That makes sense. Is more or less vacuum better? Dude goes so in depth it's difficult for me to follow. Is it too much vacuum that kills the stock pcv?
7
Understanding the MK7 PCV function, retrofitting the MK8 PCV, and why catch cans are bullshit(IMO)
- Thread starter DerHase
- Start date
DerHase
Autocross Champion
- Location
- Hampton Roads, VA
- Car(s)
- 2019 GTI Rabbit
Too little vacuum hurts OEM style PCVs ability to separate oil so it gets sucked up. Keep the stock TIP if you have a MK7 valve or MK8 basic retrofit and plan on auto-xing or tracking the car. On the street will likely have little to no noticeable bad issues though.
Too much vacuum when used in conjunction with the full retrofit Venturi doesn't have any noticeable side effects, but erring towards less vacuum from the TIP (BMS TIP instead of stock, for instance) SEEMS to allow the diaphragm to remain more stable. Either one will function better than an OEM PCV, though long term effects are less known.
If you have a PCV plate - Looking into this currently but I'd err towards something that has less vacuum since there is no regulator to dial it down to reasonable levels (risk of sucking oil out of the cyl head and filling the can faster).
Got the full retrofit installed on my 2015 A3. One tip is that for the PCV, make sure you have a thin enough T30 socket to get to the PCV bolt next to the HPFP, my 3/8 drive one was too wide and I had to go out in the middle of the job to get something thinner.
Also, it seems like most people are using the left side of the 034 TMD, I used the right. I don't know if 034 made a design change or if the A3 is slightly different, but I had to use the right side to get the proper fit. Check fitment before installing your fittings. I also used both fittings to have more clearance to tighten down the hose clamp.
The last tip is for the hose to easily connect to the PCV, you need to come at it, as straight and flat as possible, otherwise it won't click in.
Only "bad" part is I never took it to the track with the stock PCV, so I can't say if this helped or not. Hopefully getting it to NJMP Lightning this week.
Also, it seems like most people are using the left side of the 034 TMD, I used the right. I don't know if 034 made a design change or if the A3 is slightly different, but I had to use the right side to get the proper fit. Check fitment before installing your fittings. I also used both fittings to have more clearance to tighten down the hose clamp.
The last tip is for the hose to easily connect to the PCV, you need to come at it, as straight and flat as possible, otherwise it won't click in.
Only "bad" part is I never took it to the track with the stock PCV, so I can't say if this helped or not. Hopefully getting it to NJMP Lightning this week.
Klrider44
Go Kart Champion
- Location
- Bucks county PA
Do you use any type of thread sealant on the tapping piece? was thinking about throwing some blue thread locker on there.
PerceivedShift
Autocross Champion
- Location
- Virginia
Yea, I used some blue thread locker.
DerHase
Autocross Champion
- Location
- Hampton Roads, VA
- Car(s)
- 2019 GTI Rabbit
From what I can tell that's an oil pressure sensor/performance related code. (Not PCV related).
What oil weight?
That's what I came up with but I'm stopping at the dealer on the way home to see if I can get a more definitive diagnosis. Likely just a sensor.
5w-40
Little update. Unable to get the code read today, but it goes away on its own with an engine restart. I still need to find out the cause so it doesn't keep cutting my track sessions short. Also, my oil cap is leaking (easy enough to replace), possibly the upper timing cover even though it was just replaced (hopefully just a drip from the oil cap), and the pipe that attaches to the passenger side of the intercooler was full of oil (a lot more than normal).
Klrider44
Go Kart Champion
- Location
- Bucks county PA
I could be wrong here, but it seems like the majority of these cars “sweat” a bit of oil from the upper timing cover.
DerHase
Autocross Champion
- Location
- Hampton Roads, VA
- Car(s)
- 2019 GTI Rabbit
What's the turbo/TIP/tune combo(max psi?) out of curiosity?
When you remove the oil cap do you sit it upside down? If so that's part of the problem. Oil runs "up" beyond the square cut seal o ring and when reinstalled will wick out with heat.
IS20/stock TIP/ EQT stage 1 93 octane (not sure max PSI).
Oil cap never had a leak prior to taking it to the track. It's likely the original 10 year old one on there so it wouldn't surprise me if the seal was bad.
DerHase
Autocross Champion
- Location
- Hampton Roads, VA
- Car(s)
- 2019 GTI Rabbit
Got it. The real question is how much oil are you burning between sessions/over the day?
I did experience some oil burning with full retrofit + OEM TIP, but only on my high boost map (which is still weaker than an EQT OTS map). But it was also with my ventilated valve. IIRC I went through a little under a quart over the full day, with also renting my car out Saturday (so it saw double the normal track time). But no KR that could be correlated to oil burning.
https://www.datadrivenmqb.com/tripreports/vir-with-tscc-december-2023
I ran an unmodified valve in full retrofit form back in October... But it was a busy weekend focused on getting my instructor license and taking care of my student. My pace was a bit slower that weekend, and I don't think I ran my high boost tune the full weekend also?
https://www.datadrivenmqb.com/tripreports/oktoberfast23
Not sure if you saw but it appears that higher flowing aftermarket TIPs pair better with the Venturi since they don't pull such a ridiculous amount of vacuum.
I'm about to start experimenting with 3/16in fittings + hose to the Venturi in an attempt to dial it down some so it could work better with stuff like OEM TIPs and probably higher boost setups as well.
Realistically I think we need about -2.5 to -3.5psi at most to ideally keep the diaphragm from bouncing around.
https://www.datadrivenmqb.com/drivetrain/just-the-tip-testing
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