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Old 12-03-2010, 11:54 AM   #1
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Default blowing oil out the valve cover breather ports

I asked in my build thread, but haven't gotten much of a response, so I figured I would start a new thread.

I have a new fully built motor that is blowing a significant amount of oil out the valve cover breather ports ( went for a 4 hour drive and my once empty catch can was overflowing). The engine was broken in on the dyno, and has approximately 4 tanks of fuel run through it. I am running a 323 GTX pcv valve on the intake side. Here's a current pic of how the lines are routed to my catch can:
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the motor was built by a race shop with all new components, and the head and block were checked for cracks. It has an OEM headgasket. The baffles in the valve cover are all in place, and I sealed them with rtv upon installation.

I did a compression test and got 218-218-220-220 (cyl 1-4) on a warm engine (I have low comp. pistons and mild cams). The car doesn't smoke, it's making good power, it's not overheating, and oil pressure and temperature are normal.

Does anyone have any other ideas as to what the cause might be?
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Old 12-03-2010, 02:32 PM   #2
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Your PCV valve is serving no purpose in this configuration other than acting as a restrcition because you have defeated the PCV system - get rid of it or drill it out.
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Old 12-03-2010, 02:42 PM   #3
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Your PCV valve is serving no purpose in this configuration other than acting as a restrcition because you have defeated the PCV system - get rid of it or drill it out.
Funny you should say that. I just removed it and replaced it with a fitting, went out for about a 2 hour drive, and the can was I would say 1/4 full.
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Old 12-03-2010, 03:00 PM   #4
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Your PCV valve is serving no purpose in this configuration other than acting as a restrcition because you have defeated the PCV system - get rid of it or drill it out.
Moronic post is moronic. The PCV is closed at 100kpa (above that is for another thread considering he does not have a hose plumbed to the intake, which is good)
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Funny you should say that. I just removed it and replaced it with a fitting, went out for about a 2 hour drive, and the can was I would say 1/4 full.
I just did a similar "mod" for my breather and had the same result. You want to plug the passenger side port all together and use a large port on the driver's side. The passenger side breather pick-up is at the back of the valve cover, on the same side that feeds oil through the head. Oil is most likely pooling on the passenger side of the valve cover, but when accelerate the oil is getting picked-up and pushed through the hose. The pick-up for the driver's side port is between plug 3&4, so no oil is pooled back there to suck up. This is only a hypothesis.

Pull off that valve cover and have a look for yourself. Plug that port and see what happens, I'm testing the same thing with one pick-up on the driver's side this weekend.

If the piston/ring seal is bad a leak-down test will indicate this failure. Bad valve guide seals are still a guess but unlikely if you're not burning oil..."unlikely" is not absolute.
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Old 12-03-2010, 03:34 PM   #5
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Wouldn't good compression test results tell me the rings are fine?
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Old 12-03-2010, 03:40 PM   #6
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Wouldn't good compression test results tell me the rings are fine?
Yes.
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Old 12-03-2010, 04:08 PM   #7
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I should also note that I have a 99 valve cover. When I was ***** footing around the track on left turns I had no problem, when rhomping the car on the lefts it went ugly, fast.
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Old 12-03-2010, 04:19 PM   #8
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with the pcv in place (like in the pic), from the looks of the lines it seems the majority of oil was coming from the driver's side port anyways, so I don't think your theory is 100% for this situation
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Old 12-03-2010, 05:17 PM   #9
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Quote:
Originally Posted by mighty mouse View Post
with the pcv in place (like in the pic), from the looks of the lines it seems the majority of oil was coming from the driver's side port anyways, so I don't think your theory is 100% for this situation
Do you have a MSM PCV? If not then that's a problem too because you'll pressurize the system then. Try capping the passenger side off completely and see what it does.
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Old 12-03-2010, 06:25 PM   #10
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No, I have a 323 GTX valve.
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Old 12-03-2010, 06:54 PM   #11
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I'd like to know what would happen if you were to take both the breather and the PCV hole and ran them to a catchcan...and then run a vacuum source to that catchcan (pre turbo) to it's not VTA anymore.
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Old 12-03-2010, 11:15 PM   #12
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I'd like to know what would happen if you were to take both the breather and the PCV hole and ran them to a catchcan...and then run a vacuum source to that catchcan (pre turbo) to it's not VTA anymore.
Did you read my previous post? The left side will puke oil.
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Old 12-04-2010, 02:55 PM   #13
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I did, but do you not think there might be any difference if the valve cover has vacuum on it rather than the positive crank case pressure coming up? It has been a minute since I have seen the underside of the valvecover and where the passages are.


Oh **** it. Fill both holes and put fittings on TOP of the baffles...coming straight up out of the VC. That should sove any sloshing problems
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Old 12-04-2010, 03:07 PM   #14
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Quote:
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I did a compression test and got 218-218-220-220 (cyl 1-4)...
Off hand, those seem like very high static numbers for a low compression engine. How low is it? I was looking at high 180s on a warm stock healthy 1.6.
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Old 12-05-2010, 10:22 AM   #15
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This just in...I need an air/oil seperator because oil is blowing through the filter, but only milky vapor crap is collecting in the can.
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Old 12-05-2010, 07:44 PM   #16
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off hand, those seem like very high static numbers for a low compression engine. How low is it? I was looking at high 180s on a warm stock healthy 1.6.
9-1
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Old 12-05-2010, 07:53 PM   #17
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Yeah 220 is pretty darn high IMO, but I've seen 205 before on a very healthy engine.

Don't know.
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Old 12-05-2010, 08:04 PM   #18
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Ive read in the catch can thread that Hustler was going to try (idk if he has yet) just running one line, maybe you could try this yourself?

Hustler- any luck on trying 1 line to the catch can?

Doppel - do you have any pictures of your catch can routing?
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Old 12-05-2010, 08:13 PM   #19
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I had good results yesterday. I'm making cappuccino in the can bust still blowing a very small amount of oil THROUGH the filter. I didn't have to add oil all day but I'm going to stuff some steel wool in the neck of the can to hopefully catch that oil.
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Old 12-05-2010, 08:35 PM   #20
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I had good results yesterday. I'm making cappuccino in the can bust still blowing a very small amount of oil THROUGH the filter. I didn't have to add oil all day but I'm going to stuff some steel wool in the neck of the can to hopefully catch that oil.
What kind of can are you using? Which line going to the catch can did you delete, the PCV line?
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