went to a UPR vented catch can too just for a bit more capacity and a bit more robust solution because you will still get oil. But multiple 20 min sessions should be zero issue at 10/10ths.

And I think it's Pilotgore who makes a 3D printed funnel that threads onto the the oil fill hole if your interested. Very nice product.

Thanks! The job doesn't look too difficult! It looked like a lot of rtv that lmr used but I'll take their word for it.
Interesting there will still be oil, I'll keep my catch can. As long as I can make it through a full 20min session I'd be happy. I never used to have this problem so I guess chalk it up to getting faster...
Good to know about the funnel. I actually have a printer so I could model my own funnel too

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