PCV setup, oil consumption, upgraded parts, blue smoke, the works...
08-25-2012, 11:08 PM
#1
PCV setup, oil consumption, upgraded parts, blue smoke, the works... Thanks to all who read this.
I have been trying to minimize my oil consumption for some time now and haven't really made any progress. Car uses around 1.5 qts per 1000 miles. I don't drive this car like a grandma so I know I will be using more than most people. From what I have read, I have the pcv routing correct. Read many different ideas like swapping out to a 90* truck valve, adding breathers, eliminating the pcv setup completely, reducing vaccum, etc.
Car is a '98 stock bottom end LS1 Trans am. 40,000 miles, CNC'd LS6 heads, 235/240 .648"/.609 - 111LSA cam, Fast 92/92, ported oil pump, headers, 3600 stall, all the other upgraded parts added while torn apart, pretty much what most people start out with. Nothing fancy, wish I would have gotten a few better parts but $$ held me back.
Before I upgraded to all the previously mentioned parts, there was some oil in the original intake, so being a newb a bunch of years ago I decided to add a catch can and that pretty much solved my problem. After I added all of the parts, I new obviously mpg's would go down and more oil would be used but those didn't matter. Now oil consumption seems crazy. Valve covers don't leak, but when I pulled my plugs, every one had oil on the threads about a half an inch up like oil ran down the outside of my heads and collected on the plugs.
My intake has oil in it, when I pull the throttle body off there is oil, catch can does collect some, first startup there is some blue smoke. Makes me think of valve seals, but they are new and have been on the car for 11 months, and 7 of those months was in storage. Maybe 2000 miles on all new parts. My pcv routing seems correct. Now I have center bolt valve covers, so the passenger side I had to add a fitting for a hose at the back since the front one is for clean air. Hopefully I can explain my routing easy:
-Tube off the throttle body is connected with a hose to the fitting on the front of the passenger valve cover (clean air)
-The back of each valve cover under the cowl area are tied together and end in a single hose at the top fitting of my catch can.
-Bottom fitting on the catch can is then connected to a pcv valve which then gets vacuum from being connected to the fitting on the intake, thus completing the loop. Hopefully the pic will help. Same routing, old intake.
I have read where people say there is way too much vacuum off the intake and this pulls a lot of oil mist into the intake, then gets burnt, causing detonation, excessive oil consumption, blue smoke, etc. I have seen some use a valve to regulate how much vacuum to reduce the intake from pulling in a lot of mist. I just tried this today and since I didn't have a vacuum guage handy, had to use my finger to see if I noticed a difference. I blocked a good 75% of the inside of the hose off and I swear it sucked just the same.
For almost 2000 miles, my oil looks pretty dirty. Always used Mobil 1 5w30. I fear a possible ring problem. I researched for a bit yesterday and came across someone mentioning to take your oil cap off and see if it pulls air in or pushes air out. Pulling was good, and luckily I tested this today and it pulled. I am really wondering what everyone else does with this problem, or how you have your pcv running on your car.
*** Odd thing today that I have no clue about. Alternator has been slowely weakening over the last few weeks and today finally it had to be replaced. Changed it over to a new 145 amp truck one. This is all I did to the car today. I ran the car before, diagnosed the problem, fixed it. I had just the front of the car on stands and the back on the ground. Car was like that for 4 hours. After I made sure everything was put back together I fired it up. Engine bay started smoking like crazy, a lot of blue smoke out of the tail pipes. So I shut it down quickly and tried to see what was up. Fired it up, same thing. I then put it on the ground after not finding anything and fired it up again, now no smoke at all from the engine bay or the exhaust. Took it around the block, a few 0-80 highway onramp blasts and the car runs like a champ, wideband reads all good.
So I am trying to mess with the pcv system and try to reduce that oil problem and see what is left after that. If anyone has any comment, suggestion, anything, I am all ears.
Thank You
-mark jr.
I have been trying to minimize my oil consumption for some time now and haven't really made any progress. Car uses around 1.5 qts per 1000 miles. I don't drive this car like a grandma so I know I will be using more than most people. From what I have read, I have the pcv routing correct. Read many different ideas like swapping out to a 90* truck valve, adding breathers, eliminating the pcv setup completely, reducing vaccum, etc.
