Pulling vacaum through oil filler tube.

Mopar1 · 09-15-2002, 10:15 PM

Is this normal. I have a breather in place of the cap. The tube going to the TB is plugged on both ends. As I put my hand over oil filler tube, you can feel it build vacaum. PCV is hooked up and new.

93GTDIN · 09-16-2002, 12:50 AM

That's the idea behind the line that is connected to the throttle body. Replacing it with a breather is a fine alternative but some argue that it's never good to bring unmetered air into the engine. I'm not too sure if I put stock in that or not but thats what they say.

Mopar1 · 09-16-2002, 09:45 AM

Their is no unmetered air going to the TB. The nipples on the oilfiller cap and TB are plugged. The situation is the vacaum in the crank case. Is that a normal thing.

heheheh I sais nipples...lol

93GTDIN · 09-17-2002, 12:06 AM

i know no unmetered air goes into the throttle body, but it does go into the crankcase. Your car is fine.

SlowGT · 09-17-2002, 09:34 PM

I had the same issue after my last set of upgrades. Now my dipstick resides in the hood and my dipstick tube has a breather on it. Scared me at first. Thought it was compression bleeding down, cause the only time you could here it was right after you shut the engine off.

PKRWUD · 09-18-2002, 05:23 AM

The air that goes into the crankcase via the oil fill tube ends up going through the PCV, and into the intake. That is why the line goes from the tube to the TB. That way, any air that goes in has already passed by the MAF, and has been accounted for. By installing a filter on the tube, and disconnecting the line to the TB, you essentially have created a vacuum leak.

Take care,
~Chris

Mopar1 · 09-18-2002, 08:27 AM

Its running good. should I put it back? Also, why is the pcv in the intake and not in the rocker arm cover? Could I relocate it there and what if any effect would that have?

PKRWUD · 09-18-2002, 08:48 AM

If you like it, leave it. I was just letting you know that it basically creates a vacuum leak.

For a PCV system to work properly, there needs to be a place for fresh, filtered air to enter the crankcase, and a place for it to leave (PCV valve). These two locations need to be as far apart from each other as possible. Most engines have the air enter in one valve cover, and exit out the other valve cover, but the design of the intake manifold on the EFI 5.0 engines makes this difficult, so they moved the PCV to the rear of the intake manifold.

Take care,
~Chris

Mopar1 · 09-18-2002, 09:36 AM

Hmm, Ill play around with it some more. There is a thread on corral.net about oil getting sucked up the pcv to the intake. When I took my upper off couple of days ago, there was oil on the gasket. From that thread it seems to be a common occurence. With the vehicles that I have owned I've never had this prob.

PKRWUD · 09-18-2002, 09:55 AM

There is a filter underneath the PCV valve in the intake, and if it is not replaced every so often, it actually encourages oil to "hang out" in it, which makes it easy for the oil to get sucked up into the PCV valve, and into the intake. In a similar light, aftermarket intakes often require a baffle be installed there, but it rarely is, which also encourages oil to be sucked into the PCV.

Take care,
~Chris

P.S. While designing your PCV system, remember that unless the air that enters the crankcase first goes through the MAF, it will be unmetered air, which is the same thing as a vacuum leak. Just incase this last part isn't fully understood, allow me to elaborate. Air enters the crankcase through the oil fill tube. It circulates through the crankcase, picking up air contaminated with blow-by gasses, and exits the crankcase at the PCV valve. From there, it goes to a vacuum port on the intake, and ultimately into the combustion chambers. Since it is air that ends up in the combustion chambers, it needs to be accounted for, thus, metered, by the MAF. That is why the factory source for this air is at the TB. That way, the air has already been filtered and metered before it enters the crankcase, and ultimately, the combustion chambers.

