PCV routing check

[Coal creek Chris]

Wanted to get some advice/verification on my PCV routing/hoses for an 89 454 TBI 3500. The odd part is I have two passenger side valve covers on the engine (past owner did this), so I have two valve covers with only a single PCV grommet in each.

Presently I have the PCV valve on the passenger side valve cover with the hose going to the PCV port on the TBI unit. The driver side valve cover grommet is connected to the metal fitting on the bottom of the air cleaner housing that enters on the inboard side of the air filter. Is this correct? Seems like a simple thing but wanted to see if I might have something hooked up wrong. Should I instead simply install a breather element on the driver side and not connect it to the air cleaner housing? Thanks.

 

[AuroraGirl]

Cross flow is the idea, are they opposite sides, opposite ends? I believe stock air cleaner pointing toward passenger would have a hose to the rear of the cover on passenger and a driver side on the forward section to have a PCv. Or opposite, prob easier to stick in the breather(air cleaner would be moved more?)


What you don’t want to do is two PCv across eachother. That would really do .. I’m not sure. Not good probably

 

[Coal creek Chris]

Cross flow is the idea, are they opposite sides, opposite ends? I believe stock air cleaner pointing toward passenger would have a hose to the rear of the cover on passenger and a driver side on the forward section to have a PCv. Or opposite, prob easier to stick in the breather(air cleaner would be moved more?)


What you don’t want to do is two PCv across eachother. That would really do .. I’m not sure. Not good probably

They are on opposite sides of engine and only one PCV valve. Passenger side cover has the PCV valve connected to the TBI per the emissions sticker routing. Driver side is more of a guess. Driver side is currently an open/free flow hose between the valve cover grommet and the small metal curved fitting on the bottom side of the air cleaner housing.

 

[Octane]

If the driver side hose is hooked to breather and it needs to terminate on outside of filter so as to not get dirty stuff past the filter.There should be a crankcase breather filter attached inside breather or just a breather filter plugged into valve cover

 

[AuroraGirl]

Okay that sounds great, but

They are on opposite sides of engine and only one PCV valve. Passenger side cover has the PCV valve connected to the TBI per the emissions sticker routing. Driver side is more of a guess. Driver side is currently an open/free flow hose between the valve cover grommet and the small metal curved fitting on the bottom side of the air cleaner housing.

Opposite sides, awesome. Opposite ends….? One toward back, other toward front. Doesn’t matter which just need to be opposite. Then the breather thing is true. Is your tho air cleaner two studs or like a carb one? With the little metal fork on the opening that you shove a filter on

 

[Coal creek Chris]

If the driver side hose is hooked to breather and it needs to terminate on outside of filter so as to not get dirty stuff past the filter.There should be a crankcase breather filter attached inside breather or just a breather filter plugged into valve cover

Thanks Octane. As it is now, there is an open connection between the Driver side valve cover and the inboard side of the air filter plus there is no breather filter element on this hose connection. The connection is on the underside of the air filter housing where that small 90-degree bent metal tube comes out of the air filter housing. The Driver side does not connect to the side of the air filter housing, which I have seen on other vehicles. So I would think that the Driver side could be letting dirty stuff enter the TBI without going through the air filter. So seems like I should fix that routing and make it either outside the air filter or just have an open to the air breather directly on the valve cover?

 

[AuroraGirl]

Thanks Octane. As it is now, there is an open connection between the Driver side valve cover and the inboard side of the air filter plus there is no breather filter element on this hose connection. The connection is on the underside of the air filter housing where that small 90-degree bent metal tube comes out of the air filter housing. The Driver side does not connect to the side of the air filter housing, which I have seen on other vehicles. So I would think that the Driver side could be letting dirty stuff enter the TBI without going through the air filter. So seems like I should fix that routing and make it either outside the air filter or just have an open to the air breather directly on the valve cover?

Yes that hole would likely allow dirt to be thrown into tbi if it’s in the center of filter area. If it’s outside filter, it will slightly affect your air flow calibrations and get the filter dirtier but it wouldn’t kill anyone.
The valve cover should not be just open to elements it should have a pcv breather if not connected to a clean air source. and assuming one side is opposite end, last to check is the rattle on valve and cleanliness and the grommets. Weak grommets don’t seal and cause vac leak and don’t do job well. Crankcase pressure isn’t good but the other great thing it’s doing is drying out the crankcase keeping it good

 

[Coal creek Chris]

Okay that sounds great, but



Opposite sides, awesome. Opposite ends….? One toward back, other toward front. Doesn’t matter which just need to be opposite. Then the breather thing is true. Is your tho air cleaner two studs or like a carb one? With the little metal fork on the opening that you shove a filter on

Yes, the passenger side with the PCV valve is to the rear and the driver side is toward the front. I use the driver side as my oil fill cap since my covers are both passenger side covers. Air cleaner is round with a single stud for the cover, looks like the carb one. I've seen some TBI trucks have covers with two studs to attach the cover. Not sure what you mean by the little metal fork to shove a filter on.