Car is a '98 stock bottom end LS1 Trans am. 40,000 miles, CNC'd LS6 heads, 235/240 .648"/.609 - 111LSA cam, Fast 92/92, ported oil pump, headers, 3600 stall, all the other upgraded parts added while torn apart, pretty much what most people start out with. Nothing fancy, wish I would have gotten a few better parts but $$ held me back.
Before I upgraded to all the previously mentioned parts, there was some oil in the original intake, so being a newb a bunch of years ago I decided to add a catch can and that pretty much solved my problem. After I added all of the parts, I new obviously mpg's would go down and more oil would be used but those didn't matter. Now oil consumption seems crazy. Valve covers don't leak, but when I pulled my plugs, every one had oil on the threads about a half an inch up like oil ran down the outside of my heads and collected on the plugs.
My intake has oil in it, when I pull the throttle body off there is oil, catch can does collect some, first startup there is some blue smoke. Makes me think of valve seals, but they are new and have been on the car for 11 months, and 7 of those months was in storage. Maybe 2000 miles on all new parts. My pcv routing seems correct. Now I have center bolt valve covers, so the passenger side I had to add a fitting for a hose at the back since the front one is for clean air. Hopefully I can explain my routing easy:
-Tube off the throttle body is connected with a hose to the fitting on the front of the passenger valve cover (clean air)
-The back of each valve cover under the cowl area are tied together and end in a single hose at the top fitting of my catch can.
-Bottom fitting on the catch can is then connected to a pcv valve which then gets vacuum from being connected to the fitting on the intake, thus completing the loop. Hopefully the pic will help. Same routing, old intake.
I have read where people say there is way too much vacuum off the intake and this pulls a lot of oil mist into the intake, then gets burnt, causing detonation, excessive oil consumption, blue smoke, etc. I have seen some use a valve to regulate how much vacuum to reduce the intake from pulling in a lot of mist. I just tried this today and since I didn't have a vacuum guage handy, had to use my finger to see if I noticed a difference. I blocked a good 75% of the inside of the hose off and I swear it sucked just the same.
For almost 2000 miles, my oil looks pretty dirty. Always used Mobil 1 5w30. I fear a possible ring problem. I researched for a bit yesterday and came across someone mentioning to take your oil cap off and see if it pulls air in or pushes air out. Pulling was good, and luckily I tested this today and it pulled. I am really wondering what everyone else does with this problem, or how you have your pcv running on your car.
*** Odd thing today that I have no clue about. Alternator has been slowely weakening over the last few weeks and today finally it had to be replaced. Changed it over to a new 145 amp truck one. This is all I did to the car today. I ran the car before, diagnosed the problem, fixed it. I had just the front of the car on stands and the back on the ground. Car was like that for 4 hours. After I made sure everything was put back together I fired it up. Engine bay started smoking like crazy, a lot of blue smoke out of the tail pipes. So I shut it down quickly and tried to see what was up. Fired it up, same thing. I then put it on the ground after not finding anything and fired it up again, now no smoke at all from the engine bay or the exhaust. Took it around the block, a few 0-80 highway onramp blasts and the car runs like a champ, wideband reads all good.
So I am trying to mess with the pcv system and try to reduce that oil problem and see what is left after that. If anyone has any comment, suggestion, anything, I am all ears.
Thank You
-mark jr.
08-26-2012, 03:12 AM
#2
Car does have low miles.. I hate to say it but ur rings may be possibly going out.causeing bluesmoke ,and Mabe the oil consumption .do a leak down test to see where your engine stands.
08-26-2012, 09:32 AM
#3
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When your car was in the air engine was not level thus pushing oil.slightly past the rings causing it to smoke. But a leak down would be good. I upgraded to the ls6 valley cover and have 130,000 on the clock just did heads cam so I hope it will help my consumption.
08-26-2012, 09:52 AM
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Are you running the LS6 valley? You don't appear to be.. That would make things a little easier. The stock LS1 PCV routing is kind of a pain to deal with, IMO.
But agreeing this this guy ^^^ as well in doing a leakdown test. Especially if you have oil on the plugs. Check inside the intake too and see if there's an abnormal amount of oil in there. -Can rule out PCV system.
