View Full Version : curious why,PCV vents different?

johnny kannapo
05-29-10, 12:54 AM
So the rear head on this 96' has a 3/8 vent plumbing & the front head has 1/2 vent plumbing and the have separate ports one at the TB backside & one nearby but on the plastic intake.

Are these ports separated for some reason or do these separate ports directly connect? I see that the 1/2 line is connected to the TB with the coolant flow from the steel flex line close by.

I could not find any vacuum diagrams for this PCV system.

05-29-10, 09:59 AM
If I am understanding you correctly I think one is the PCV line (to the manifold) and the other (at the TB) is the fresh air supply. You lost me with the "coolant flow" though. These lines should have nothing to do with the cooling system or coolant.

05-29-10, 10:26 AM
The PCV line on the TB is on the air filter side of the throttle butterfly and connects to the front cam cover, the PCV valve is in the rear cam cover and that line connects to vacuum on the intake manifold.

The PCV (dirty air) hose connection location is why the pre-2000 TB's get so much dirtier that the newer models.

His TB is heated by separate coolant lines - not internal crossover passages as in 2000+. The TB's are heated to prevent icing in the bore from venturi effect downstream of the butterfly.

johnny kannapo
05-29-10, 12:33 PM
There is a steel flex-tube that goes from the TB to near the thermostat. http://i826.photobucket.com/albums/zz183/billytheshoe/71f8ef5d.jpg

johnny kannapo
05-29-10, 12:36 PM
These are the vacuum ports the smaller being the rear head vent. The batt is low & the camera didn't focus right. http://i826.photobucket.com/albums/zz183/billytheshoe/b8fc4285.jpg

johnny kannapo
05-29-10, 12:42 PM
I get it now. There IS a pcv valve in the rear head.

I knew it was heated I just never looked, it seems odd they chose to use a steel tube such as this.

05-29-10, 10:39 PM
you have plastic fuel lines? did you miss out on the recall?

05-29-10, 10:53 PM
He's not talking about fuel lines - this is about the PCV plumbing.

Unfortunately not all of the composite fuel rails were subject to recall, and a fair number of fuel lines have an engine compartment flex section of stabilized black Nylon, not plastic.

His pictures DO indicate that he might want to look into the recall for his particular fuel rail: year/VIN.

05-29-10, 10:57 PM
The recall was for '95 - '97's. Being a '96 I'm sure Johnny's was included. Get thee to a dealer before you have a "thermal event".

johnny kannapo
05-31-10, 12:28 PM
I haven't considered the recall and was unaware the it hadn't been done. I will certainly look into it. http://i826.photobucket.com/albums/zz183/billytheshoe/dd9f450c.jpg

Mark C
06-01-10, 01:14 PM
The metal corrogated tubes are EGR tubes that connect to the exhaust manifolds, the heater tube is the black rubber and plastic line below the metal one, on this engine it looks like the purge line is connected to the throttle body for heat, or it has a couple of really tight 90 degree bends as it goes around the dog bone support bracket.

johnny kannapo
06-07-10, 11:32 AM
I haven't considered the recall and was unaware the it hadn't been done. I will certainly look into it. http://i826.photobucket.com/albums/zz183/billytheshoe/dd9f450c.jpg I am being told that this fuel rail pictured has been replaced in 2004 and there are no open recalls.

Can this be right?

06-07-10, 08:03 PM
Nope - that's original crappy lines that sometime leak and cause fires - the metal replacement looks like this: