Oil Blow By
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Teching In
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From: South Florida
Re: Oil Blow By This may be unique to my application. Since I'm road racing not drag racing, I'm under boost for longer periods of time.
During a 30 minute session I'm probably under boost 60% of the time. I guess the constant pressure build up is too much and the oil starts blowing out.
I hope someone has some ideas..
During a 30 minute session I'm probably under boost 60% of the time. I guess the constant pressure build up is too much and the oil starts blowing out.
I hope someone has some ideas..
Thread Starter
Teching In
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From: South Florida
Oil Blow By Just spent yesterday cleaning out the hoses/pipes/intercoolers on my ATI. I spent the day Saturday lapping at Miami/Homestead speedway. When I got home I noticed some oil around the inlet hat.
Further inspection showed that there was considerable oil in the inlet hat and had actually made it all the way to the intercoolers. I talked to Jason at GWP and we agree that it is oil blow by from the crankcase pressure.
I've already installed a check valve on the PCV line. I've had that since the beginning. I double checked yesterday and it does appear that I've got the flow direction right.
Any suggestions as to how I can deal with this issue. Jason recommended an EVAC setup but I'm cheap and would like to try something else first.
Thanks.
__________________
Gary
'99 Trans Am
510.8 hp/477.7 torque
-----------------
www.gdjenkins.com/mods.html
Further inspection showed that there was considerable oil in the inlet hat and had actually made it all the way to the intercoolers. I talked to Jason at GWP and we agree that it is oil blow by from the crankcase pressure.
I've already installed a check valve on the PCV line. I've had that since the beginning. I double checked yesterday and it does appear that I've got the flow direction right.
Any suggestions as to how I can deal with this issue. Jason recommended an EVAC setup but I'm cheap and would like to try something else first.
Thanks.
__________________
Gary
'99 Trans Am
510.8 hp/477.7 torque
-----------------
www.gdjenkins.com/mods.html
On The Tree
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Re: Oil Blow By My brother has a ATI blown 200 WS6 with the same problem. He does not have a check valve installed on his.
He did call ATI, and they know of the problem, but do not have a fix for it.
What is a evac pump?
John
He did call ATI, and they know of the problem, but do not have a fix for it.
What is a evac pump?
John
On The Tree
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From: Warner Robins, GA, CSA
Re: Oil Blow By Most, if not all of the Gen II Lightnings have this problem too. We struggle with solutions too and so far, a 'catch-can' may be the answer.
I have blocked/disabled the PCV valve and then the oil get's blown'pressurized out the crankcase breathers and 'burns as it drips onto the exhaust manifolds. I ran a total of 3 breathers for a while. Right now, I freed up the PCV valve and have just an oil breather cap. May try the catch-can soon?
Dan
I have blocked/disabled the PCV valve and then the oil get's blown'pressurized out the crankcase breathers and 'burns as it drips onto the exhaust manifolds. I ran a total of 3 breathers for a while. Right now, I freed up the PCV valve and have just an oil breather cap. May try the catch-can soon?
Dan
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From: Centrifugal City
Re: Oil Blow By The more I think about this problem and why the PCV Check Valve solves it..
Wouldn't it be not the vacuum created during boost, but the positive pressure created when the Throttle Body blade closes after a WOT run. This positive pressure forces the weak stock PCV valve open. This pressure blows into the valve cover and exits out the fresh air valvecover nub, spewing out the pressure and oil with it.
The PCV check valve prevents this positive pressure 'blow off' from entering the PCV system. A good blow off valve should help too, eh?
Wouldn't it be not the vacuum created during boost, but the positive pressure created when the Throttle Body blade closes after a WOT run. This positive pressure forces the weak stock PCV valve open. This pressure blows into the valve cover and exits out the fresh air valvecover nub, spewing out the pressure and oil with it.
The PCV check valve prevents this positive pressure 'blow off' from entering the PCV system. A good blow off valve should help too, eh?
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From: Raleigh, NC
Re: Oil Blow By I wonder why I've never experienced this problem. Not complaining, mind you... just odd.
I check mine again just a week or so ago, because of the posts about it, and that hose going to the inlet hat is clean and dry.
I check mine again just a week or so ago, because of the posts about it, and that hose going to the inlet hat is clean and dry.
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From: Raleigh, NC
Re: Oil Blow By I bought it, but never put it in. (It was relatively cheap, so I figured I'd have it, just in case. It's in a plastic zip-lock bag in my armrest compartment.
Jason seemed dubious about the need for it. I guess we both felt if I didn't have a problem, why dic with it. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
Jason seemed dubious about the need for it. I guess we both felt if I didn't have a problem, why dic with it. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
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From: Derby, KS
Re: Oil Blow By </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TaxMan:
<strong>I was told today that one of the Cadillac engines has an electrical evac pump on it. Anyone know anything about that?
Gary.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I posed that question to my brother, who knows more about Cadillac engines then anyone I know, (pasted from his email):
"The big inch cads (68-76) never had that that I know of. I mean, they had
some weird stuff, like electric air compressors to drive air shocks,
hydroboost brake boosters that are driven by the power steering, and even
multipoint fuel injection ('76 only), and climate control computers, but I
never heard of a vacuum pump on the ones I mess with.
