[VE] VZ and VE Alloytec PCV Problem/Fix

[greenacc]

OK, thanks for directing me here, immortality.

Although I pulled the motor apart to clean sludge, I never cleaned the PCV valve.

Mine is 235 000km, and still tight as. (I have to say, they are an awesome car. Last Holden I owned before this was an HZ wagon with 3 on the tree, ha ha, so this seems like the height of modernity. A four speed gearbox was my absolute dream as a young man. And I swear to god they are easier to pull apart and put back together than my fishing reel.)

But oil has been going up the air intake pipe like nobody's business, and there is a belch of smoke when I start it up.

I am going to pull it out now. This will be interesting.

Also, I see it is the same nice guys putting their heart into helping everyone out in every thread. Thanks a lot.

Which oil have you been using? I'm convinced the cheaper semi synthetic oils smoke more and block the PCV. Whereas good quality Full synthetic oil gives off virtually no smoke and won't block the PCV until about 300,000 ks.

 

[wannaeatyourbrains]

My PCV is clean as a whistle! Trying to upload a pic, but file size is too large. Absolutely clean as inside, holes not restricted at all.

But yes, I am using the cheapest semi-synthetic oil I can buy. 5w 30 Ford Motorcraft. $4 a litre.

Interestingly, oil problem has totally stopped since I changed the fuel return valve, and I no longer have vacuum in the tank. That was making it blow oil. I just totally cleaned the fuel system and put in new coils and injectors, too.

Air intake doesn't have a drop in it now. Maybe the smoke on starting is residue left over from the problem I had with the right bank not firing properly, broken camshaft position sensor wire. It would have filled the exhaust with oil for sure. Haven't really gone far or fast since then.

Theory about the cheap oil sounds totally sound, but. 'Synthetic blend', they say, ha ha.

 

[wannaeatyourbrains]

I got a new theory about the belch of smoke on a cold start sometimes.

The rings are feeling a bit tired because I thrash the **** out of it at every opportunity.

It feels so good.

 

[wannaeatyourbrains]

Actually, the smoke cleared up. Hard to say if it was anything to do with messing with the PCV valve or whether the air filter was just clogged from dust, cause I changed that at the same time.

Common problem here, a brand new one can become clogged after driving 10 minutes down the highway, there is so much dust in the air sometimes when the wind blows off the desert. Looks clean as, but completely stuffed with silica particles. (Interestingly, another common problem is complete loss of paint off the front end, and headlights that look like a piece of beach glass, after an hour driving because of sand scouring.)

What I wondered is, why is it that the smaller holes are different sizes in the first place? There is nothing inside the valve that I can see. Is there anything in there? It's a mysterious device.

Anyway I was dubious about just drilling them both out to the same size - as Lucretius put it, 'nothing from nothing ever came' - so I enlarged them proportionally.

Don't notice anything different about how the car goes. But that's not surprising, because it is made of lots of different cars. It's just to drive, ha ha. Refinements aren't my thing. I don't think it could go any better anyway, they are great cars.

There is sure as **** oil deposits in there again, but. Only 30 000 since I cleaned it, and they are back...

The catch cans came in the mail, so I might as well put them on. Got them now. Might save me some effort down the track.

Thanks all for your help. Much appreciated. Still charging.

 

[greenacc]

There's nothing inside the PCV on an Alloytec, it's just a hollow tube with holes in it. Problem was the original holes were too small to properly vent all the crankcase gases and smoke. So, drilling them larger increases the flow through the tube so allows the engine vacuum to extract all the smoke so it doesn't condense in the rocker cover filling it up with ****!
So Nothing is achieved without doing something there's no reason they should be different sizes, no doubt some engineering department couldn't make their minds up so went with one of each size. I think catch cans are a waste of time once you have drilled out the PCV.
The engine will happily burn all that hydrocarbon **** at the rate it's produced without blinking an eye. It's like putting tomato sauce on your sausage. Don't waste your time catching it and tipping it in the bin

 

[wannaeatyourbrains]

I love the analogy. But I laughed a lot. Never have I applied tomato sauce.

 

[Dayvo]

There's nothing inside the PCV on an Alloytec, it's just a hollow tube with holes in it. Problem was the original holes were too small to properly vent all the crankcase gases and smoke. So, drilling them larger increases the flow through the tube so allows the engine vacuum to extract all the smoke so it doesn't condense in the rocker cover filling it up with ****!
So Nothing is achieved without doing something there's no reason they should be different sizes, no doubt some engineering department couldn't make their minds up so went with one of each size. I think catch cans are a waste of time once you have drilled out the PCV.
The engine will happily burn all that hydrocarbon **** at the rate it's produced without blinking an eye. It's like putting tomato sauce on your sausage. Don't waste your time catching it and tipping it in the bin

I have had a catch can for a while but only recently drilled out the pcv valve. Will be interesting to see how much oil is in the cam at next oil change. And as for dipping my sausage in sauce , is that a euphemism ?

 

[greenacc]

LoL bwahaha, euphemism yes, for the oil smoke and blow by gases mixing with the fuel mist from the injectors, like a sausage with sauce on it. It's all just food for the internal combustion engine.
But if your mind is as dirty as your catch can you can believe otherwise if you like

 

[wannaeatyourbrains]

I will admit to not knowing the guy who invented it, or anything at all beyond the general principle of the thing. But I can't sleep at night now from not knowing. With full respect to other theories, and ketchup, I would like to have a stab at it myself.

If it is indeed a hollow chamber, and they have gone to the trouble of making the thing at all and not just directly venting the blow-by through a tube, the purpose of the different size holes might be to make a little vortex inside that chamber.

To my thinking, it could either be to ensure nothing solid makes it through that last trap. Or, more likely, given conventional valves, to regulate the flow. Increased vacuum would cause increased resistance, because the vortex would swirl faster, right? I mean, if it was sucking too hard, then **** would get sucked up there for sure.

Anyway, I have so fucked with it now with my drill, ha ha. Let's see how it likes that.

I am gonna put the catch cans on because I have bought them, and because they look like parts from the Death Star. Surely Darth Vader can make improvements.

It will allow me to satisfy my curiosity about whether much **** is coming through that valve, and whether the more expensive oils are that much worth it. Maybe too I have now caused more **** to be inhaled.

 

[Immortality]

I'd suggest differing hole sizes has to do with rate of change of flow and possibly pressure/vacuum differential to help drop oil mist out of suspension and allow it to return to the engine instead of going with the gasses back into the intake.

You have to remember that the PCV system is a metered air "leak" from in front of the TB via the crankcase going back into the intake manifold.

A catch can doesn't fix the PCV valve, rather it is there to stop said oil vapours from going back into the intake and covering everything in oil which is more critical on anything that is direct injection as the intake port/valves don't get washed down with fuel on every intake stroke. Been that I play with older cars/engines, cleaning out TB's etc from all the crap that has built up from the PCV system gets a bit boring when it could have been fixed from the factory which GM kinda finally did a year or 2 ago with the clean air separator they fitted on the later V6 engines.

And I love my sauce and will happily have sauce with my sauce...