IDI high RPM run away. From crank case vent. 1984 Jetta TD

[DRP67207]

Thanks for the reply ORCoaster, sounds like I'll tee into both and should be good.

A few more questions out of curiosity however.  In this picture here, is there another hose coming out the back of the hockey puck and going to the EGR system or something?

Also, how exactly does tying into the vacuum pump line prevent oil vapors from getting into the intake? Still figuring out these diesels and trying to learn as much as i can about 'em.  Thanks.

[ORCoaster]

I am not familiar with this style of vent so someone else take it from here.  Is it that little bit of a nipple looking thing left of the hose clamp? 

As for our 1.6's near as I can tell, and by the way I have that similar problem.  Air cleaners all oiled up but not quite to running away yet.  The piston goes up and down and most of the air coming in goes out the exhaust.  Until the engine gets tired and worn out, or in my case breaks a ring on a piston.  Then some of that air goes past the piston as compression builds and possibly as it pops off at the ignition point.  Now we end up with a crank case that is slowly pressurized. 

Oil drain holes in the head double as air vent holes but with a lot of air coming up the oil tends to spray around under the cover and where does it go as well?  Out the hose and into the intake.  I think that is because the oil holes are in the corner of the head and close to that spot in the valve cover.  That is normally not a problem with a diesel as to the cylinder it is just more fuel.  More RPM more fuel, More RPM more fuel and soon you are no longer able to control the speed as it suddenly becomes possessed and gets a life of its own.  Run away. 

So what does adding a hose do?  I say it splits the amount of air going up the oil vent holes by a bunch.  Out the big vent hole in the front of the engine and without taking oil with it.  Oil can now drain into the engine as it should and not spray under the valve cover.  No more added fuel, so more RPM no longer equals more fuel and hence you control the speed and no more run away. 

At least that is my story and I will only change it if provided enough beer and beer logic to change it.

This is my understanding of the problem and the extra hose solution.  You can agree or not.  Just don't tell me. 

[8v-of-fury]

I am not familiar with this style of vent so someone else take it from here.  Is it that little bit of a nipple looking thing left of the hose clamp?   

AAZ/TDI style. It looks like a nipple but it is just a blank casting mark, which serves no purpose. They are a bolt on affair to the 1.6's as you can see.

[theman53]

that is my old 1.6 engine with the setup from the AAZ engine. I don't know if it was the breakin procedure or the hose to the block or both, but I didn't lose a quart of oil in 40,000 miles. I had some in the intake but it was not bad. My thinking was that it would help equalize the pressure all the way around. I just added it as it was a little cleaner than my other idea I made with a hose barb and a pipe tap.

[fatmobile]

Yeah, they used a fat hose on the AAZ engine, probably 3/4".
 Compared to the 5/8" MK1 hose.
 I've been drilling out the blockoff plates and tapping to fit 3/4" NPT and hose on my 1.6 TDs.
The gasser PCV puck will fit on top of the valve cover too, might be the same thing as the AAZ puck.