Understanding the MK7 PCV function, retrofitting the MK8 PCV, and why catch cans are bullshit(IMO)

[Nineeightyone]

Bunch of relevant PCV related stuff in the last two trip reports:

https://www.datadrivenmqb.com/tripreports/fastivus2024

https://www.datadrivenmqb.com/tripreports/2024tsccax7

It's really looking like for the later cars, it's looking like the MK8 full retrofit should be a pretty good option for autocross, and probably fit the bill for tracks that aren't littered with multiple long sweeping RH turns over a relatively short lap.

I think 15-16 GTI in particular need to try either an AP or maybe BM valve and *maybe* with a BMS catch can, but if that's no good then straight to a PCV plate.

The Golf R stuff has been much more of a mixed bag.

One interesting thing about the 15-16 vs 17-18 CXCA/CXCB pistons was sort of found here... which definitely could explain why there are such stark differences on the early cars. I suspect it extends to the early CXBA and CXBB 1.8s as well. Basically everything with the 06H 198 151 F piston rings stock looks like it it has a low likelihood of success if asking it to do track or autocross.

https://www.golfmk7.com/forums/index.php?threads/piston-markings-decode.453080/

View attachment 311711

Dummy attempt at translation of this, but looking at the parts website, this seems to basically imply that later cars will have less issues related to rings?

 

[tigeo]

Can confirm. 16 1.8 AP so far so good, but haven't done track yet with it (& probably not anyone soon)

So I had smoking on my 18 1.8 with the AP which was the original. So funny this issue. BL sorted it and now same results with MK8 both in normal and full retrofits.

 

[MonkeyMD]

So I had smoking on my 18 1.8 with the AP which was the original. So funny this issue. BL sorted it and now same results with MK8 both in normal and full retrofits.

Yeah, i think the AP only works on 2015-2016

 

[perogi__peterson]

Awesome thread and amazing research by DerHase and others here. Does anyone know what is the best way to hook the mk8 venturi up to a Vortex XL, is it the 034 motorsports TMD? I don't have the XL yet, but going to put in the mk8 pcv (without venturi) when I replace my timing cover gaskets and will do the venturi when I upgrade the turbo later on.

 

[scrllock]

Awesome thread and amazing research by DerHase and others here. Does anyone know what is the best way to hook the mk8 venturi up to a Vortex XL, is it the 034 motorsports TMD? I don't have the XL yet, but going to put in the mk8 pcv (without venturi) when I replace my timing cover gaskets and will do the venturi when I upgrade the turbo later on.

Yes, the Vortex has an OEM inlet/outlet, so any bolt-on turbo muffler delete works.

 

[Jcris]

After reading through a lot of this thread and watching several YouTube videos I’m amazed at the depth of detail and knowledge you guys have. There’s no way I really understand some of this stuff but do appreciate the experience here. So , of course I have a question: I have a 2016 gti 2.0t with dsg. Just bought it couple months ago. It has a VWR catch can on it, a VWR turbo inlet and a Neuspeed TMD. This is a daily driver and will never be tracked. I want to replace the catch can with a stock pcv. Should I do the mk8 version or just use a stock pvc?

 

[MonkeyMD]

After reading through a lot of this thread and watching several YouTube videos I’m amazed at the depth of detail and knowledge you guys have. There’s no way I really understand some of this stuff but do appreciate the experience here. So , of course I have a question: I have a 2016 gti 2.0t with dsg. Just bought it couple months ago. It has a VWR catch can on it, a VWR turbo inlet and a Neuspeed TMD. This is a daily driver and will never be tracked. I want to replace the catch can with a stock pcv. Should I do the mk8 version or just use a stock pvc?

I would do the owm AP pcv

 

[tigeo]

After reading through a lot of this thread and watching several YouTube videos I’m amazed at the depth of detail and knowledge you guys have. There’s no way I really understand some of this stuff but do appreciate the experience here. So , of course I have a question: I have a 2016 gti 2.0t with dsg. Just bought it couple months ago. It has a VWR catch can on it, a VWR turbo inlet and a Neuspeed TMD. This is a daily driver and will never be tracked. I want to replace the catch can with a stock pcv. Should I do the mk8 version or just use a stock pvc?

Use what the current revision of the MK7 PCV is for your VIN, no need to change it here.

