[Engine] Having a Ponder ref Air Intake

[steve johnson]

Im not sure if this has been brought up before anywhere in the forums..but I cant find anything..or Ive overlooked the thread,
Ive been wondering about the Rocker cover venting back into the air intake system...to me it seems quite strange..but Im a novice with these engines so really have no idea why it should do so...when Ive been working on my engine..1.9 dw8 wjz..Ive noticed oil in the venting pipe...this is then being sucked into the air intake manifold then burned in the cylinders...this cant be good I would have thought..I would like clean air burned not contaminated air with oil deposits ( please remember that I know nothing about the workings of diesels)...would it be possible to vent the rocker cover pipe into a catch pot as was done on the old petrol engines in the 60`s and 70`s...then blank off the opening to the air intake...this is just something that Im thinking about but dont know if it would be ok to do this for some reason....your thoughts would be most welcome..I have attatched some pict for visual reference...    
   
    ...could anyone tell me what these 2 holes are for...they are drilled into the plastic intake at the front of the van before the air filter..they really suck in the air...
Hope Im clear enough on what Im thinking
Regards,
Steve...

[geoff]

The reason for the engine venting into the air intake system is for emission control reasons and has been going on for a number of decades now .....

I however ( amongst others ) have taken a step back in time and vented to atmosphere with a catch pot so you won't be on your own here.
I have to tell you take you run the risk of the planet huggers baying for blood and wanting to remove the contents of your scrotum for such a dastardly deed ...

The two holes, I've not noticed those before and if on my vehicle I'd tape them over. Apart from a noise potential I doubt they would affect anything.

[steve johnson]

The reason for the engine venting into the air intake system is for emission control reasons and has been going on for a number of decades now .....

I however ( amongst others ) have taken a step back in time and vented to atmosphere with a catch pot so you won't be on your own here.
I have to tell you take you run the risk of the planet huggers baying for blood and wanting to remove the contents of your scrotum for such a dastardly deed ...

The two holes, I've not noticed those before and if on my vehicle I'd tape them over. Apart from a noise potential I doubt they would affect anything.

Thanks Geoff..I think I shall go down the same route....after all if a catch pot is good enough for a classic Jag (pipe stuck in a jeys fluid can) its good enough for me...as for the two holes I shall put some tape over them..and if all goes well I shall pop 2 rivets in later...no I dea why they are there at all...strange...but then this little van throws strange things all the time... ...
Steve...

[Solent]

Re the little holes, on some engines the air intake is very low down to pull in cool air, should you be wading through water however, the holes will prevent water being sucked up into the engine so best to leave them clear. The idea is to starve the engine of air as there isnt enough vacuum to lift the water if that makes sense.

Obviously if the car is wading in very deep water nothing will save it, as my XZ found out in 2000, it was found quite a long way downstream of the ford I was trying to drive through.

[Jed Clampit]

Hi Steve i have blocked the hole on the air filter intake and vented the rocker into a catch tank then to air i also put some stainless steel scourers in the catch tank to catch tank any oil mist to stop the oil mist going to air just make sure you clean and check every now and then  and give it a clean it's not part of an MOT. 

[steve johnson]

Hi Steve i have blocked the hole on the air filter intake and vented the rocker into a catch tank then to air i also put some stainless steel scourers in the catch tank to catch tank any oil mist to stop the oil mist going to air just make sure you clean and check every now and then  and give it a clean it's not part of an MOT. 

Thanks Jed..that was the kind of Idea I had in mind...was thinking of sponge in the tank..but the scourers sound a lot better to me...so that little job is on the list now...will be interesting to see what I can come up with for this...
Steve

[Col]

You might find the engine weeps a little oil aferwards as the PCV system puts a vey slight vacuum into the crankcase which help draw the oil back into the engine in places where it could leak such as oil seals or rocker gaskets. Personally I would leave it as there are very few downsides with it in place, and the oil will stay cleaner for longer too.

[steve johnson]

You might find the engine weeps a little oil aferwards as the PCV system puts a vey slight vacuum into the crankcase which help draw the oil back into the engine in places where it could leak such as oil seals or rocker gaskets. Personally I would leave it as there are very few downsides with it in place, and the oil will stay cleaner for longer too.

Cheers Col...I see what your saying...what Im trying to do is stop/cut down on any oil going into the inlet manifold and reduce the smoke issue that I have untill I take off the head and do the valve stem oil seals...better still stop the initial smoke on start up without major surgery...so...If I put an "oil trap" of some description between the rocker and the air inlet that would at least reduce the oil if I had some kind of filtering in there... I know it may sound a bit whacky...keeps my mind active though ..ha ha
regards,
Steve..

[Col]

You might find the engine weeps a little oil aferwards as the PCV system puts a vey slight vacuum into the crankcase which help draw the oil back into the engine in places where it could leak such as oil seals or rocker gaskets. Personally I would leave it as there are very few downsides with it in place, and the oil will stay cleaner for longer too.

Cheers Col...I see what your saying...what Im trying to do is stop/cut down on any oil going into the inlet manifold and reduce the smoke issue that I have untill I take off the head and do the valve stem oil seals...better still stop the initial smoke on start up without major surgery...so...If I put an "oil trap" of some description between the rocker and the air inlet that would at least reduce the oil if I had some kind of filtering in there... I know it may sound a bit whacky...keeps my mind active though ..ha ha
regards,
Steve..

To be honest Steve, I don't think you will make any difference to the smoke, unless the engine is breathing really heavily, in which case the engine is knackered.
If the smoke doesn't have a blue tinge to it, then it's not burning oil.

BTW- I build engines frequently as part of my job, especially diesels. I picked up one yesterday that will be first job in the new year.

[steve johnson]

You might find the engine weeps a little oil aferwards as the PCV system puts a vey slight vacuum into the crankcase which help draw the oil back into the engine in places where it could leak such as oil seals or rocker gaskets. Personally I would leave it as there are very few downsides with it in place, and the oil will stay cleaner for longer too.

Cheers Col...I see what your saying...what Im trying to do is stop/cut down on any oil going into the inlet manifold and reduce the smoke issue that I have untill I take off the head and do the valve stem oil seals...better still stop the initial smoke on start up without major surgery...so...If I put an "oil trap" of some description between the rocker and the air inlet that would at least reduce the oil if I had some kind of filtering in there... I know it may sound a bit whacky...keeps my mind active though ..ha ha
regards,
Steve..

To be honest Steve, I don't think you will make any difference to the smoke, unless the engine is breathing really heavily, in which case the engine is knackered.
If the smoke doesn't have a blue tinge to it, then it's not burning oil.

BTW- I build engines frequently as part of my job, especially diesels. I picked up one yesterday that will be first job in the new year.

Thats the thing Col...its not..its running really well now..just the bit of smoke on start up..and a min or so lumpy on tick-over before pulling off...Im just wanting to eradicate oil getting sucked into the air intake really as I spent hours cleaning all the gunge out when I first got the van...like I said when I first joined the group...I do tend to over do things with my motors...old habits die hard dont they... ...I know I will go through this van like a dose of salts till Ive probably renewed everything on the steering/suspension aswell...I have done it on wifes cars and my Merc....saves garage fees for many years...ha ha...