Corvette LS1 PCV Modification

[Silver SS]

Why do this?

Corvette and GM LS1 engines have some issues. Oil consumptions seems to be one of the most prevalent issues with LS1's. Much of this is due to the way the stock PCV (Positive Crankcase Ventilation) system is designed. This system is employed to force any positive crankcase pressure into the intake manifold. This pressure would otherwise continue to build up inside the engine. The LS1 PCV system also forces oil along with the air as it relieves the pressure in the crankcase. This is especially a problem when the car is driven hard. Vapor from the PCV system will be forced into the intake manifold. This can lead to many things from a sludge building up in the manifold to carbonization in the cylinders to blackening of the exhaust.

What I have done here is to document my attempt to perform modifications on my car. This may or may not work for you. Performing any modification on a car can be dangerous, hazardous, toxic, or deadly and is fully your own responsibility. I will take no responsibility for any damage or injury that may occur in any attempt to duplicate what is documented here. If you attempt any of the described procedures you do so at your own risk.

http://govettego.com/mods/pvc/pvcmod01_small.jpg

[Silver SS]

I decided that I would put a filter in front of the PCV valve. This reason being that the valve would also not encounter the oil that could build up and cause problems. To do this I used an line filter for a air compressor. This filter is intended to remove any moisture or other contaminates from the air. It will also remove oil from our PCV system and prevent it from getting in the PCV valve or the intake manifold. I purchased the following components in the specified quantity for this project.
(1) Campbell Hausfeld MP5138 FIlter
(1) 3/8" air hose splicer
(2) 3/8" barbed 1/4" NPT male fitting
(2) 1/4" NPT swivel connector
(1) 2 feet of 3/8"ID fuel hose
(2) nylon zip ties

The parts should cost no more than $30 and can be found at most hardware or automotive stores.

Note: I have two different color swivels because I had one already and only had to go buy one. They are identical except for color.

Tools Needed:
Hose cutter
http://govettego.com/mods/pvc/pvcmod04_small.jpg

[Silver SS]

Begin with the car turned off, the keys removed from the ignition, and the hood opened. It is preferential to have the engine cool before beginning the procedure.

From the passenger side of the engine remove the oil cap. Next lift off the fuel rail cover. This should snap right off with out much effort. Place the fuel rail cover out of the way.

Remove the wire connected to the throttle body. To do this you will need to lift the plastic tab on the connector to release it. Move this wire out of the way.

http://govettego.com/mods/pvc/pvcmod02_small.jpg

[Silver SS]

Find the PCV valve on the engine. Locate a line coming out of the intake manifold just after the throttle body. Trace this line back to where you see a wire connecting it to the block. This is the PCV valve. This valve is connected to the PCV line running along the top of the cylinder head.

The PCV valve needs to be disconnected from the PCV line. This is accomplished by just pulling it apart.

This is where the parts we bought are going to connect.

http://govettego.com/mods/pvc/pvcmod03_small.jpg

[Silver SS]

This filter is directional. It has an inlet and outlet. This is very important for this installation. There is an arrow on the filter that points to the outlet. Begin by screwing the 1/4" NPT swivels to both ends of the filter. Place a 3/8" barbed 1/4'NPT fitting on the end of each swivel fitting.

Take your 2' of hose and cut one 14" piece and one 9.5" piece from this. You want to make sure these measurements are exact for proper fitment. Once you put these hoses on the barbed fitting it is nearly impossible to remove them with out damage to the hose.

Push the 3/8" hose splicer in the end of the 9.5" piece of hose seating it fully and firmly. Push the other end of the 9.5" hose on the outlet of the filter seating it firmly. This is the end with the arrow pointing towards it.

Place the 14" hose on the inlet to the filter seating it fully and firmly. We are now ready to install this on the car.

http://govettego.com/mods/pvc/pvcmod05_small.jpg

[Silver SS]

Locate the air conditioning line that runs along the front fender just below the coolant tank. We are going to attach the filter to this line just before the exhaust insulation material starts.

Place the filter just below the line with the filter inlet towards the rear of the car and the outlet towards the front. Secure the filter to the line with a zip tie on each swivel fitting. I did not snug the zip tie down so that I could swivel the filter for inspection and cleaning.

Next reroute the hoses coming from the filter underneath the coolant line running parallel to the air conditioning line. In the picture to the left they lines are shown above for clarity. You need to reroute them before connecting them in the next step (see final inspection photo).

http://govettego.com/mods/pvc/pvcmod06_small.jpg

[Silver SS]

Now it is time to connect the filter into the system after rerouting the filter hoses under the coolant line.

Simply push the end of the 14" hose on to the PCV line at the top of the cylinder head. Seat it firmly.

Push the end of the 9.5" hose with the barbed splicer into the PCV valve and seat firmly.
http://govettego.com/mods/pvc/pvcmod07_small.jpg

[Silver SS]

Make sure you have seated all the connections firmly. I did not feel the need to use hose clamps. This is all held together pretty well and did not have clamps on the factory fittings.

Make sure your PCV valve does not slip off the intake fitting. If you cut the hose to the exact length you should not have a problem. If you make the hose the wrong length the valve can tend to slip off the intake fitting. This is bad.http://govettego.com/mods/pvc/pvcmod08_small.jpg

[Silver SS]

Take a final look at all your connections. Make sure the fittings and filter is secure. Be sure that you have all the hoses properly routed. Notice the filter lines routed under the coolant hose.

http://govettego.com/mods/pvc/pvcmod09_small.jpg

[Silver SS]

Reconnect the wire leading to the throttle body. Put fuel rail cover back in place. It should snap right back on. Replace the oil cap.

Start the engine and look for any leaks or abnormal behavior.

Stand back and admire your handy work. As you can see this modification is hardly noticeable. I tried to place the filter in an discreet location away from the heat of the engine.

http://govettego.com/mods/pvc/pvcmod10_small.jpg

[Silver SS]

Get out and drive. Check the filter regularly. You should begin to see some oil collect in the filter. This means it is doing the job. Empty the filter when it looks to have a good amount of oil in it. You should not need to clean the filter. The filter in my pictures is used and should look that way after use.

Notes: In my installation I used the swivel connectors. They are about $7 each. You can save money by using a much longer hose. I was more concerned about the quality for this job. I recommend the swivels and feel this is the best way to do it. I came to this conclusion after trying other ways. The pictures and descriptions are of a 1999 model year Also the plastic bowl the oil collects in has a sticker on it warning against using this with synthetic oils.

http://govettego.com/mods/pvc/pvcmod11_small.jpg

[4ced]

interesting stuff :up:

ive always seen flaws with the factory GM PCV systems, even back in my GMC typhoon (it was a 92 model)

but this is very useful thx silver :bigok:

[TAG]

Dude! your the man!

good stuff! But there are different ways to do the PCV stuff too! If anyone is interested let me know and I will post what I have done to the car I have in the sig.

[Silver SS]

Thanks TAG...

Please share your thought on this..