Unknown vacuum hose on D16A8 eh9 Si

**EG52NV** · 23-01-2010 06:05 PM

Hey Guys just this afternoon I was doing an engine oil change and when I went to remove the oil filter, I noticed that above it, there was 10mm thick vacuum hose which was freely sucking air but the end of it wasnt connected to anything. Neither could I find any female connection that it should have been connected to.

Upon further investigation I have traced the start of the hose back to the engine block, below the throttle body runner, on the timing belt side.

I've tried capping it off but it seems to cause the car to idle at 300rpm which I guess can only mean 1 thing.. it's supposed to be connected back to somewhere in the throttle body so it can suck air, but where?

Anyone have any idea? oh and if I just leave it alone to suck atmospheric air, car idles like normal at 800 rpm.

**HwyStar** · 23-01-2010 10:40 PM

Post up a picture so we can help you.

**beeza** · 24-01-2010 09:32 AM

Yes a pic

**japcollector** · 24-01-2010 12:12 PM

Prob the ignition hose

**aaronng** · 24-01-2010 12:32 PM

It might be the hose from the PCV valve. If it is, there should be a hose barb connector on your intake manifold (could be underside) which is missing a tube.

**EG52NV** · 25-01-2010 01:10 PM

I thought the pcv hose comes from the top of the rocker cover back into rubber intake arm?

Hmm how am I going to take pics it's such a tight squeeze, ok will try get pics tonight..

**aaronng** · 25-01-2010 01:35 PM

Originally Posted by EG52NV

I thought the pcv hose comes from the top of the rocker cover back into rubber intake arm?

Hmm how am I going to take pics it's such a tight squeeze, ok will try get pics tonight..

No, the one from the top of the rocker cover is the rocker cover breather hose and it connects back into the intake arm.

The real PCV goes from the engine block to the metal part of the intake manifold.

**beeza** · 26-01-2010 11:09 AM

That's the only thing I thought it could have been too..

If you pull that hose out from the bottom there should be the PCV valve on the end of it (or still in the hole you pulled the tube out from).It's a plastic valve with a ball bearing in it.Give that a good clean up and put it back.

Just remember where you pulled the hose/PCV from as you cant see it,so just feel it out.Use a torch!

Unclogging the PCV will help your car breath better.