New 383 high oil consumption

[Craig Nedrow]

Just replaced the 350 with another 350 in my K20, was using lots of oil, and oil on the intake etc. Had tall valve covers with breathers. Took the tall covers off, installed the stockers and the stock pcv stuff, and now no oil leaks or consumption, about 2000 miles now. Just a thought.

 

[4WDKC]

I just swapped the valve covers on my vette because of oil being sucked into the engine above 3k you could smell the oil burning. |Replaced them with baffled ones and no issues now. We are coming into summer now, i would run 10w30 in it for an oil change and see how it does.

 

[Daveo91Burb]

What are you running for valve covers? My brother in law bought some really nice cast aluminum valve covers for his 455. I guess I should clarify, the machining and casting look top notch, my only issue is where the cast the hole for the breather and PCV valve. It’s directly above one of the pushrods, it basically squirts oil directly into the PCV valve. On the other side of the engine, it will fill the breaker element with oil after a couple minutes run time. The engine didn’t use a drop of oil before the valve cover swap, now it’s a smoky leaky mess. I told him he needs to either put the stock stuff back on, or fabricate some baffles to keep the oil out of places it isn’t wanted.

If your engine has the PVC vacuum source located in The carb plenum, every cylinder could be burning just a little oil. Maybe that’s why all the plugs look clean. Is the PCV valve hose oily?

I just swapped the valve covers on my vette because of oil being sucked into the engine above 3k you could smell the oil burning. |Replaced them with baffled ones and no issues now. We are coming into summer now, i would run 10w30 in it for an oil change and see how it does.

Thanks for the thoughts on valve covers and PCV system. I’ve definitely considered the PCV system as possibly part of the problem, mostly because the lack of smoke, clean plugs, and all cylinders with same compression. Tonight I just replaced the valve for the second time, this time with an AC Delco. There was maybe a little oil in the tube, but not lots. As for valve covers I’m just using stock Vortec covers which I believe are virtually the same as stock TBI. (Stamped steel, painted black, ribs along the length). Dumb question... it doesn’t matter which direction the PCV system runs does it? On the burb I have the vacuum line from the TB going to the front of the PS valve cover with the breather on the back of the DS, but on my Vette — also with Vortec heads — I have it set up the opposite way. Grasping at straws....

And yes, I forgot to mention, the Rotella oil I used was 10w-30.

 

[Matt69olds]

With the engine running, put a piece of paper over the valve cover hole where the breather would go. There should be enough vacuum to hold it in place. If not, you need to find where the leak is. That’s usually pretty easy, just look for the oil leak. It shouldn’t matter which side the valve or breather is on, as long as things are working as they should.

 

[4WDKC]

Thanks for the thoughts on valve covers and PCV system. I’ve definitely considered the PCV system as possibly part of the problem, mostly because the lack of smoke, clean plugs, and all cylinders with same compression. Tonight I just replaced the valve for the second time, this time with an AC Delco. There was maybe a little oil in the tube, but not lots. As for valve covers I’m just using stock Vortec covers which I believe are virtually the same as stock TBI. (Stamped steel, painted black, ribs along the length). Dumb question... it doesn’t matter which direction the PCV system runs does it? On the burb I have the vacuum line from the TB going to the front of the PS valve cover with the breather on the back of the DS, but on my Vette — also with Vortec heads — I have it set up the opposite way. Grasping at straws....

And yes, I forgot to mention, the Rotella oil I used was 10w-30.

The vortec valve covers have a different sized breather tube that connects to the tbi. I had to put my nasty tbi valve covers back on so the tube would seal at the VC. Placement does matter if for nothing else ease of adding oil. The pcv grommet is smaller making you need a smaller funnel and slowing down the process. If you put the PCV at the front of the engine and try to fill via the breather or cap if stock VC it can be a bitch to add oil with the booster or AC box in the way. Also the VC bolts are not truly centered and are offset so you have to put them on a certain way. You cant just take the ps off flip it 180* and reinstall it on the ps.

 

[Daveo91Burb]

The vortec valve covers have a different sized breather tube that connects to the tbi. I had to put my nasty tbi valve covers back on so the tube would seal at the VC. Placement does matter if for nothing else ease of adding oil. The pcv grommet is smaller making you need a smaller funnel and slowing down the process. If you put the PCV at the front of the engine and try to fill via the breather or cap if stock VC it can be a bitch to add oil with the booster or AC box in the way. Also the VC bolts are not truly centered and are offset so you have to put them on a certain way. You cant just take the ps off flip it 180* and reinstall it on the ps.

Yeah, I had to deal with those differences between the two types, but I think they all work now. Oil filler tube is indeed close to the brake booster, but a I have a funnel that fits in there fairly well to fill. As for the breather on the back of the DS valve cover I had to engineer a reduction in the size to get it to mate with the tube on the ring that goes between the air cleaner and TB (Not using that ring now since I built a salad bowl air intake and the PCV intake is incorporated into the back of that). I have a lot of spare parts in that area from my Vette and multiple TBIs that I've accumulated. So....A few differences, but doesn't seem like I can attribute my oil consumption to them.

 

[4WDKC]

Yeah, I had to deal with those differences between the two types, but I think they all work now. Oil filler tube is indeed close to the brake booster, but a I have a funnel that fits in there fairly well to fill. As for the breather on the back of the DS valve cover I had to engineer a reduction in the size to get it to mate with the tube on the ring that goes between the air cleaner and TB (Not using that ring now since I built a salad bowl air intake and the PCV intake is incorporated into the back of that). I have a lot of spare parts in that area from my Vette and multiple TBIs that I've accumulated. So....A few differences, but doesn't seem like I can attribute my oil consumption to them.

pcv in the salad bowl or the breather?

 

[Frankenchevy]

My vortec valve covers have a single hole on passenger side front (where I put my breather) and a hole on ds rear (where I put my pcv) as well as an oil filler hole on driver side front. I didn’t think the pcv vs breather location mattered. The grommets are the same size on a my vortec gm valve covers (3/4)” versus my 327 valve covers which are an inch or maybe 7/8”...

 

[Daveo91Burb]

pcv in the salad bowl or the breather?

breather tube is connected to the salad bowl and goes to rear of DS cover. PCV is in front of PS cover. So it sucks filtered air through the engine.

My vortec valve covers have a single hole on passenger side front (where I put my breather) and a hole on ds rear (where I put my pcv) as well as an oil filler hole on driver side front. I didn’t think the pcv vs breather location mattered. The grommets are the same size on a my vortec gm valve covers (3/4)” versus my 327 valve covers which are an inch or maybe 7/8”...

Yeah, you've got it set up opposite of me, but I agree it shouldn't matter.