But agreeing this this guy ^^^ as well in doing a leakdown test. Especially if you have oil on the plugs. Check inside the intake too and see if there's an abnormal amount of oil in there. -Can rule out PCV system.
Last edited by bayer-z28; 08-26-2012 at 10:05 AM.
08-26-2012, 10:51 AM
#5
This may not be your issue but worth checking, I was having issues similar to yours and found that with my cam lift, , .660 my spring retainers on my dual springs were actually hitting the tops of my valve seals. I didn't figure this out till I tore the heads off and was checking everything. I found a couple springs from the seals laying in the oil that was pooled in the heads. I checked the distance between the spring retainer and seal and I only had around .005 " clearance. I did some calling and found out that most want at least .050" clearance between the retainer and seal. Had my guides cut and no more oil consumption or smoke. My lift is more than you have but not by much. Just my experience and it may help you and some others figure your issue out.
08-26-2012, 10:08 PM
#6
Definately some good ideas to check out. I have read up on the LS6 valley cover before I ever had problems and never saw any benefit to the swap. Routing the pcv isn't a problem, plenty of room, just if there is a different way of routing it, like turning the flow of air around. Fresh air off the driver valve cover and evac it out the passenger, or fresh air off the back of the cover and evac it off the front since when launching, oil will fly backwards, thus minimizing it being sucked through. I don't know, random ideas.
I have some free time this week and should be able to do a leak down test and see what results I have.
Came upon some info today. Something I should have done but never read anywhere about it. On the CNC heads, a few intake ports have the rocker bolt penetrate through and into the chamber. I read that you should put sealant on those just the same if you were building an older chevy motor where the head bolts went into the coolant. I never read to do that since I was getting my specs from a GM service manual. I torqued them down w/ ARP lube. You think that since I didn't use the sealant on the few bolts that it could be sucking at least some oil past the threads?
Kevin, first time I ever heard this mentioned. I will look into that this week also. Hopefully that isn't the problem, but it is definately worth checking out.
I will post back with some findings asap.
Thanks all for the info
mark jr.
I have some free time this week and should be able to do a leak down test and see what results I have.
Came upon some info today. Something I should have done but never read anywhere about it. On the CNC heads, a few intake ports have the rocker bolt penetrate through and into the chamber. I read that you should put sealant on those just the same if you were building an older chevy motor where the head bolts went into the coolant. I never read to do that since I was getting my specs from a GM service manual. I torqued them down w/ ARP lube. You think that since I didn't use the sealant on the few bolts that it could be sucking at least some oil past the threads?
Kevin, first time I ever heard this mentioned. I will look into that this week also. Hopefully that isn't the problem, but it is definately worth checking out.
I will post back with some findings asap.
Thanks all for the info
mark jr.
08-27-2012, 02:18 PM
#7
A few things I would do is first, if you must use M1, use a 40 weight. I perfer their 5W 40, it doesnt shear like their 5W 30 does. Also I would put a truck PCV valve before the catch can, the point of the valve is to restrict oil flow into the intake, I dont see it doing much of anything after hitting the catch can. To me it does sound like your rings though
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08-27-2012, 08:45 PM
#8
A few things I would do is first, if you must use M1, use a 40 weight. I perfer their 5W 40, it doesnt shear like their 5W 30 does. Also I would put a truck PCV valve before the catch can, the point of the valve is to restrict oil flow into the intake, I dont see it doing much of anything after hitting the catch can. To me it does sound like your rings though
First thing I am doing is a compression test on all cylinders. I cannot go by the gm specs since there are no stock parts left. If a cylinder seems different than the others I will do a leak down test. Just have to see what I come up with and then go from there. Hoping it is PCV, or at worst,valve seals. If it's rings I might as well start building a motor over winter.
08-27-2012, 11:20 PM
#9
been reading a lot of threads here on tech of people with similar problems. Unfortunately every person who says they will post up what fixed their problem never did as promised.
I ran across another member talking about thread sealant on the rocker bolts on CNC heads and the lack of may cause the problem. I wish I would have been thinking when I put the car back together but I didn't. My thinking is that it is very possible since the smoke on initial startup is minimal. Oil could be sucked past the threads through 4 bolts per head and could seep through when not running. It's like if you use penetrating oil to break a rusty bolt free. If the penetrating oil can make it past rust, why can't oil make it through w/ clean threads? This could explain oil on plug threads and mimic valve seals. Or it could be valve seals.
