Advice on PCV setup

[Tzaks]

Updating this thread with my experiences and resolve, maybe someone will find it useful.

I used an10 hose between the Crankcase and catch can (low side) because I wouldn't be able to fit any PCV valve inside the hose. Even so, I had to use a dremel and grind a chinese PCV valve I got from aliexpress in order to make it fit.

This went inside the hose as previously mentioned and used a clamp on the outside so it doesn't have any chance of moving. I will create a mounting bracket soon for the catch cans.

For the vacuum opening I used the VTT vacuum relief valve which I honestly don't understand why it's being advertised for 10-12-14 inHG. That's a lot of vacuum and would cause a squealing noise because the engine is sucking air through the VC gasket. Below you can find vacuum values for crankcase for various BMW engines:.

17mbar = 0.5 inHG

Installed a filter on the vacuum relief valve so I don't pull dust and dirt inside.


I do get occasional puffs of smoke when coming to a stop. I believe that's because there's not enough vacuum in the crankcase. I did purchase a digital manometer which should arrive tomorrow and I hope that will help me dial in the crankcase vacuum accurately and solve my occasional puff of smoke. I have to mention that the downpipes were off about 6-800 miles ago and there was no oil inside which is why I don't think it's the actual turbos.

FYI:
The highside AC fabrication fitting is not sealing properly and leaks which is why I used a silicone hose instead.

 

[martymil]

I dial in about 2 inhg by taking all the shims out and trimming the coil about 1/4 turn at a time, if you trim to much
you can use the shims to bring it back up.

 

[Tzaks]

I ended up using a digital manometer since that was the only device I could find that would measure vacuum accurately in mBar. Dialled in the crankcase at 22 mBar since these turbos are bigger (19T) and would possibly benefit from extra flow. OEM is 17 mBar and BMW advises + - 10% is within parameters.

I T-ed in the crankcase an8 connection with an an8 1/8 npt. Installed a quick release pneumatic fitting, used a nylon tube and attached it to a vacuum line that was connected to the manometer. Pictures below of the fittings that I used.

Also, a weird phenomena was happening. When I had the PCV valve mounted in line on the low side and the one way check valve mounted right at the beginning of the hose that's coming out of the intake manifold, I believe the pressure inside the hose and catch can would cause both valves to shut off. Because of this, my crankcase would see positive pressure constantly and smoke. The manifold wouldn't be able to apply vacuum to the engine. Fixed this by removing the inline PCV valve, leaving the one way check valve next to the intake manifold and installing a brake bleeding nipple as a restriction on the hose. Works great.

I wrote here as much information as possible from my experiences, hopefully this will help someone someday. The PCV system is a very intricate and delicate system which needs to be setup properly. Failing to do so will blow your turbos or the whole engine.

Thank you for all the help from everyone that chimed into this thread. Special thanks to @martymil for his outstanding advice.

 

[TMX]

@Tzaks
So what is your final setup? I'm having smoking out of tail pipe issues, and have a feeling it is PCV system related. I have BMS high side OCC with OEM flapper. For the low side, I had RB PCV valve, then decided to upgrade to low side OCC. Setup and plumbing I had build was similar to BMS or RB. I used VTT PCV delete fitting on OEM manifold, 3/8" fuel line to OCC, 3/8" line to throttle body vacuum line connection T-ed in before little check-valve. The issues I saw with this setup - it was drawing way too much vacuum under intake manifold. I had to pull hard on oil fill cap to get it open while at idle.
I have ordered 2JZ PCV valve and plan on adding it inline past the OCC. Question is, do I still need to add vacuum relief valve to my valve cover?
Also, what is the benefit of running VTT fill cap with crankcase breather?

 

[ShocknAwe]

Getting ready to revise my low side, have AN8 vtt delete fitting to barbed 45deg adapter and 1/2" vibrant heater hose, then thinking 2jz valve to OCC to more 1/2" hose and check valve before TB.

 

[Tzaks]

@Tzaks
So what is your final setup? I'm having smoking out of tail pipe issues, and have a feeling it is PCV system related. I have BMS high side OCC with OEM flapper. For the low side, I had RB PCV valve, then decided to upgrade to low side OCC. Setup and plumbing I had build was similar to BMS or RB. I used VTT PCV delete fitting on OEM manifold, 3/8" fuel line to OCC, 3/8" line to throttle body vacuum line connection T-ed in before little check-valve. The issues I saw with this setup - it was drawing way too much vacuum under intake manifold. I had to pull hard on oil fill cap to get it open while at idle.
I have ordered 2JZ PCV valve and plan on adding it inline past the OCC. Question is, do I still need to add vacuum relief valve to my valve cover?
Also, what is the benefit of running VTT fill cap with crankcase breather?

Low:
AC fab An8 fitting connected to AN hose with a brake bleeding nipple on the hose to restrict flow > Catch Can (baffled with stainless steel scrubbers and 50 micron filter) > AN8 to intake manifold with 1 way valve as close to the manifold as possible.

High:
AN10 hose with 1 way check valve > Catch Can > Rear inlet.

Whatever you do my advice is to get a manometer to make sure your VC is under correct vacuum. It's around £40-50 on amazon.

In my case, I haven't used the 2JZ PCV valve anymore and used the brake bleeding nipple instead. A one way check valve next to the intake manifold is enough if the vacuum is dialled in properly. The PCV valve, from my understanding, is mainly used for restricting flow.

 

[TMX]

Low:
AC fab An8 fitting connected to AN hose with a brake bleeding nipple on the hose to restrict flow > Catch Can (baffled with stainless steel scrubbers and 50 micron filter) > AN8 to intake manifold with 1 way valve as close to the manifold as possible.

