oil in intake manifold and on throttle body????

ruthless_mx3 · Post by **ruthless_mx3** » January 28th, 2004, 7:06 pm

I took my throttle body off today to discover an oily, greasy coating on the back of the tb and all over in the intake manifold. what could be causing this?
I noticed a tube connecting to the intake between tb and vris that goes across the front valve cover and then into it. What is this for?
thanks

IanL · Post by **IanL** » January 28th, 2004, 7:23 pm

PCV (Positive Crankcase Ventilation) System. Blowby gases (typically carrying oily vapour - that's where your residue comes from) are admitted to the inlet tract (when the PCV Valve opens) to be burnt in the cylinders.

[ January 28, 2004, 06:25 PM: Message edited by: IanL ]

ruthless_mx3 · Post by **ruthless_mx3** » January 28th, 2004, 9:52 pm

the pcv valve is on the top of the valve cover and enters the manifold after the tb. Theres another hose that goes from the front of the valve cover to in between the tb and vris/air filter. It also has an oily residue coming out of it. Is this also a part of the pcv system?

[ January 28, 2004, 08:53 PM: Message edited by: ruthless_mx3 ]

dragonmxer · Post by **dragonmxer** » January 29th, 2004, 12:05 am

is there anyway to make it stop cuz mine does it too

bluebullet · Post by **bluebullet** » January 29th, 2004, 12:12 am

yes there is but apparently it is illegal
they look like smaller air filters one goes on ur intake and the other goes on ur engine(no tube thing between them)....more HP but illegal!

IanL · Post by **IanL** » January 29th, 2004, 9:43 am

Originally posted by ruthless_mx3:
the pcv valve is on the top of the valve cover and enters the manifold after the tb. Theres another hose that goes from the front of the valve cover to in between the tb and vris/air filter. It also has an oily residue coming out of it. Is this also a part of the pcv system?

Yes, it is. However, the way the system should work, should, in my opinion, prevent the oily residue coming out of the second hose mentioned (the fresh air supply hose).

This is why: There is normally a pressure drop across the throttle; i.e. pressure is lower (or more vacuum, if you prefer to think that way) downstream of the TB. So, when the PCV Valve opens, the airflow should go from high to low pressure; i.e. from the fresh air supply hose, through the camshaft chamber and the PCV Valve and thence to the IM, downstream of the TB. If it happens this way, the oil should not clog the TB.

If you unplug the PCV Valve from the cover, it should rattle. If not, it's stuck. If you unplug it with the engine running, you should be able to feel a vacuum. If not, it, or the hose, is blocked.

Just a guess, but if the PCV Valve is stuck, could the fresh air supply hose be sucking the stuff out of the engine?

Alternatively, Chilterns says: "If air pressure, and oil or sludge is present at the end of the fresh air supply hose, the engine has excessive blow-by, and cylinder bore or piston ring wear".

[ January 29, 2004, 10:20 AM: Message edited by: IanL ]

ruthless_mx3 · Post by **ruthless_mx3** » February 2nd, 2004, 12:22 am

OK so, since i have no emissions tests, remove pcv valve and replace w/ filter and cap the nipple on the manifold where that tube goes. Now what about the tube prior to the TB, what do I do with that?

ruthless_mx3 · Post by **ruthless_mx3** » February 2nd, 2004, 12:37 am

oh yeah
my pcv valve does rattle and my car has 120000miles on it so that could be part of the oil problem

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oil in intake manifold and on throttle body????

oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????

Re: oil in intake manifold and on throttle body????