My guess is that if it is for blowby, it would have been for the disastrous
aluminum 4.1 front drive V-8 in the '80's. From what I have seen in my
Electrical component locator (1988 Mitchell), there is an electric vacuum
pump located inside the left front fender, at the front of the vehicle on
1988 Deville's and or Fleetwoods, it is probably located in other years of
those models, also. However, the Allante/Cimmaron/Fleetwood Broughams/El
Dorados/Sevilles do not show it.
There is no computer trouble code for the vacuum pump in the Deville and
Fleetwood diagnostic section, so if you want to find in-depth information,
you may need to do some digging."
Tim
<strong>I was told today that one of the Cadillac engines has an electrical evac pump on it. Anyone know anything about that?
Gary.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I posed that question to my brother, who knows more about Cadillac engines then anyone I know, (pasted from his email):
"The big inch cads (68-76) never had that that I know of. I mean, they had
some weird stuff, like electric air compressors to drive air shocks,
hydroboost brake boosters that are driven by the power steering, and even
multipoint fuel injection ('76 only), and climate control computers, but I
never heard of a vacuum pump on the ones I mess with.
My guess is that if it is for blowby, it would have been for the disastrous
aluminum 4.1 front drive V-8 in the '80's. From what I have seen in my
Electrical component locator (1988 Mitchell), there is an electric vacuum
pump located inside the left front fender, at the front of the vehicle on
1988 Deville's and or Fleetwoods, it is probably located in other years of
those models, also. However, the Allante/Cimmaron/Fleetwood Broughams/El
Dorados/Sevilles do not show it.
There is no computer trouble code for the vacuum pump in the Deville and
Fleetwood diagnostic section, so if you want to find in-depth information,
you may need to do some digging."
Tim
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From: Centrifugal City
Re: Oil Blow By </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TaxMan:
<strong>I have the check valve installed in the PCV line. So at least in my instance the blow by is not from that source.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not to be thick, but your arrow on the check valve points towards the Throttle Body, right?
<strong>I have the check valve installed in the PCV line. So at least in my instance the blow by is not from that source.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not to be thick, but your arrow on the check valve points towards the Throttle Body, right?
Thread Starter
Teching In
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From: South Florida
Re: Oil Blow By </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MelloYellow:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TaxMan:
<strong>I have the check valve installed in the PCV line. So at least in my instance the blow by is not from that source.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not to be thick, but your arrow on the check valve points towards the Throttle Body, right?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Actually it was the first thing I checked. I even took it off and blew through the valve just to make sure I had it right. So, yes. It is installed the correct way.
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TaxMan:
<strong>I have the check valve installed in the PCV line. So at least in my instance the blow by is not from that source.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not to be thick, but your arrow on the check valve points towards the Throttle Body, right?</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Actually it was the first thing I checked. I even took it off and blew through the valve just to make sure I had it right. So, yes. It is installed the correct way.
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From: Centrifugal City
Re: Oil Blow By You could install catch can off the fresh air intake nub on the passenger front valve cover and use a breather filter after the catch can. A compressor air filter like I use on my PCV would work as a good catch can.
Or you could try adding another check valve there, but I'm not sure how much suction, if any is created off that nub.. after that a breather filter.
Or you could try adding another check valve there, but I'm not sure how much suction, if any is created off that nub.. after that a breather filter.
Thread Starter
Teching In
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From: South Florida
Re: Oil Blow By Okay, here is where I get confused. Or at least my knowledge stops.
I have thought about adding a catch can with a breather filter. However, I thought the purpose of having the hose run from the valve cover to the inlet hat on the ATI was to 'suck' any pressure buildup in the valve cover out.
If I add a catch can, the 'sucking' won't happen. With my limited knowledge I can't decide if that would be bad for my application.
Any thoughts??
I have thought about adding a catch can with a breather filter. However, I thought the purpose of having the hose run from the valve cover to the inlet hat on the ATI was to 'suck' any pressure buildup in the valve cover out.
If I add a catch can, the 'sucking' won't happen. With my limited knowledge I can't decide if that would be bad for my application.
Any thoughts??
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From: Centrifugal City
Re: Oil Blow By There are 2 nubs on the passenger valvecover. 1 is for sucking out at the rear and also has tubing to the rear driver valvecover. This is where vacuum sucks out pressure and goes thru the PCV system. This is where you'd suck oil into your throttle body.
The passenger side has a 2nd nub at the front of the valvecover. This is used to bring in fresh air while the other air is sucked out. Now if you pressurize the crankcase under boost it builds up pressure and the fresh air nub is the only place it can release pressure and this is where the oil shoots out.
The only issue on the fresh air nub is whether it sucks in MAF metered air or not. The normal ATI system just routes it up to your air filter area and it isn't metered anyhow. So a breather on the FRESH AIR nub is ok and your PCV system remains in place with a check valve. The fresh air nub could have a catch can or maybe another check valve installed in addition to the breather, otherwise you'll just shoot oil out the breather instead of into your air filter and intercoolers.
The passenger side has a 2nd nub at the front of the valvecover. This is used to bring in fresh air while the other air is sucked out. Now if you pressurize the crankcase under boost it builds up pressure and the fresh air nub is the only place it can release pressure and this is where the oil shoots out.
The only issue on the fresh air nub is whether it sucks in MAF metered air or not. The normal ATI system just routes it up to your air filter area and it isn't metered anyhow. So a breather on the FRESH AIR nub is ok and your PCV system remains in place with a check valve. The fresh air nub could have a catch can or maybe another check valve installed in addition to the breather, otherwise you'll just shoot oil out the breather instead of into your air filter and intercoolers.