 

[DerHase]

After reading through a lot of this thread and watching several YouTube videos I’m amazed at the depth of detail and knowledge you guys have. There’s no way I really understand some of this stuff but do appreciate the experience here. So , of course I have a question: I have a 2016 gti 2.0t with dsg. Just bought it couple months ago. It has a VWR catch can on it, a VWR turbo inlet and a Neuspeed TMD. This is a daily driver and will never be tracked. I want to replace the catch can with a stock pcv. Should I do the mk8 version or just use a stock pvc?

OEM (AP most likely, but verify via VIN through a dealer) PCV + OEM turbo inlet.

 

[Jcris]

So,
Just the oem pcv wouldn’t be enough, the turbo inlet would also need to be replaced. I’m sure the previous owner put the inlet on to improve flow and to get more durable aluminum part. I might be wrong but wasn’t the stock inlet plastic?

 

[Nineeightyone]

So,
Just the oem pcv wouldn’t be enough, the turbo inlet would also need to be replaced. I’m sure the previous owner put the inlet on to improve flow and to get more durable aluminum part. I might be wrong but wasn’t the stock inlet plastic?

Stock part is plastic, but durability shouldn't really be a concern. Mine's changed out because it was a part of the whole kit I bought, honestly I wouldn't fret too much about the TIP itself unless you're having issues. Get back to the regular PCV, and if you don't have smoke on corners, enjoy the car as it is. Just my $0.02, I'm not smart though so see what others say/go with your gut.

 

[scrllock]

After reading through a lot of this thread and watching several YouTube videos I’m amazed at the depth of detail and knowledge you guys have. There’s no way I really understand some of this stuff but do appreciate the experience here. So , of course I have a question: I have a 2016 gti 2.0t with dsg. Just bought it couple months ago. It has a VWR catch can on it, a VWR turbo inlet and a Neuspeed TMD. This is a daily driver and will never be tracked. I want to replace the catch can with a stock pcv. Should I do the mk8 version or just use a stock pvc?

For street vehicles, I think the best option is the latest part number for your motor (06K-103-495-AP). The Mk8 full retrofit does a pretty good job at solving the track issues, but I don't think it's worth the money once you pay for the stupid line and 034 TMD.

 

[Ouzen]

Hey all, I've been diagnosing some oil seepage and real rough idling and remembered reading about the MK8 retrofit research that was being done. Finally delved through all of it, and it seems like the full retrofit would be the best fit for my needs, based on all the info I've watched/read. However I wanted to confirm and get some feedback before following through with the purchase and installation.
For context, I have a 2017 GTI Sport w/ fully built engine (engine has ported Golf R head, to complicate things), Vortex XL BB, MST TIP/intake, and Spulen CC/plate with ~58k mi. The car only sees the street these days as a daily, but still gets abused. The catch can and accompanying plate have been on since the engine was put in ~9k miles ago, so not sure if BM revision would be sufficient. It seems like the 2019+ cars are more suitable, which gives me pause.

My question would be; can I save some cost with the OEM (~$225) vs full retrofit (~$410)? Not sure how much longer I plan on keeping the GTI.

Much thanks for all the information and help.

 

[tigeo]

Hey all, I've been diagnosing some oil seepage and real rough idling and remembered reading about the MK8 retrofit research that was being done. Finally delved through all of it, and it seems like the full retrofit would be the best fit for my needs, based on all the info I've watched/read. However I wanted to confirm and get some feedback before following through with the purchase and installation.
For context, I have a 2017 GTI Sport w/ fully built engine (engine has ported Golf R head, to complicate things), Vortex XL BB, MST TIP/intake, and Spulen CC/plate with ~58k mi. The car only sees the street these days as a daily, but still gets abused. The catch can and accompanying plate have been on since the engine was put in ~9k miles ago, so not sure if BM revision would be sufficient. It seems like the 2019+ cars are more suitable, which gives me pause.

My question would be; can I save some cost with the OEM (~$225) vs full retrofit (~$410)? Not sure how much longer I plan on keeping the GTI.

Much thanks for all the information and help.

Full retro including the 034 TMD should be about $325. I'd just use whatever MK7 OEM part for your VIN and start there.

 

[Jcase2210]

For street vehicles, I think the best option is the latest part number for your motor (06K-103-495-AP). The Mk8 full retrofit does a pretty good job at solving the track issues, but I don't think it's worth the money once you pay for the stupid line and 034 TMD.

I got my dealer to pay for the full retrofit kit cause i complained about the burning oil a month after I bought my 17 wagon. Simply asked if they’d cover it and said it would make me drop it