my father has a '31 chevy 2dr coupe with a fairly new LT1 in it. the old one blew up on us and we had bought this one a while back for insurance lol. well tonight we got it running and it purrs like a kitten but has a decent amount of steam coming from the valve cover breather. it has been sitting for a while so i guess its just steam from moisture collecting... i hope. im not too worried about it but my father wants a second opinion before we put it away for the winter. THANX

 

Steam coming from the breather may indicate the PCV valve is not working. Have you checked it?

 

ok theres a breather on the passenger side valve cover i believe is the PCV valve cuz its got a tube goin straight to the throttle body. theres also another on the driver side, thats the one that has vapor coming from it. now the two breathers are billet pieces so if the PCV one is bad is there a way to rebuild it or do we need to buy another? or am i completely off on these being PCV valves.

 

To hijack this thread whered he get those wire guides? they look awsome!

 

http://www.yogisinc.com/results.cfm/...07/product.htm

ne body else on the PCV problem?

 

They are not the PCV valves... it isn't in the valve cover. The stock PCV system has the PCV valve in the middle of the intake manifold on the passenger side. Photo from Shoebox:



That picture is a 95. On the 95-97 engines, the vacuum source for the PCV routes to a port on the intake manifold, underneath the throttle body. On the 93-94 LT1's, there is a U-shaped tube that loops immediately back into the intake manifold. In this photo, the U-shaped tube is partly hidden by the brake booster vacuum line:



Appears yours may have the 93-94 version.

Then there is a rubber hose that connects a nipple on the passenger side of the throttle body to the passenger side valve cover. That supplies filtered air that has passed through the MAF sensor, and up through a port in FRONT of the throttle body blades. Hence, no vacuum applied to that line. That air goes into the valve cover and is pulled through the crankcase and up into the lifter valley, through the heat shield on the bottom of the intake manifold, and through a passage to the PCV valve, where engine vacuum dumps the air and crankcase vapors back into the intake manifold.

This shot shows the stock routing of the air supply line from the TB to the valve cover:



If you added a breather on one or both valve covers, you have "opened up" the closed PCV system. If your engine runs an MAF sensor, you have created a small "vacuum leak", but its small enough that the long term fuel corrections should be able to compensate for it.

You need to pull the PCV valve out and make sure its not plugged up, or a spring broken. Then make sure there is a vacuum being applied to the exposed end of the PCV valve by the hose that connects to it.

If you have vapor coming out of the breather, is means the PCV system is not pulling all the blowby out of the crankcase. The gasses that blow by the piston rings include a lot of water vapor, and that needs to be pulled out of the crankcase, or it will condense and muck up the oil.

Nice setup on the 31 Chevy. I'd like to see some more pictures of it.

 

iceman117 in your second picture the PCV valve is located (and just barely out of sight) below and slightly to the LEFT of the brake booster-Intake connection.

(Edit: Typed right instead of left)

 

dont want to jack the thread but...

Inj- you mentioned that having a breather on a closed pcv system will affect you if you have a MAF, what if your car is speed density? just wondering cuz i have a breather on pass. side valvecover, and on the driver side of intake i plugged the vaccum line and left the pcv valve open. i have less than 200 miles on my motor and my breather is full of oil, and the pcv valve expels vapors. only reason i did that was because i dont want oil getting into my TB or into my intake, valves, and spark plugs. dont know if it makes any sense?

 

ok here it is from the START... originally there was a 1994 corvette LT1 in her. one night the optispark let go and that triggered many other little things to roar thier ugly little heads. so with all this gone wrong and the motor going low on oil pressure... we happened to have bought a 1996 CAMARO LT1 with a T-56, so we decided to replace the tired 94 corvette engine with the 96 camaro engine. everything went very well while installing and it looked awsome. we started it up and it ran beautifully, great oil pressure, good exhaust note, but the valve cover breather had some vapors leaking from it.

this is the point where i contacted the great camaroz28 forums for some answers lol.

my father backed her out of the garage this afternoon and had her running for a while checking fluids and all when he realized when he revved it up blue smoke came from the tailpipes. blue smoke is never good and it worries both of us. could the swap of the intake manifolds cause a mix-up in pcv lines? could a mix-up in the pcv lines cause her to burn oil?

i will work on some more photos of the car and setup of the intakes.

again THANX a lot

 

i just went out to the garage to take another look at it. the PCV valve has a line going to a nipple just underneath the TB into the manifold. i pulld the pcv valve and i can push the valve in and out and it doesnt feel like ne thing is broken.

i thought my father had switched manifolds but i guess not since it has a line going from the pcv to under the TB.

ok before i confuse myself ne more at this hour, i will jus take lots and lots of pictures and make a whole photo album for u guys on my photobucket tommorow.

 

Sounds like the rings to me. Hope its not though. Good luck

 

All the LT1 intake manifolds have the port below the throttle body. On the 93/94's its plugged with a pipe plug - easy enough to remove.
Heavy vapor load in the crankcase can be the result of excessive ring blowby. At this point, given the blue smoke, it might be worth doing a compression and leak down test to make sure the rings are OK. If they are OK, look for something putting oil into the system, which could include problems with the PCV system, worn valve guides, leaking intake manifold gasket, etc.

 

It does not cause a problem on the speed-density cars, because the system does not rely on the mass air measurement from the MAF. It calculates the mass air flow from a number of factors, including the intake manifold pressure (MAP), and MAP would reflect the flow through the PCV vacuum port into the manifold.

Your system is not working correctly without a vacuum line connected to the PCV valve. The key word in Positive Crankcase Ventilation is "Positive"..... the crankcase is ventilated by the cross-flow of air created by the vacuum connection on the PCV valve. Without the vacuum being connected, the only thing that vents form the crankcase is any excess pressure. The crankcase is left full of combustion gasses on shutdown, and those gasses contain water that condenses as the engine cools down and mucks up the oil, forms acids, etc.

Since your engine is fairly new, the rings may not have seated and you may be getting higher than normal blowby, filling the crankcase and blowing out the breather and the PCV. You have to hook up the vacuum to help clear the crankcase out, and reduce the pressure builup.

The best way to avoid getting oil into the intake is to put a filter or a catch can in the line from the PCV valve to the manifold. Are you sure you put the sheetmetal baffle on the bottom of the intake? It helps keep oil out of the gasses that flow to the PCV valve. Also helps keep the bottom of the intake cooler.

 

left the baffle on the maniflod but i still wonder how the breather gets oil inside? isnt there a baffle in the pass. valvecover that should restrict it? again like you mentioned Injuneer it might be that the rings arent seated yet.

 

My engine did the same thing when it was rebuilt. I also had higher than usual oil consumption for the first few oil changes (Daily driver).