Stang_ROTY · 09-18-2002, 03:31 PM

Chris is right. I didn't have the filter or "baffle plate" (as Edelbrock calls it) installed last year and I used to get tons of white smoke during startup and oil in my upper manifold and on the plugs. I didn't realize that the stock piece was a filter because the Edelbrock baffle plate is actually a metal plate. This year when I had the engine out we put the baffle plate in and I haven't had the problem since :-)

Quote:

Originally posted by PKRWUD
There is a filter underneath the PCV valve in the intake, and if it is not replaced every so often, it actually encourages oil to "hang out" in it, which makes it easy for the oil to get sucked up into the PCV valve, and into the intake. In a similar light, aftermarket intakes often require a baffle be installed there, but it rarely is, which also encourages oil to be sucked into the PCV.

Take care,
~Chris

P.S. While designing your PCV system, remember that unless the air that enters the crankcase first goes through the MAF, it will be unmetered air, which is the same thing as a vacuum leak. Just incase this last part isn't fully understood, allow me to elaborate. Air enters the crankcase through the oil fill tube. It circulates through the crankcase, picking up air contaminated with blow-by gasses, and exits the crankcase at the PCV valve. From there, it goes to a vacuum port on the intake, and ultimately into the combustion chambers. Since it is air that ends up in the combustion chambers, it needs to be accounted for, thus, metered, by the MAF. That is why the factory source for this air is at the TB. That way, the air has already been filtered and metered before it enters the crankcase, and ultimately, the combustion chambers.

Mopar1 · 09-18-2002, 04:46 PM

Excellent point as always P. The typhoon intake does have a baffle and filter, but oil still gets into the intake.

When I was racing the duster ,I had a valley baffle to prevent oil from splashing up on the bottom of the intake. I wonder if this will /would be benifical. Or is this outdated thinking..lol

PKRWUD · 09-18-2002, 05:10 PM

The higher the volume of air that is allowed to flow through the PCV, the better the odds of it bringing oil with it. The two items that control this flow rate are the PCV valve and the diameter of the tube that connects the TB to the oil fill tube. If you're sure the PCV valve is the correct one, and is in good working order, try going back to the way it was with the tube going to the TB from the oil fill tube, and see if that doesn't help. Having an open element filter on top of the oil fill tube allows a much greater volume of air to be sucked in to the engine and out through the PCV. I'm not making any guarantees, but this is how the system works.

Take care,
~Chris

Mopar1 · 09-18-2002, 05:29 PM

Your opinions on the valley baffle?

Its back to orginal config. It still takes oil. What about reducing the tube from TB to the oil filler tube.

09-18-2002, 05:45 PM

PKRWUD_
So are you saying that all fuel injected 5.0s, whether mildy or heavily modified, should have the tube from the TB to the oil filler tube connected? My thoughts were that when doing a speed run or when the engine is at full throttle, excess oil may travel from the oil filler tube (my baffle is out of the passenger side valve cover because of my 1.72 rockers) to the throttle body and get sucked into the upper intake & into the motor. Oil in my upper intake manifold doesn't sound like a good idea? So should I have that tube connected then? Thanks in advance.

PKRWUD · 09-18-2002, 06:45 PM

Quote:

Originally posted by Mopar1
Your opinions on the valley baffle?

Its back to orginal config. It still takes oil. What about reducing the tube from TB to the oil filler tube.

Valley baffle? Not sure what you mean. Are you talking about a valley shield, like the Olds/Pontiac manifold gaskets?

If you have it back to orig., and it's still sucking oil up past the PCV, you have a problem. Do you have a high volume oil pump? You may be best off just plugging the PCV all together, and getting a valve cover with two elevated breather tubes, and putting open element filters in both tubes.

PKRWUD · 09-18-2002, 06:56 PM

Quote:

Originally posted by Simi Stang
PKRWUD_
So are you saying that all fuel injected 5.0s, whether mildy or heavily modified, should have the tube from the TB to the oil filler tube connected?

No, I'm not. As I just suggested to Mopar 1, sometimes blocking off the PCV all together, and having dual (at least) breather tubes off the valve cover is the best bet. The tube from the TB to the oil fill tube should be connected if you are using the PCV system. Your case, however, is one where trial and error is going to be the best bet. Not having the baffle will increase the odds of your fears coming true, because at WOT, there is little to no vacuum available for the PCV, but quite a bit at the TB, so the tube from the TB to the oil fill tube could easily suck in any oil that came up the oil fill tube. Try hooking it back up, and see what happens. If it gets oil in the tube going to the TB, then remove it, and consider the same advice I gave to Mopar 1; getting a valve cover with dual breather stacks, and blocking off the PCv completely.

