Post your latest oil change
- Thread starter Superbuick96
- Start date
I'm tossing that nasty juice. Water, fuel, burned goodies!>> Sample sent off to Blackstone
Why? It's just oil...so 20 min track session come in and drain it back in...I mean it's litterally what was just in the crankcase 20 min before. Clearly overnight if I get condensation/coffee colored stuff I pitch it...
Same crap that's in your crankcase every time you drive it that you don't worry about. I think you have to understand that this is after track use so every 20 minute session I come in it's got a handful of ounces in it I just drain them back in this isn't like over 6 months or something like that where you would have a lot of water condensation mixed and sure I'd pitch that too. I don't collect anything in it during normal day to day driving.
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I guess I could make a video of me dumping it back in and my clickbait title for my YT channel would be "I DID SOMETHING TO MY CAR TODAY AND IT WAS DISGUSTING!"
And will show me the same thing every other one I've done since I got the car (22 samples now) has shown....>> Sample sent off to Blackstone
On the catch can here.....
It holds about 7oz and the only time I get oil in it is during track use. The point of my CC was to keep the oil out of my charge pipes/IC. The oil that causes IVDs is not going that way on this car, it's going directly to the intake valves via a port in the block under the PCV...the low-throttle/idle vacuum port (which is a common misconception....that the oil going through the hose to the turbo inlet is where those come from...). Pushing hard, I've filled it in 20 min so figured I dumped ~1/2-3/4 a qt back in over the weekend. Silly to waste it. Overnight, I've seen water condense in it where you get a coffee colored liquid so I pitch that but during the day...I just chuck the oil back in. Many of the aftermarket PCV replacement "plates" utilize a sump drain back so on those, it's all going back which is of course...fine...
It holds about 7oz and the only time I get oil in it is during track use. The point of my CC was to keep the oil out of my charge pipes/IC. The oil that causes IVDs is not going that way on this car, it's going directly to the intake valves via a port in the block under the PCV...the low-throttle/idle vacuum port (which is a common misconception....that the oil going through the hose to the turbo inlet is where those come from...). Pushing hard, I've filled it in 20 min so figured I dumped ~1/2-3/4 a qt back in over the weekend. Silly to waste it. Overnight, I've seen water condense in it where you get a coffee colored liquid so I pitch that but during the day...I just chuck the oil back in. Many of the aftermarket PCV replacement "plates" utilize a sump drain back so on those, it's all going back which is of course...fine...
My catch can juice smells of gasoline, mushrooms, and partially burned underwear.
Patman
Staff member
Now I’m questioning exactly where you have placed that catch can
This where some folks get confused between the use of a catch can for racing purposes, and one to collect oily blowby moisture for your car. They seem to think its the same as whats collected from the intake manifold port side of the PCV at idle and low boost, whereas, what you collect is primarily the greater volume of oil, due to being on boost, that will cause the PCV to go into bypass. This added bypass oil will precipitate back out into the oil separator system when off boost under normal conditions. Or in a racing situation where the catch can collects the additional oil that overwhelms the traditional bypass type operation and cannot get precipitated back into the PCV system because the manifold vacuum side doesn't activate much, if at all, under WOT/boost conditions, ie; racing. Ergo, it's just plain ole crankcase oil.
2023 Toyota Corolla Cross hybrid
60 k on unit 10 k on oil
In/out Both Valvoline restore and protect 0w20 and an ep filter from carquest P85394
This is my fifth consecutive oil change with VRP all except the first change were 10k intervals. Nothing to report.
Average mileage this interval. 46.6 mpg.
More high speeds and max AC this interval. So using the battery reserves for personal comfort over max mileage..lol
60 k on unit 10 k on oil
In/out Both Valvoline restore and protect 0w20 and an ep filter from carquest P85394
This is my fifth consecutive oil change with VRP all except the first change were 10k intervals. Nothing to report.
Average mileage this interval. 46.6 mpg.
More high speeds and max AC this interval. So using the battery reserves for personal comfort over max mileage..lol
Delicious.
You are a gentleman and a scholar. Great description and spot-on.
And to add - on the MK7s, depending on the year, you can get billowing white smoke out of the exhaust under certain conditions from oil ingestion. Typically HARD braking followed by a right turn and as you bleed on throttle oil that has surged up the block into the PCV is released into the intake valve vacuum passage before the PCV can close that valve. The replacement PCV plates folks get that usually call them "catch cans" eliminate this issue by blocking the vacuum port to the intake valves in the block thus eliminating this issue...however...they then can cause issues b/c the crankcase will have some minor positive pressure at idle/low throttle conditions.
Nasty, and yes it's intake variety and yes moisture gets all up in there. It's NOT mostly oil. The good news, it's not very much volume.
- Joined
- Nov 23, 2025
- Messages
- 64
2018 Subaru Legacy 2.5
92,286 miles on vehicle
3,575 miles on oil
Out:
Mobil Full Synthetic High Mileage 0W-20
(Full quart Valvoline R&P 5W-30 and > half quart FVP Synthetic 5W-30 added)
STP S4615 Filter
In:
1 quart Valvoline R&P 5W-30
4.1 quarts Valvoline Hybrid 0W-20
Microguard Select 57055
Genuine Subaru PCV valve & hose
Weird mix, but I have a bunch of this stuff in my stash. It's smooth as silk though; the Subaru has never been quieter. I may clear out every Advance within a 100 mile radius just to get my hands on as much as I can.
Desperately need a fan in the garage though.