91sbcamaro

iTrader: (3)

i jsut took off the intake ducting and air filter to find oil in the throttle body? I was planning an overhaul on the engine but do you think i need to do a full rebuild now? what exactly could the problem be?

thanks

HSV-GTS-300

Valve guides and seals.

6L chevelle

I Agree, valve seals and guides. A little oil residue isn't terrible, but less than a teaspoon

SSTYCOON

iTrader: (2)

Did your car use oil?
I'm thinking PCV valve

91sbcamaro

iTrader: (3)

oh there was more then just alittle oil in there. so im thinking its somthin major..how would i check the PCV?

Buckshot

Welcome to the wonderful world of the LS1/6. The LS1 PCV setup sux and the one on the LS6 isn't much better. This is a well known LSx weakness. Many of us run oil catch cans to minimize the problem. Some guys make their own from a Campbell-Hausfield air compressor filter and tubing while others buy an aftermarket can and place it inline with the PCV valve. Mine catches most of the oil, percipitating it out of the vapor headed for the intake. I also swapped in the LS6 PCV valley cover and trashed my LS1 setup just for kicks. AMW makes a very nice catch can although it's expensive at ~$160. The C-H diy version is less than $20 with parts from Lowes. Btw, this is typical - I've worked on lots of LS1's and the intakes looked at least as bad as my '02.

My intake after only 2900 miles after I bought it.


Typically the amount of oil after ~800 miles.

SSTYCOON

iTrader: (2)

The PVC is right by your TB on the passenger side, GET the truck PCV valve, some same its better, it might slove your problem

jaredm

pcv valve would be the most the likely candidate. I had the same problem and come to find out there are filters you can get to keep that from happening.

racecar

I just pulled my throttal body and noticed the same oil in the intake of my LS6 motor.
This new motor has 4-5% leak down, I think it is blowing by the rings.
QUESTION FOR BUCKSHOT: With a catch can and a K&N filter on the can, does oil blow out of the can and make a mess in the engine compartment???

Buckshot

racecar, my catch can routing is a closed loop system that is in-line with the PCV system. The line goes from the PCV outlet on the valley cover to the catch can and back to the intake manifold inlet. I'm not using a filter at all - simply the catch can to precipitate the oil out of the vapor coming out of the motor before it hits the intake. Some guys do use breathers/filters in the valve covers. I have a couple I have considered using but had heard they often leave the oil film under the hood so haven't tried mine yet.

Here's a shot of the Metco breather which displaces the oil fill cap and the K&N in place of the LS1 PCV tubing in the driver's valve cover.


You can see the two black catch can hoses running from the valley cover and intake to my catch can which is next to the passenger side of my radiator shroud.


The catch can (before changing to the black hoses).


The catch can when I emptied it while doing the Vararam.

racecar

Cool Deal. The can is just in one port and out the other, both on top? Is there any baffle inside the can, or just an empty can? I'm going to try that, I have not had good luck with breathers on the valve covers. Tried that when I was 18 on a small block 302, spent the next day with the pressure washer on the firewall.

Buckshot

Correct. My GReddy has no baffle in it but the AMW can has a small perforated plate that acts as a baffle. Some folks have added some sort of medium similar to a plastic scrubbing pad to the GReddy and other cans to act as a larger surface area for oil condensation but I haven't heard if that helps or not.

Here's a PDM version of a catch can . . .


. . . and AMW's (these come in blue, red, black and clear anodize).


And, of course, there's always the C-H air compressor filter method you could try although that one needs to be monitored more frequently as the collection chamber is quite small.

racecar

Excellent, Thanks for the great pics. I'm ready to build one now.

carguy1985

i put a edelbrock intake manifold on my camaro once (1978) and i guess it ended up being a little bit cocked along the heads, and i was sucking oil into the intaike manifold runners and blowing alot of smoke out the back. Maybe bad seal.

1BAD_Z28

not to hijack the thred or anything, but i am having the same problems with my car. me and my cousin took off the manifold and there was alot oil in all the intake ports except the back two. the car was running real lean at the time, it need alot of fuel like 10 in the base and 12 in the WOT. does this sound like the rings are fried or do you think its the pcv system???? any thoughts would be very helpfull
thanks
Ryan

racecar

1BadZ-28 I'm thinking that it is all PCV related. Check the leak down to confirm that your rings are OK. My LS1 with 18K had 2-3% leak, my new LS6 has 3-4%. PCV is a necessary evil. I consider it a huge vacuum leak that does your tuning no good. But, you need to evacuate those fumes from the crankcase. That's why the NASCAR guys run a 5 stage oil pump, one stage is crankcase vacuum. If you are driving your car every day (not always getting up to temp) you really need a good PCV system. I'm going to experiment with a closed loop can like Buckshot has, that looks like the ticket..

91sbcamaro

iTrader: (3)

how do you test the leak down of my LS1?

~sorry if this is a stupid ?

c5dream

iTrader: (1)

Oil in the intake is not from worn rings or vavle guides. This is common on the LS1 engines they revised the PVC system on the LS6. Best way to reduce this on LS1 is to either convert to LS6 type PVC system or purchase a catch can.

racecar

C5 Dream; I have LS6 valve covers and valley cover and it still is oiling the intake??
That 's with JE pistons and rings, they have more end gap for racing, so they may be allowing more blowby the rings until the engine is hot. Next step, build a can!!

91SBCamaro; A leak down test is similar to a compression test. Pull out the spark plugs, turn the motor to TDC, screw in a leak down gauge; plug in compressed air. It has two gauges, one measures the incoming air pressure (100psi) the other measures the air pressure in the cylinder, let's hope that is 97 or 98, that would be 2 or 3% leak. The gauges are about $100. It works good.

c5dream

iTrader: (1)

Piston rings are anything related to piston chamber has nothing to do with oil in the intake. Air is sucked through the intake nothing gets blown back out the intake (well unless you have a intake backfire).