Decided to check my crankcase filter/oil separator today and noticed the hose for it has cracked since i was under the hood last.

It IS along the seam and it IS the original so this could just be from a long hard life, but I am wondering about excess pressure as well.

Without looking into it much I have heard the PCV system in the XJS is a bit odd. Looking at the routing does it not just vent the LH head to the intake manifolds?? How does the pcv valve work in this setup? Is it just a one way check valve? Does it get dirty and allow pressure to build (if so can I clean it?)
i apologise as I am not very versed in ventilation systems
thanks all

 

soonest I can get one of these is the 21st...but i have school and work until then. I guess it is good the crankcase air is being pushed out and not being pulled in...but I can't think of a solution to prevent debris entering through the broken filter cover....will the filter itself help at all?

Very minute amount of dirt and debris can cause engine damage...

 

It IS an odd system....I can't remember the details but I'm quite sure it's all in Kirby's Book. Or someone here might remember how it works and chime in.

Took me a little time to get my head around it but it's been years since I gave it any thought.

Cheers
DD

 

Doug's right - the PCV "system" is described in detail in the book, pp 51-53. The system is supposed to create low pressure in the crankcase and circulate gasses back through the intake - stuff is supposed to be pulled out through that opening, not in. Whether it really works is debatable, but I think its not going to be sucking dirt into the crankcase. Unless its a gaping hole you probably don't need to worry much.

 

I don't have much choice but to drive it, Im not risking RTVing it and RTV falling in. knowing it is pushing out it definitely comforting, but it still sucks.

There doesn't seem to be many manufacturers of that cover/boot/hose over the crankcase filter. there is only one on amazon.

The system works fine, the alternative is to dump it out on the ground or create blowby, I just haven't serviced it since i got the car

 

PSA time!!

I have heard LITERALLY NOTHING about the PCV system mentioned in XJS maintenance, it is ALWAYS the cooling system, then general tune up stuff and rubber.

I have heard MULTIPLE times and even made a thread to ask what "normal" oil pressure was. I have been told by many people that idling when warm their car bottoms out on the gauge. Obviously this isn't zero oil pressure because the engine is running or even too low because the light is not on.

HOWEVER. The crack in my PCV system allowing the crankcase to vent straight out of the filter has resulted in a HUGE increase in oil pressure. My car has gone from bottom of the gauge hot to the 1/4 mark!!!

Based on the gauge itself this means the idle oil pressure has gone from probably 8-10 up to 20 or 25 psi!!!


so this is something i think everyone should check on since everyone seems to agree pegging the bottom of the gauge is "normal"

Just disconnect the PCV hose before the air filter (assuming your crankcase filter is clean) and see if your idle pressure changes