Vacuum pump and PVC questions.

[jaed_43725]

I heard that I need to have the PCV hooked up to the intake on my IDI otherwise it causes problems with the piston rings. Is this true in any manner? I am running RDT because I really hate that crap going into my intake and turbo. Do I need to use the PCV for any reason? At the same time I was told that these engines need to have it hooked up to create vacuum in the crankcase in order for the brakes and such to work properly. Now from my understanding diesels are a 0 vacuum engine, and all vacuum is made by the vacuum pump. So if I am having some sort of vacuum issue and my lines are good, shouldn't I just replace or rebuild the pump? On top of that, is there a higher performance vacuum pump available, or a way to mod the current one to make it better? Any information about this would really help. Thank you.

[CRSMP5]

who ever is learning you needs hit in head with lead slug powered by gunpower... all nonsence/bs...

unlearn that info.. and enjoy a forum of good info..

[jaed_43725]

I didn't take the advice to strongly as they are a VW gas person. And diesels are a whole different ball game.

But still need some info on what I asked about the vacuum pump.

[745 turbogreasel]

You need the CDR valve to regulate flow, and the vac pump to scavenge the case.
Where it vents doesn't matter much to the engine, but separators are easy to build, or cheap to buy, I don't see why you'd chose to spew the stuff across the belly of your car.
What is wrong with the oil fumes entering the intake? You have a $1000 pump designed to spew oil into the engine. My turbo has 270,000 miles in PCV vapors, and seems to be doing fine.

The stock Vw pump is good enough to run brake booster and vents control, how much more performance do you need?
pull the big hose off it with the engine running, put your hand over the nipple...if you don't feel vacum, it's broken.

[ORCoaster]

Let's do this one at a time shall we?

Now from my understanding diesels are a 0 vacuum engine, and all vacuum is made by the vacuum pump.
Bingo!  Unless you want to count the fact that as the piston draws down on one stroke it is pulling a vacuum then.  But as for a vacuum in the intake manifold it is near zero.

Next:
So if I am having some sort of vacuum issue and my lines are good, shouldn't I just replace or rebuild the pump?
Maybe Bingo.  If you ruled out the lines by putting your finger over one end and sucking on the other that might be OK but what about the seal where it goes into the brake booster or the booster itself.  Did you check the funny little plug thingy for a crack?  How about the check valve in the line to the booster.  Did you draw a vacuum on it and did it hold?  Gauge in line to determine leakage over time?  

Next:
On top of that, is there a higher performance vacuum pump available, or a way to mod the current one to make it better?
Well what kinda pump you got?  The first go around for this little devils was a diaphragm style that has issues with the rubber parts, the seals and the O ring going bad.  About a 10 dollar fix for a rebuild kit.  Later in life these were magically transformed by the diesel tooth fairy into a vane style pump.  It spins a gear like mechanism and develops a vacuum through mass flow of glitter and voodoo.  Really nice to have one of them on.  So yeah, it could be considered a performance pump compared to the suck and barf style but there isn't a good way to modify either to make them better than they are.  

Any information about this would really help. Thank you. You are welcome, please pay the cashier at the front of the store and please come back soon.  DAS

[bajacalal]

I didn't take the advice to strongly as they are a VW gas person. And diesels are a whole different ball game.

But still need some info on what I asked about the vacuum pump.

Some of that stuff isn't even correct for a gas engine.

But in any case, I wouldn't mess with the factory crankcase ventilation system, other than installing the upgraded "hockey puck" oil strainer and plate if you have the older non-turbo engine which didn't come with these... It doesn't do anything, from a performance standpoint, to vent the crankcase to atmosphere. Your diesel engine does not care about a little bit of oil getting sucked in the intake. And, you will probably smell the odor of burnt oil inside the car if you do.

[wolf_walker]

I never understood why people vented to atmosphere, pulling the vapors back into the intake is a good plan unless there are a TON of them, in which case something is worn out.
It looks a bit icky to have oil all in there but it isn't hurting anything.
The later "hockey puck" is basically an oil separator, designed to let vapor pass but give the solid oil a chance to drip back into the intake, it's a better setup and VW used it for a long time.
Nothing wrong with a regular catch-can either, it's the same vein as the factory oil separator. 
Try and use oil rated hose for that stuff, which isn easier said than done.  Heater hose isn't, and all fuel line isn't. 

And the later small rotary vane style vacuum pump is a nice upgrade if you can find one, I don't know that it pulls any more
vacuum but it's less in the way and seems to last longer.  It's nice one can rebuild the early style, but the later one's never seem to need it.

The early style has a hose going to a plate with a nipple on the block, I think it's where the mechanical fuel pump used to mount on
the old carb'd gas motors, it pulls exhausts into the block there.  The later style just had a flat blockoff plate.  I assume the later one
exhausts into the block internally but I can't remember for sure.

[745 turbogreasel]

The hockey puck isn't much of a separator, It's main purposes in life are to regulate the swept volume and case pressure so that you don't blow seals out form too much pressure, or blow all your oil through the bent system from too much volume.  The second major function is to slam shut in the event of too much venting volume, to prevent a blowby fueled runaway when you've holed a piston or something.  It works too, I had one hold enough crankcase pressure that  it launched the oil cap so far I could not find it afterward. Real  oil vapor separation  requires a bit more volume than the hockey puck.

[wolf_walker]

That's interesting, makes sense though.

Volvo manages oil separation with a container that size on the old redblocks, I assumed from that it was similar.
They seemed to be trying to keep actual oil away from the vent area with that plate on top of the cam they added
along the way somewhere.  I never could find a good technical description of it, thanks.

[jaed_43725]

My brakes work fine. This was more a question of do I actually have to run the PCV into the intake. I can see the answer is no. I am going to keep RDT because I don't like crap going into my turbo and intake. I will be changing the vacuum pump however to the newer style maybe. Perhaps the heat will work better and the brakes my improve some as well. I have a bad vacuum pump on my truck and it stops like crap and the heat quit working because of that. And I don't feel like messing with it much later.

I am going to do some research on electric vacuum pumps like the one on a 03' 7.3 PowerStroke. That might be a better solution.

[wolf_walker]

Electric pump's been used on a lot of diesels, and no few gassers, but they are a solution looking for a problem on a VW-D.
The late style pump works for decades and handles the brakes and HVAC easily.  Plus you'd have to plug the hole.

[R.O.R-2.0]

Electric pump's been used on a lot of diesels, and no few gassers, but they are a solution looking for a problem on a VW-D.
The late style pump works for decades and handles the brakes and HVAC easily.  Plus you'd have to plug the hole.

yea the stock vac pumps work way good enough already.

an electric pump would likely put more load on the engine than a mechanical pump..

[jaed_43725]

 Thanks for the info.  I will be putting on one of the better ones soon then.

[wolf_walker]

Nothing more than an interesting tidbit... 

http://www.mikegabriel.net/vw/dieseltraining/diesel_training-126.html