High:
AN10 hose with 1 way check valve > Catch Can > Rear inlet.

Whatever you do my advice is to get a manometer to make sure your VC is under correct vacuum. It's around £40-50 on amazon.

In my case, I haven't used the 2JZ PCV valve anymore and used the brake bleeding nipple instead. A one way check valve next to the intake manifold is enough if the vacuum is dialled in properly. The PCV valve, from my understanding, is mainly used for restricting flow.

You were checking your VC pressure while warmed up at idle correct?

 

[AWCR1MC]

The one thing I can never figure out is PCV setups….

I’m running the VTT dual can setup as picture, but without the oil cap breather. Ever since I switch to this I keep throwing the (2D2E Angle of throttle valve - intake pipe underpressure, correlation) code. I removed the check valve along with the throttle body PCV adapter and VTA to see if this would change things. It did, but now I have smoke coming out of the filters on idle. Is my only option to go back to running the PCV adapter connected to the throttle body for vacuum or is there an alternative route that would work better?

 

[ShocknAwe]

My suspicion is that every car is in varying degrees of accessory hard vac line failure and they all need to be replaced if literally anything is changed from stock on the PCV setup. Going through them 1 by one on my 1er and every part replaced improves the throttle bog I have. What a mess.

Then some aftermarket setups creates a too much vac problem as opposed to vac leak problem, which then necessitates these partial vta/relief parts. There doesn't seem to be a one size fits all product and only vac measurement and heavy maintenance scrutiny truly fixes things. Dunno.

 

[Tzaks]

@TMX - Yes, warmed up but also throughout as it was warming up. Give it some revs, see how fast the vacuum settles...

@AWCR1MC - Check for leaks, I believe you have a big vacuum leak which is causing the angle error code. This chap does a very good job at explaining how the whole system works.

I am pretty sure I saw on the n54 FB group some people that were showing the VTT throttle body adapter leaking.

Any aftermarket PCV solution should be tested IMO. Valve cover vacuum should be measured at idle through a modified oil cap or a T into the low side or high side.

 

[TMX]

Alright.. So messing more with PCV and trying to dial it in.. I put upgraded RB pcv valve back in stock location while was waiting for my 2jz pcv valve to come in. And after driving for few days, smoking stopped.. I received my 2jz pcv valve and installed low side OCC back in with 2jz valve past OCC before tapped nipple on manifold. connected manometer and monitored while at idle warming up. Vacuum settled down around 7.5 - 9 mmHg (10-12mBar). Car idled and ran good when took for test drive. No smoking. This morning started the car, and smoke started coming out again from both tail pipes... From looking at previously posted spec sheet by @Tzaks, it should be 17mBar. How can I increase vacuum and hopefully get rid of this annoying smoking issue?

 

[Tzaks]

Alright.. So messing more with PCV and trying to dial it in.. I put upgraded RB pcv valve back in stock location while was waiting for my 2jz pcv valve to come in. And after driving for few days, smoking stopped.. I received my 2jz pcv valve and installed low side OCC back in with 2jz valve past OCC before tapped nipple on manifold. connected manometer and monitored while at idle warming up. Vacuum settled down around 7.5 - 9 mmHg (10-12mBar). Car idled and ran good when took for test drive. No smoking. This morning started the car, and smoke started coming out again from both tail pipes... From looking at previously posted spec sheet by @Tzaks, it should be 17mBar. How can I increase vacuum and hopefully get rid of this annoying smoking issue?

Install a restriction between intake manifold and crankcase. Depends on how soft the tube is you could squeeze it while it's running and see if the vacuum is changing, it should.

 

[TMX]

Install a restriction between intake manifold and crankcase. Depends on how soft the tube is you could squeeze it while it's running and see if the vacuum is changing, it should.

Thanks man, that will be this evenings experiment. I think I have some brake bleeder valves laying around too. On your setup you jut put one inside the hose?

 

[Tzaks]

Thanks man, that will be this evenings experiment. I think I have some brake bleeder valves laying around too. On your setup you jut put one inside the hose?

No worries man, yeah I used a brake bleeding nipple from an old calliper but dialled it with the VTT vacuum relief valve at the front of the engine. This:

I didn't even use the 2jz valve anymore. Only used the brake bleeding nipple and used a one way check valve as close to the intake manifold as I could.

The adjustment came from that VTT vacuum relief valve.

 

[TMX]

No worries man, yeah I used a brake bleeding nipple from an old calliper but dialled it with the VTT vacuum relief valve at the front of the engine. This:
View attachment 56260

I didn't even use the 2jz valve anymore. Only used the brake bleeding nipple and used a one way check valve as close to the intake manifold as I could.

The adjustment came from that VTT vacuum relief valve.

So question on this. VTT valve is to relief too much vacuum in crankcase correct? I need to increase vacuum in mine, so I don't think it will work in my situation. Will try squeezing hoses while engine is operating and see how if vacuum changes.

 

[fmorelli]

So question on this. VTT valve is to relief too much vacuum in crankcase correct? I need to increase vacuum in mine, so I don't think it will work in my situation. Will try squeezing hoses while engine is operating and see how if vacuum changes.

Why are you lacking vacuum?

 

[Torgus]

Why are you lacking vacuum?

I always thought he sucked too.

J/K

 

[TMX]

Polished cams / overlap lol I'm at 11-12 mBar when should be at 17mBar. Think that's why vacuum is on lower end. So thats why I'm messing with the PCV setup and trying to dial it in and stop smoking out of tailpipe.

 

[doublespaces]

By now, someone could sell a biography about their PCV journey.

 

[fmorelli]

By now, someone could sell a biography about their PCV journey.

More like a short stories book.