 

[Octane]

Thanks Octane. As it is now, there is an open connection between the Driver side valve cover and the inboard side of the air filter plus there is no breather filter element on this hose connection. The connection is on the underside of the air filter housing where that small 90-degree bent metal tube comes out of the air filter housing. The Driver side does not connect to the side of the air filter housing, which I have seen on other vehicles. So I would think that the Driver side could be letting dirty stuff enter the TBI without going through the air filter. So seems like I should fix that routing and make it either outside the air filter or just have an open to the air breather directly on the valve cover?

I saw those little elbows there inside the breather housing. It needs a filter element right there if it terminates between the breather housing and the filter, or if you can get a plug-in type breather filter to snap into the grommet on your valve cover that would work

 

[Coal creek Chris]

Yes that hole would likely allow dirt to be thrown into tbi if it’s in the center of filter area. If it’s outside filter, it will slightly affect your air flow calibrations and get the filter dirtier but it wouldn’t kill anyone.
The valve cover should not be just open to elements it should have a pcv breather if not connected to a clean air source. and assuming one side is opposite end, last to check is the rattle on valve and cleanliness and the grommets. Weak grommets don’t seal and cause vac leak and don’t do job well. Crankcase pressure isn’t good but the other great thing it’s doing is drying out the crankcase keeping it good

Yeah, I meant one of those PCV breathers that just attach directly to the valve cover rather than routing a hose to the air filter area. I live in a place where I need to keep things stock for emissions reasons, so not sure if the plug in breather filters would pass.

 

[AuroraGirl]

Yeah, I meant one of those PCV breathers that just attach directly to the valve cover rather than routing a hose to the air filter area. I live in a place where I need to keep things stock for emissions reasons, so not sure if the plug in breather filters would pass.

It should it’s just a different source for filtered air that was incorporated into the cleaner. I only could see ab anti backfire thingy for Cali or whatever being alart. Spark arrest or maybe

 

[pduffyd]

Coal Creek Chris.

Have a look at this thread it may help a bit too.

"Under Hood Vacuum Diagram and Tuning Stickers"

 

[Scott91370]

https://www.gmsquarebody.com/threads/under-hood-vacuum-diagram-and-tuning-stickers.3520/

 

[Raider L]

@Coal creek Chris,

Get one of these so you won't be sucking oil in with the vapors from the crankcase. It's a "Air/Oil Separator". You can get it and other styles everywhere.

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I replaced these 1/2" hose fittings with AN 6 fittings that were more compatible with my carb.

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Internals. The bar on the left is a piece of 1" x 1/8" alum. flat bar I made for a bracket to mount it to the inner fender. You do you.

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As you can see, PCV valve to the "in" side of the separator, then a hose on the "outlet" side to the carb base. No more oil in the air from the engine.

 

[Raider L]

I can't believe you guys are actually talking about those old timey fiber filters?! Coming from the PCV valve, through the short curved hose, attaches to one of those antique fibrous filters inside the lower air cleaner housing with the metal clip thing that holds it up against the housing side!!

Come on guys! I can see keeping you all's trucks stock, but c'mon man! Gee ****. I was using those things way the heck back when I had my '64 Dodge dart in 1970! Take that thing and throw it in the trash! All that does is turn your air cleaner into a "oil bath type air cleaner". Me and maybe a couple of other guys on this site remember those things. I do. I had a vehicle that had a oil bath air cleaner on it, a '54 International Harvester long bed pickup! The only reason why I even knew what it was when I got that truck, was because I used to help my Uncle clean and change his out in his '53 Plymouth he had when he was in high school when I was a little kid, in the '50's! That's what you've got with that PVC filter!

I remember whenit came time to change the air cleaner there would be oil pooled all along the curved lower portion of the lower housing that had dripped out from that useless filter. Now you do have a oil bath filter because I look at the air cleaner and it would be soaked all along one side of the filter material. Thinking about how much oil must have entered the carb I'm bordering on having a diesel engine than a gasoline internal combustion engine!

So, get with the times guys, and think no wonder why you can't find those PCV filters is because NO ONE uses them anymore because they are relics of a bygone era! Get one of what I showed you, it'll even work on a TBI injection system. And another thing, you want a antique filter on a modern fuel injection system? C'MON!