Take care,
~Chris

09-18-2002, 07:17 PM

Thanks PKRWUD I'll experiment a little with that.

PKRWUD · 09-18-2002, 07:35 PM

If you don't mind, keep me posted. I'm curious to know what works best for you.

Take care,
~Chris

09-15-2002, 10:15 PM	#1
Mopar1 Registered Member Join Date: Mar 2002 Location: Lakewood, Wa Posts: 161	Pulling vacaum through oil filler tube. Is this normal. I have a breather in place of the cap. The tube going to the TB is plugged on both ends. As I put my hand over oil filler tube, you can feel it build vacaum. PCV is hooked up and new. __________________ '77 Aspen R/T: 318 w/273 heads, 4spd, Hurst Shifter, 600 holley, edelbrock intake, 8 3/4 axle, 3.23 sure-grip, dual 3" exhaust, MP cam 276 / 276 duration 490 / 490 mech solid lifter, Super Stock Springs (15.65@88 3900lbs) '91 Mustang LX: .030 Bored, Typhoon Intake, 4.10's, Lentech VB, BBK 70mm TB, FMS A/C elim bracket, 19lbs inject, off road H-pipe, 75mm pro-m MAF, FRP unequal shorty, stormin normin hood. 3420 Lbs w/ 220 (me) and 13 gal gas. '02 SS Camaro

09-16-2002, 12:50 AM	#2
93GTDIN Registered Member Join Date: Jan 2001 Location: Live music capital of the world, TX Posts: 324	That's the idea behind the line that is connected to the throttle body. Replacing it with a breather is a fine alternative but some argue that it's never good to bring unmetered air into the engine. I'm not too sure if I put stock in that or not but thats what they say. __________________ 96 Cobra - a bit too stock. 14.0 @ 101

09-16-2002, 09:45 AM	#3
Mopar1 Registered Member Join Date: Mar 2002 Location: Lakewood, Wa Posts: 161	Their is no unmetered air going to the TB. The nipples on the oilfiller cap and TB are plugged. The situation is the vacaum in the crank case. Is that a normal thing. heheheh I sais nipples...lol __________________ '77 Aspen R/T: 318 w/273 heads, 4spd, Hurst Shifter, 600 holley, edelbrock intake, 8 3/4 axle, 3.23 sure-grip, dual 3" exhaust, MP cam 276 / 276 duration 490 / 490 mech solid lifter, Super Stock Springs (15.65@88 3900lbs) '91 Mustang LX: .030 Bored, Typhoon Intake, 4.10's, Lentech VB, BBK 70mm TB, FMS A/C elim bracket, 19lbs inject, off road H-pipe, 75mm pro-m MAF, FRP unequal shorty, stormin normin hood. 3420 Lbs w/ 220 (me) and 13 gal gas. '02 SS Camaro

09-17-2002, 12:06 AM	#4
93GTDIN Registered Member Join Date: Jan 2001 Location: Live music capital of the world, TX Posts: 324	i know no unmetered air goes into the throttle body, but it does go into the crankcase. Your car is fine. __________________ 96 Cobra - a bit too stock. 14.0 @ 101

09-17-2002, 09:34 PM	#5
SlowGT Registered Member Join Date: Jun 1999 Location: Columbia Co, PA Posts: 303	I had the same issue after my last set of upgrades. Now my dipstick resides in the hood and my dipstick tube has a breather on it. Scared me at first. Thought it was compression bleeding down, cause the only time you could here it was right after you shut the engine off. __________________ Old Slow GT New Slow GT--> under construction Latest Addition: 95 Cobra R, #73, bone stock, ~6100 miles.