So I think I have a game plan:
-Pull covers, clean through hole threads and add sealant. Run the car a few times and see if there is a change.
-If no change, run a compression test on all cylinders, compare numbers and if there is an inconsistancy, time for leakdown test.
-Leakdown test and listen to where air is escaping from. If it's rings, time to rebuild iron 6.0 that has been in the basement for years.
Blk98Vert, Glad you re-posted back on here. I got an email from tech showing part of what you wrote, but when I got here, your post wasn't there and I was really wanting your input.
I re-read what you wrote and I think I gotcha now. Put the valve before the air flows into the catch can to restrict the amount of air entering. I am so tired and it just read odd in my head.
-I will post back what I find out after each test, hopefully I don't need to go through them all. I did just build a cylinder leak down tester out of a compression testing guage though, would like to use it, but not on my car, lol. Hopefully what everyone said and my long ramblings will help someone down the road.
I ran across another member talking about thread sealant on the rocker bolts on CNC heads and the lack of may cause the problem. I wish I would have been thinking when I put the car back together but I didn't. My thinking is that it is very possible since the smoke on initial startup is minimal. Oil could be sucked past the threads through 4 bolts per head and could seep through when not running. It's like if you use penetrating oil to break a rusty bolt free. If the penetrating oil can make it past rust, why can't oil make it through w/ clean threads? This could explain oil on plug threads and mimic valve seals. Or it could be valve seals.
So I think I have a game plan:
-Pull covers, clean through hole threads and add sealant. Run the car a few times and see if there is a change.
-If no change, run a compression test on all cylinders, compare numbers and if there is an inconsistancy, time for leakdown test.
-Leakdown test and listen to where air is escaping from. If it's rings, time to rebuild iron 6.0 that has been in the basement for years.
Blk98Vert, Glad you re-posted back on here. I got an email from tech showing part of what you wrote, but when I got here, your post wasn't there and I was really wanting your input.
I re-read what you wrote and I think I gotcha now. Put the valve before the air flows into the catch can to restrict the amount of air entering. I am so tired and it just read odd in my head.
-I will post back what I find out after each test, hopefully I don't need to go through them all. I did just build a cylinder leak down tester out of a compression testing guage though, would like to use it, but not on my car, lol. Hopefully what everyone said and my long ramblings will help someone down the road.
08-29-2012, 05:36 AM
#10
Yes. I didn't run a catch can on my 98 when I had it, but I had to redo my PCV system. The truck PCV did help a bit, but I wasn't really burning oil to begin with. On my GTO I will be installing a dual catch can setup. As it is right now Im only burning half a quart in 3K miles. I have the truck valve cover with the built in PCV on the drivers side.
08-29-2012, 05:54 AM
#11
which tool did you use to swap valvesprings......my 98 used to consume almost no oil at all, then i used the Tim's tool during my cam swap.....it got the job done, but what i didn't realize is that it caused the retainers to scratch the sides of my valve stems as it was pressing the spring down......this happened because the tool rests on the edge of the head and compresses the spring at an angle.....this didn't scratch every single one, but several were gouged pretty bad.....the stems that were damaged were probably the same ones that i had to compress a little further to get the locks on........pull a few valvesprings off both heads, grab the valve and manually pull it up, then run your finger down the stems, i bet you'll be able to feel that your valve stems are scratched up (the seals will still look normal, that's why this is so hard to diagnose).....wouldn't do me much good to replace the seals on mine unless i bought all new valves and pulled the heads.......i figure i'll just deal with the oil consumption until i can bolt on a set of aftermarket castings.
after i figured this out, i bought the Speed Inc spring tool....a tool designed like this is much better because it compresses the spring straight down instead of hinging it down at an angle from the side of the head.
after i figured this out, i bought the Speed Inc spring tool....a tool designed like this is much better because it compresses the spring straight down instead of hinging it down at an angle from the side of the head.
Last edited by jc98ss; 08-29-2012 at 06:47 AM.
08-29-2012, 06:18 AM
#12
+1 on a truck PCV before the can... Also, if you can, check your filter medium in the can. A lot of the low end ones don't actually trap any oil. I did a truck PCV and Saiku Michi duals, and switched to Rotella T6 (synthetic 5w40, very high ZDDP content) and went from burning as much oil as you to less than half a quart in 2500 miles so far (honestly, I think it might have just been the filter filling up).
