pcv hose routing question
08-04-2006, 09:24 AM
#1
pcv hose routing question Car is a 2002 WS6. The PCV hose routing was changed from the original routing. The way it is setup now, the two ports on the right valve cover go to a T at the back of the PCV valve and the left valve cover vent goes to the bottom portion of the T fitting. All valve cover vents go directly to vacuum and there is no vent for fresh air to get in to the engine. Is this one of those FREE MODS or did someone make a mistake in the hose routing? I do not recall any PCV system that did not have at least one port going to fresh air. Engine builds up quite a bit of vacuum when running. 
08-04-2006, 09:33 AM
#2
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It should come out of the back of the driver side valve cover and go into a y. Out of the y one hose should connect to the passenger side rear valve cover port while the other hose goes to the pcv valve at the front of the intake. The front port on the passenger side valve cover should be connected to the tb.
08-04-2006, 10:41 AM
#3
I guess somewhere in its life it was modified. The ports on the right side valve cover go in to one hose. The fittings on the hose look factory. There is a Y at the first port and then it ends at the second port. There is no crossover hose from left to right, as shown in the hose routing diagram. Right now I have the left valve cover port going to the throttle body fitting and I blocked off one of the fittings on the T. So now the system goes from the intake, to the PCV valve and then to the two right side valve cover ports. The left side gos to the throttle body. Took it for a ride and no build up of vacuum in the engine. Before I rerouted the hoses, there was a tremendous amount of vacuum at the engine dipstick. I will see if I can reroute the system as you call out. Sounds like it would work better that way, pulling fumes from both valve covers. Thanks for the reply.
08-04-2006, 01:57 PM
#5
I am O.K. with how to route the hoses. There is a sticker on the fender well and I have the GM shop manual. I took a good look at the parts that are still there and I believe I can get it back to the stock routing without too much jury rigging. It looks like the Y fitting was moved to the front vent of the right valve cover and the rear vent (right cover) was attached to the open end of the Y. I think I can just move the Y to the rear right vent, run a hose over to the rear of the left cover and run a separate hose from the front right to the TB. Then remove the T from the back of the PCV valve and attach the hose coming from the right rear vent. That should bring it back to the stock routing. If the parts dont fit, its off to NAPA to buy some plastic fittings and hose. Just cant figure out why someone would change the routing like this. Sure made for some great vacuum inside the engine, hope it didnt disturb oil flow.
