Intake Runners coated with oil (PICTURE)
06-08-2013, 02:15 AM
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Car: 1989 Iroc-Z 350
Intake Runners coated with oil (PICTURE)
Removed my plenium to clean the EGR and noticed on one side the intake runners were coated with oil while the other side was clean and dry. Noticed some smoke out exhaust on startup today as well. The intake manifold gasket was replaced by a mechanic about 3 weeks ago.
1989 Iroc-Z
pic isnt my car just as reference.
1989 Iroc-Z
pic isnt my car just as reference.
Last edited by nakota2k; 06-08-2013 at 02:43 AM.
06-08-2013, 06:44 AM
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Car: 89 GTA/90 Iroc Vert
Engine: 5.7/5.0L
Transmission: 700R4 x 2
Axle/Gears: 3.27/2.73
Re: Intake Runners coated with oil (PICTURE)
Is there a vent tube in the valve cover on that side ? Mine pops out some times.
Smoke = valve seals
Smoke = valve seals
06-08-2013, 08:48 AM
#3
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Re: Intake Runners coated with oil (PICTURE)
I was thinking the same thing. There is no oil up in the plenum (and a leak big enough to cause a mess would certainly make for lousy running). Gotta be that breather tube or oil somehow, somewhere making it's way up from the valve cover on that side.
06-08-2013, 12:48 PM
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Re: Intake Runners coated with oil (PICTURE)
Last edited by nakota2k; 06-08-2013 at 12:51 PM.
06-08-2013, 04:41 PM
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Re: Intake Runners coated with oil (PICTURE)
I can't offer you much help but it's curious in that the oil residue is in the runners that supply intake air to the same side of the intake that the PCV valve is connected to.
FWIW, your valve covers aren't backwards. You're just running two driver-side valve covers.
FWIW, your valve covers aren't backwards. You're just running two driver-side valve covers.
06-08-2013, 04:48 PM
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Re: Intake Runners coated with oil (PICTURE)
I can't offer you much help but it's curious in that the oil residue is in the runners that supply intake air to the same side of the intake that the PCV valve is connected to.
FWIW, your valve covers aren't backwards. You're just running two driver-side valve covers.
FWIW, your valve covers aren't backwards. You're just running two driver-side valve covers.
06-09-2013, 02:40 AM
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Re: Intake Runners coated with oil (PICTURE)
Because the PCV valve is sucking crankcase fumes into the intake, the vent tube is where fresh air is drawn into the engine. There is some reversion of the intake charge so if the PCV is sucking in oil it could end up in the runners. There should be no oil (or maybe a trace of oily film) in the vent tube or hose. I'd check the PCV system first. Just a thought.
Reversion: I had an old F-100 with a 390 in it that lost a valve seat in No. 2 cylinder. I found bits of the seat the No. 3 cylinder when I removed the head.
Last edited by paulo57509; 06-09-2013 at 02:54 AM.
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06-09-2013, 03:10 AM
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Car: 1991 Christine Z28
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Re: Intake Runners coated with oil (PICTURE)
The intake runners on the passenger side of the plenum feed the driver's side cylinder head; the head with the PCV valve in it.
Because the PCV valve is sucking crankcase fumes into the intake, the vent tube is where fresh air is drawn into the engine. There is some reversion of the intake charge so if the PCV is sucking in oil it could end up in the runners. There should be no oil (or maybe a trace of oily film) in the vent tube or hose. I'd check the PCV system first. Just a thought.
Reversion: I had an old F-100 with a 390 in it that lost a valve seat in No. 2 cylinder. I found bits of the seat the No. 3 cylinder when I removed the head.
Because the PCV valve is sucking crankcase fumes into the intake, the vent tube is where fresh air is drawn into the engine. There is some reversion of the intake charge so if the PCV is sucking in oil it could end up in the runners. There should be no oil (or maybe a trace of oily film) in the vent tube or hose. I'd check the PCV system first. Just a thought.
Reversion: I had an old F-100 with a 390 in it that lost a valve seat in No. 2 cylinder. I found bits of the seat the No. 3 cylinder when I removed the head.
