Having "gunk" build up around the Intake Maniold *PICS*

[Lunatikgixxer]

Like the title says im having gunk build up around the intake manifold again and by the throttle body.. Ive had this problem months back and cleaned it up and it slowly worked its way back. Its starting to get me to think its the intake manifold gaskets. When i had the manifold off awhile back they did look pretty crushed down.

[pajeff02]

Not sure about the gunk buildup, but you should either run a catch can and/or PCV valve on your car. Looks like you are pulling full vacuum on the hose from the passenger valve cover.

[Lunatikgixxer]

which hose are you talking about exactly? They one directly in the middle of the picture on the last picture? Going to the TB?

[pajeff02]

From the rocker cover to the throttle body.

[2002ssslp]

Go with the PCV valve first and if that does not work then go with the catch can.

[Mr_Rich]

Look at the picture closer. The hose from the valve cover to the TB is atmospheric pressure. The vacuum port is capped just underneath that hose. On my LS6 that port has a hose that goes to the baffled LS6 valley cover PCV port. It doesn't look like you're running PCV on your engine.

[Lunatikgixxer]

My tuner set that hose up like that... The vaccum is underneath it, capped off. Is that hose set up wrong?

[2002ssslp]

Yes, it is wrong. I just looked at mine and that port is for PCV. That IS your problem.

[Firebirdjones]

I'd say these guys nailed it. If your tuner plugged that port for the PCV, it makes me wonder what he did with the rest of it. Because it would have a line that T's and runs to the back of both valve covers. Did he plug all that too??

You need some form of crank case ventilation, whether it be with the PCV or open valve cover breathers. Without it you get a mess like you are having. That pressure has to go somewhere.

[Mr_Rich]

The top hose is correct. That is the way the factory set it up. The capped off port is a problem. PCV doesn't really cost you anything in HP; it's just a controlled air bleed sucking fumes out of the crankcase. On my '98 they used a hose (including the PCV valve) from the driver side valve cover port running on the back side of the engine and then along the pass. side of the manifold to that capped port we're talking about. It's a lot of extra plumbing. On my LS6 the plumbing is greatly simplified. The PCV port is part of the valley cover and connects a small U-shaped hose to that capped port. Check out the LS6 valley cover mod...

[Firebirdjones]

Yeah.
Since he doesn't have the LS6 valley cover he is going to need all that factory plumbing in the mean time, or run a bunch of hose. I just wonder what his tuner did, remove it all? Did he cap the back of both valve covers where the original plumbing went?

Personally I'd just run a breather or two and call it done. Then you can do the LS6 valley cover mod later when time and money allows.

[Lunatikgixxer]

The back of the both covers have a hose running and dumping down underneath the car... How should i set up that hose going to the TB? Put a PCV valve in it?

[Firebirdjones]

The back of the both covers have a hose running and dumping down underneath the car... How should i set up that hose going to the TB? Put a PCV valve in it?

Really? Wow, I'd follow those hoses and see what they are doing. They are supposed to "T" together and then a single hose runs up the passenger side of the engine and right before it connects behind the throttle body there is a PCV valve. GM originally used plastic tubing for this that was covered in foam for some protection.

Are those hoses just left open and dangling in the back? Judging from your issue of having a film of oil pushing through your gaskets, I'd bet those hoses probably have been plugged and just left to hang there. If they were open hoses, then you would have crank case ventalation, although it not the way to do it.

[pajeff02]

Agreed. You need to draw filtered air into the engine, not just have an open end hose dangling underneath the car. Just for comparison sake, her is a pic of the factory PCV hose setup:

[Lunatikgixxer]

Theyre open FBJ. This is how i have it set up! Without the catch can though and without blocking off the rear of the passanger cover....

[Firebirdjones]

Well it's venting then, but like Jeff said, they should be filtered. I'd either hit GM up for that factory PCV line that Jeff posted, or at least for a quick fix "T" those hoses together, run a single line up to the throttle body and stick the PCV back in it.
If you don't want to do that you can at least run some small breathers in those hoses. I think they may even make breathers for LS valve covers just for some one that wants to eliminate the PCV and hoses.

Without those hoses going to the intake, you won't need a catch can because there aren't any oil vapors to catch before it enters the intake, you are assentially releasing it into the atmosphere at this point.

[Lunatikgixxer]

ok i got cha... So still just leave the vacuum capped off correct?

[Firebirdjones]

ok i got cha... So still just leave the vacuum capped off correct?

If you plan to vent to atmoshere, then yes, keep the vacuum port capped off.

[Lunatikgixxer]

how do you guys have yours set up? Do you have a diagram?

[Firebirdjones]

There is probably a diagram out there somewhere.

I run the factory tubing setup that Jeff posted a picture of on both of my 4th gens, but with a catch can before it goes into the throttle body.

It simply plugs into the back of both valve covers, and "T"s together (as you can see in the pic) then it runs up to the throttle body with a PCV inline.

For extra venting you can run a breather in place of the oil fill cap. There is one sold that is specifically for the LS engine and fits great. I ran one for a while.