Question:
'There is oil all over the back of my car, how can I stop
that?'
or
'I have a breather kit, where do the hoses go?'
Type I ACVW engines were built without a seal on the rear
(FIF, Pulley end) of the crank shaft.
Trust me when I say that VW's did not leak or drip oil
when they were brand new. Hard to believe, I know, but true.
So what has happened to the engine to make them mark their spot now?
Well, years of back yard mechanics and people who's motto was 'You can't kill a VW' have taken their toll. Maybe you can't kill them, but they can sure suffer for a long time.
All internal combustion engines have what is referred to as 'crank case pressure'. One of the first anti pollution devices installed on American cars was the PCV valve, or Positive Crankcase Ventilation valve. Basically it was a little ball held in place over an orifice connected to a hose that went to the oil pan, or crank case. The other end went to the air cleaner. When pressure built up inside the crank case due to ring blowby, the pressure would force the ball up and the gases inside the crank case would be sucked into the air cleaner. All the bad gasses would then be burnt off thereby creating a wonderful atmosphere and clean air for all the children and small animals to breathe.
On early ACVW's, the vent was simply routed under the car and the gases were vented into the atmosphere. Later models had a hose going to the air cleaner which did what is described above. To my knowledge, no valve was employed, at least not on 68 thru 72 models.
OK, so the engineers designed the size of the tube and the hose going to the air cleaner to handle the amount of blow by and pressure created in the case in a stock engine.
But now us folks come along and decide we don't like the stock oil bath air cleaner and replace it with one of those really spiffy chrome jobs from Taiwan. But you may notice one thing, the spiffy chrome job either has no fitting for a hose going to the oil filler or the diameter of the hole in the fitting is smaller than the one on the stock fitting.
So what happens? Pressure builds up inside the case, (normal) but now it can't get out of the hose. It has to go somewhere, guess where? Remember that pulley mounted on the crank that has no seal? You guessed it, the pressure comes out there and since it is closer to the oil level, some oil sprays out with it.
One fix for this is to add ventilation to the case. There are many ways to do this, one of which is to purchase a breather kit which normally includes a breather box and fittings and hoses to connect to the engine. Typically, holes are drilled in the valve covers and fittings installed there for hoses to run back to the breather box. There are some other difficulties to overcome in a stock bodied car like getting the hoses from the valve covers, outside the engine compartment, to the breather box, which is normally mounted inside the engine compartment.
The breather box should be mounted above the engine crank case, so that any oil that is blown up into the hoses will drain down back into the engine.