V8 Supra Builder

iTrader: (36)

My setup:
2003 LM7 5.3L Avalanche motor w/ 30K miles in a 1988 Supra (since it is a truck motor, I'm posting here vs tech), car intake. No mods other than block hugger headers. EGR/AIR deleted via HP Tuners. Manual fuel pressure regulator w/ vacuum reference (car was going to be turboed but ran out of room for turbo). All vacuum accessories (evap, cruise actuator, fuel press reg, heater control valve) except the brake booster draw from the fitting on the driver side of the intake. The brake booster is hooked to the port on the back of the manifold.

My crank venting is stock and properly routed as far as I know (I didn't have a truck to look at when I did this)- the passenger valve cover hose goes to the fitting on that side of the intake, and the driver side w/ "PCV" is routed to the rubber elbow in front of my throttle body.

The motor is not using any noticeable amount of oil, but I only have about 500 miles on the setup since I don't drive each car very much.

The problems:
1) After driving a while (15-20 minutes), I get a loud whistle- it sounded like a belt squealing, but continued for a few seconds after shutting the motor off.
2) Occasional puff of gray/white smoke when starting (enough to see in the rear view mirror).

What I've done-
I tested vacuum lines by removing & replacing one at a time. When I got to the passenger valve cover hose to the intake, the whistle went away. Ditto the driver side. I found the "PCV" was just a metal fitting with a really small (1/8" or so) hole in it. When I pulled it out with the motor running, I got a huge "whoosh" of air. I enlarged the hole one drill size at a time up to about a 5/16 and I no longer have the noise. Is this detrimental to the motor?

Since the smoking was totally random, I'm not as concerned about that. It does not seem to do it as often or as bad as at first.

I've been doing some searching & reading here & most of what I've seen for the PCV setup is related to forced induction, which does not apply to me. I'm running catch cans on my turbo vehicles w/o this issue (I did have a lot of crankcase pressure on my BMW w/ the 2005 L33 5.3L, but this was solved with some hose re-routing and an unintentional oil pan vent & breather), and can do so if need be for this motor, but I'm hoping it won't be.

I've never seen this problem with the 2005 L33 in my RX7 and have a lot more miles on it than the Supra.

Thanks for any help.

ZZebes

iTrader: (10)

Did you use or cap the vacum fitting on the top of the intake manifold

and that drivers side fitting should be vented behind the TB to see vacum

V8 Supra Builder

iTrader: (36)

Not sure which fitting you mean by on top of the manifold. I had a large opening for EGR there & it has been plugged.

I'd have to tee in the driver side hose to the other stuff to locate it behind the TB. I only have three vacuum ports on the manifold, one on each side and the rear for the brake booster, plus there is a fitting on the TB on the pass side but it does not seem to have any vacuum and has been capped.

I've attached a diagram of my setup.

Spoolin

iTrader: (8)

pics of the car and engine bay?

V8 Supra Builder

iTrader: (36)

Fquick Supra page
Engine bay:

budhayes3

iTrader: (19)

My PCV whistled after I installed my AMW catch can. I removed the fixed orifice PCV and installed the old spring and plunger style and the whistle went away. It was loud enough that I heard it in the cab with the radio off. White smoke indicates coolant, or it could just be condensation in the exhaust which is normal.

*EDIT* I just looked at your attached pic and it appears that something's amiss with the vacuum routing. The PCV should use manifold vacuum after the throttle body. From what I remember, the car intake gets it's vacuum for the PCV from one of the ports behind the throttle body? Maybe someone with a Fast or LS6 intake can post some pics or you could search the "Show and Shine" section for some engine bay pics. I'm sure that someone here knows the vacuum routing of the car intake, alot of guys have done the swap...

V8 Supra Builder

iTrader: (36)

OK, thanks for the advice. I need to look into how I can re-route the lines.

James B.

iTrader: (1)

The crankcase pressure should not rise or fall beyond outside air pressure. There has to be a fresh air inlet. The fitting you have in the elbow in the elbow right before the throttle body should go to the valve cover fitting with no checkvalve or orfice in it. That should be an open tube right to the valve cover. On the other side of the engine is where the PCV valve (or orfice) should be, and that is a smaller hose that should be connected to manifold vacuum. The PCV fitting draws air from the engine into the intake, but the other larger fresh air hose replaces that air with fresh filtered and metered air at atmospheric pressure. Because the air going into the engine passes through the MAF, the air entering the manifold through the PCV is being accounted for.

V8 Supra Builder

iTrader: (36)

OK, it sounds like I reversed the valve covers then. I don't think I ever had these off due to not replacing the springs, though. I looked at the L33 motors, and they are setup a little differently. There is no PCV type fitting on either cover, and on the NA motor, the pass side goes to the angled fitting on the top pass side of the TB, and the driver side to where I have my accessories plumbed.

I will modify my diagram to show what I did in line with this advice.

Thanks for the info.

EDIT
Pic attached, too many lovebugs out now to test it, but I will let you all know if this worked.

Thanks again.

budhayes3

iTrader: (19)

This looks right to me...on my truck the port on the throttle body goes to the pass side valve cover, and the pcv is on the driver's side, connected to a port on top of the intake. I guess that the car intake has a port on the pass side? Just curious, which intake are you using? (LS1 or LS6)