09-18-2002, 05:23 AM	#6
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	The air that goes into the crankcase via the oil fill tube ends up going through the PCV, and into the intake. That is why the line goes from the tube to the TB. That way, any air that goes in has already passed by the MAF, and has been accounted for. By installing a filter on the tube, and disconnecting the line to the TB, you essentially have created a vacuum leak. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

09-18-2002, 08:27 AM	#7
Mopar1 Registered Member Join Date: Mar 2002 Location: Lakewood, Wa Posts: 161	Its running good. should I put it back? Also, why is the pcv in the intake and not in the rocker arm cover? Could I relocate it there and what if any effect would that have? __________________ '77 Aspen R/T: 318 w/273 heads, 4spd, Hurst Shifter, 600 holley, edelbrock intake, 8 3/4 axle, 3.23 sure-grip, dual 3" exhaust, MP cam 276 / 276 duration 490 / 490 mech solid lifter, Super Stock Springs (15.65@88 3900lbs) '91 Mustang LX: .030 Bored, Typhoon Intake, 4.10's, Lentech VB, BBK 70mm TB, FMS A/C elim bracket, 19lbs inject, off road H-pipe, 75mm pro-m MAF, FRP unequal shorty, stormin normin hood. 3420 Lbs w/ 220 (me) and 13 gal gas. '02 SS Camaro

09-18-2002, 08:48 AM	#8
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	If you like it, leave it. I was just letting you know that it basically creates a vacuum leak. For a PCV system to work properly, there needs to be a place for fresh, filtered air to enter the crankcase, and a place for it to leave (PCV valve). These two locations need to be as far apart from each other as possible. Most engines have the air enter in one valve cover, and exit out the other valve cover, but the design of the intake manifold on the EFI 5.0 engines makes this difficult, so they moved the PCV to the rear of the intake manifold. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

09-18-2002, 09:36 AM	#9
Mopar1 Registered Member Join Date: Mar 2002 Location: Lakewood, Wa Posts: 161	Hmm, Ill play around with it some more. There is a thread on corral.net about oil getting sucked up the pcv to the intake. When I took my upper off couple of days ago, there was oil on the gasket. From that thread it seems to be a common occurence. With the vehicles that I have owned I've never had this prob. __________________ '77 Aspen R/T: 318 w/273 heads, 4spd, Hurst Shifter, 600 holley, edelbrock intake, 8 3/4 axle, 3.23 sure-grip, dual 3" exhaust, MP cam 276 / 276 duration 490 / 490 mech solid lifter, Super Stock Springs (15.65@88 3900lbs) '91 Mustang LX: .030 Bored, Typhoon Intake, 4.10's, Lentech VB, BBK 70mm TB, FMS A/C elim bracket, 19lbs inject, off road H-pipe, 75mm pro-m MAF, FRP unequal shorty, stormin normin hood. 3420 Lbs w/ 220 (me) and 13 gal gas. '02 SS Camaro

09-18-2002, 09:55 AM	#10
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	There is a filter underneath the PCV valve in the intake, and if it is not replaced every so often, it actually encourages oil to "hang out" in it, which makes it easy for the oil to get sucked up into the PCV valve, and into the intake. In a similar light, aftermarket intakes often require a baffle be installed there, but it rarely is, which also encourages oil to be sucked into the PCV. Take care, ~Chris P.S. While designing your PCV system, remember that unless the air that enters the crankcase first goes through the MAF, it will be unmetered air, which is the same thing as a vacuum leak. Just incase this last part isn't fully understood, allow me to elaborate. Air enters the crankcase through the oil fill tube. It circulates through the crankcase, picking up air contaminated with blow-by gasses, and exits the crankcase at the PCV valve. From there, it goes to a vacuum port on the intake, and ultimately into the combustion chambers. Since it is air that ends up in the combustion chambers, it needs to be accounted for, thus, metered, by the MAF. That is why the factory source for this air is at the TB. That way, the air has already been filtered and metered before it enters the crankcase, and ultimately, the combustion chambers. __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