06-09-2013, 06:26 PM
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Car: 1989 Iroc-Z 350
Re: Intake Runners coated with oil (PICTURE)
The intake runners on the passenger side of the plenum feed the driver's side cylinder head; the head with the PCV valve in it.
Because the PCV valve is sucking crankcase fumes into the intake, the vent tube is where fresh air is drawn into the engine. There is some reversion of the intake charge so if the PCV is sucking in oil it could end up in the runners. There should be no oil (or maybe a trace of oily film) in the vent tube or hose. I'd check the PCV system first. Just a thought.
Reversion: I had an old F-100 with a 390 in it that lost a valve seat in No. 2 cylinder. I found bits of the seat the No. 3 cylinder when I removed the head.
Because the PCV valve is sucking crankcase fumes into the intake, the vent tube is where fresh air is drawn into the engine. There is some reversion of the intake charge so if the PCV is sucking in oil it could end up in the runners. There should be no oil (or maybe a trace of oily film) in the vent tube or hose. I'd check the PCV system first. Just a thought.
Reversion: I had an old F-100 with a 390 in it that lost a valve seat in No. 2 cylinder. I found bits of the seat the No. 3 cylinder when I removed the head.
Whats the best way to check that the PCV valve is functioning properly? If the vent tube wasn't seated all the way could that cause a problem?
06-09-2013, 07:34 PM
#10
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Re: Intake Runners coated with oil (PICTURE)
Yeah, it could. But first things first- even if the tube was just swingin' in the breeze, no oil should come out of it. The PCV is supposed to be sucking the oil vaports out the other side of the engine, the vent tube is the CLEAN AIR SUPPLY feeding air back INTO the motor on the other side.
Now, if the PCV system isn't working properly, those vapors will go the OTHER direction- up through the tube into the TB. Oil all over things, as you can imagine.
Your PCV valve (or hose) could be clogged up. I'd replace the valve on general principle (they're cheap). While you have it off, plug it with your finger and have someone fire the motor. You should instantly feel STRONG vacuum on the end of that hose trying to suck your finger in. If not, you have a problem with the hose (clogged, badly split somewhere, perhaps) and that should be addressed before installing the new PCV valve.
Now, if the PCV system isn't working properly, those vapors will go the OTHER direction- up through the tube into the TB. Oil all over things, as you can imagine.
Your PCV valve (or hose) could be clogged up. I'd replace the valve on general principle (they're cheap). While you have it off, plug it with your finger and have someone fire the motor. You should instantly feel STRONG vacuum on the end of that hose trying to suck your finger in. If not, you have a problem with the hose (clogged, badly split somewhere, perhaps) and that should be addressed before installing the new PCV valve.
06-09-2013, 07:54 PM
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Car: 1989 Iroc-Z 350
Re: Intake Runners coated with oil (PICTURE)
Yeah, it could. But first things first- even if the tube was just swingin' in the breeze, no oil should come out of it. The PCV is supposed to be sucking the oil vaports out the other side of the engine, the vent tube is the CLEAN AIR SUPPLY feeding air back INTO the motor on the other side.
Now, if the PCV system isn't working properly, those vapors will go the OTHER direction- up through the tube into the TB. Oil all over things, as you can imagine.
Your PCV valve (or hose) could be clogged up. I'd replace the valve on general principle (they're cheap). While you have it off, plug it with your finger and have someone fire the motor. You should instantly feel STRONG vacuum on the end of that hose trying to suck your finger in. If not, you have a problem with the hose (clogged, badly split somewhere, perhaps) and that should be addressed before installing the new PCV valve.
Now, if the PCV system isn't working properly, those vapors will go the OTHER direction- up through the tube into the TB. Oil all over things, as you can imagine.
Your PCV valve (or hose) could be clogged up. I'd replace the valve on general principle (they're cheap). While you have it off, plug it with your finger and have someone fire the motor. You should instantly feel STRONG vacuum on the end of that hose trying to suck your finger in. If not, you have a problem with the hose (clogged, badly split somewhere, perhaps) and that should be addressed before installing the new PCV valve.
06-09-2013, 09:45 PM
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Re: Intake Runners coated with oil (PICTURE)
It clicked and sucked the **** out of my finger. What else can I try?
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