09-18-2002, 04:46 PM	#12
Mopar1 Registered Member Join Date: Mar 2002 Location: Lakewood, Wa Posts: 161	Excellent point as always P. The typhoon intake does have a baffle and filter, but oil still gets into the intake. When I was racing the duster ,I had a valley baffle to prevent oil from splashing up on the bottom of the intake. I wonder if this will /would be benifical. Or is this outdated thinking..lol __________________ '77 Aspen R/T: 318 w/273 heads, 4spd, Hurst Shifter, 600 holley, edelbrock intake, 8 3/4 axle, 3.23 sure-grip, dual 3" exhaust, MP cam 276 / 276 duration 490 / 490 mech solid lifter, Super Stock Springs (15.65@88 3900lbs) '91 Mustang LX: .030 Bored, Typhoon Intake, 4.10's, Lentech VB, BBK 70mm TB, FMS A/C elim bracket, 19lbs inject, off road H-pipe, 75mm pro-m MAF, FRP unequal shorty, stormin normin hood. 3420 Lbs w/ 220 (me) and 13 gal gas. '02 SS Camaro Last edited by Mopar1; 09-18-2002 at 05:07 PM..

09-18-2002, 05:10 PM	#13
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	The higher the volume of air that is allowed to flow through the PCV, the better the odds of it bringing oil with it. The two items that control this flow rate are the PCV valve and the diameter of the tube that connects the TB to the oil fill tube. If you're sure the PCV valve is the correct one, and is in good working order, try going back to the way it was with the tube going to the TB from the oil fill tube, and see if that doesn't help. Having an open element filter on top of the oil fill tube allows a much greater volume of air to be sucked in to the engine and out through the PCV. I'm not making any guarantees, but this is how the system works. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

09-18-2002, 05:29 PM	#14
Mopar1 Registered Member Join Date: Mar 2002 Location: Lakewood, Wa Posts: 161	Your opinions on the valley baffle? Its back to orginal config. It still takes oil. What about reducing the tube from TB to the oil filler tube. __________________ '77 Aspen R/T: 318 w/273 heads, 4spd, Hurst Shifter, 600 holley, edelbrock intake, 8 3/4 axle, 3.23 sure-grip, dual 3" exhaust, MP cam 276 / 276 duration 490 / 490 mech solid lifter, Super Stock Springs (15.65@88 3900lbs) '91 Mustang LX: .030 Bored, Typhoon Intake, 4.10's, Lentech VB, BBK 70mm TB, FMS A/C elim bracket, 19lbs inject, off road H-pipe, 75mm pro-m MAF, FRP unequal shorty, stormin normin hood. 3420 Lbs w/ 220 (me) and 13 gal gas. '02 SS Camaro

09-18-2002, 05:45 PM	#15
Simi Stang Guest Posts: n/a	PKRWUD PKRWUD_ So are you saying that all fuel injected 5.0s, whether mildy or heavily modified, should have the tube from the TB to the oil filler tube connected? My thoughts were that when doing a speed run or when the engine is at full throttle, excess oil may travel from the oil filler tube (my baffle is out of the passenger side valve cover because of my 1.72 rockers) to the throttle body and get sucked into the upper intake & into the motor. Oil in my upper intake manifold doesn't sound like a good idea? So should I have that tube connected then? Thanks in advance.

09-18-2002, 07:17 PM	#18
Simi Stang Guest Posts: n/a	Pulling vacuum through oil filler tube Thanks PKRWUD I'll experiment a little with that.

09-18-2002, 07:35 PM	#19
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	If you don't mind, keep me posted. I'm curious to know what works best for you. Take care, ~Chris __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Tranny filler tube?	mystang_71	Classic Mustangs	2	07-10-2003 03:25 PM
how to replace gas tank filler tube grommet?	chaos	Windsor Power	5	08-16-2002 09:37 AM
broken dipstick tube	matt cook	Windsor Power	11	04-27-2002 03:39 PM
CAI with C&L inlet tube?	chris91LX	Windsor Power	11	04-16-2002 08:20 PM
What to do about the air tube with my BBK LT h-pipe	Jason Van Holland	Windsor Power	4	01-17-2001 04:35 PM