08-29-2012, 10:14 PM
#13
Went to Autozone and looked through their books for 2001-2008 Silverados and they all said no part number for them. So I just kept the new replacement regular one I had. I swapped that to being in front of the can. Also changed the oil and went with M1 0w40.
I decided to pull the valve covers and pull the rockers that had open holes into the intake runners. There was definately oil in them and with 4 bolts per head that were open, I had 8 holes that were sucking oil through. I used brake kleen and q-tips and cleaned them, cleaned the bolts and used ARP thread sealant to all. I accidentally pulled the wrong rocker off and looked into the hole and it was black. I thought it was open but to my amazement it had a bottom. I could not believe how much oil got past the threads on a closed holes. Can't imagine how much was getting sucked past the open holes. Cleaned the spark plugs of oil and in a few days I will pull them again to see if they are oil free. Will also check for blue smoke on startup.
Hope that was my problem, but if not then it's time to move onto the next test. I looked at the valve seals to see if they were being contacted like previously mentioned and they were not.
I will have to look on my 06 Silverado at the pcv valve, I swear I saw one but books say there is none. Thought they were a 90* bend or something. Will look it up.
I did spot another problem w/ my pcv setup. When I swapped heads I had to get center bolt valve covers. The driver side had a vent on the back where the passenger didn't. So I had to add one to evac the system. Well the driver side vent has a baffle in front from the factory. The passenger one that I put in couldn't, so in the line coming off that vent I saw it was pretty wet. I need to figure something out to block it like factory and this should reduce the amount of oil that is being sucked in.
Thanks to all who replied, really helped me go over this problem and hopefully fix it and hope this can help others as well.
I decided to pull the valve covers and pull the rockers that had open holes into the intake runners. There was definately oil in them and with 4 bolts per head that were open, I had 8 holes that were sucking oil through. I used brake kleen and q-tips and cleaned them, cleaned the bolts and used ARP thread sealant to all. I accidentally pulled the wrong rocker off and looked into the hole and it was black. I thought it was open but to my amazement it had a bottom. I could not believe how much oil got past the threads on a closed holes. Can't imagine how much was getting sucked past the open holes. Cleaned the spark plugs of oil and in a few days I will pull them again to see if they are oil free. Will also check for blue smoke on startup.
Hope that was my problem, but if not then it's time to move onto the next test. I looked at the valve seals to see if they were being contacted like previously mentioned and they were not.
I will have to look on my 06 Silverado at the pcv valve, I swear I saw one but books say there is none. Thought they were a 90* bend or something. Will look it up.
I did spot another problem w/ my pcv setup. When I swapped heads I had to get center bolt valve covers. The driver side had a vent on the back where the passenger didn't. So I had to add one to evac the system. Well the driver side vent has a baffle in front from the factory. The passenger one that I put in couldn't, so in the line coming off that vent I saw it was pretty wet. I need to figure something out to block it like factory and this should reduce the amount of oil that is being sucked in.
Thanks to all who replied, really helped me go over this problem and hopefully fix it and hope this can help others as well.
09-24-2012, 11:00 PM
#15
Well I minimized it considerably. Went back and added sealant to the correct rocker bolts that were open to the chambers. Also eliminated the pcv system from evacuating off the passenger cover. I found that my added nipple placement to make it like the '98 pcv system was sucking a lot of oil due to no baffle covering the opening like a passenger cover, and oil splashing back when launching and easily sucked through due to no baffle.
I then blocked the passenger one I added off and it only evacs off the driver rear cover. So the passenger brings in fresh air and the driver evacs it. 1 way in, 1 way out...old school. Startup I don't see blue smoke like I did at all. I see nothing when I hang me head out the door. My bro says he sees an extremely small bit for a split second then nothing. I should pull my plugs tomorrow and see if oil is still there. If not then it was most likely the bolts not being sealed.
I then blocked the passenger one I added off and it only evacs off the driver rear cover. So the passenger brings in fresh air and the driver evacs it. 1 way in, 1 way out...old school. Startup I don't see blue smoke like I did at all. I see nothing when I hang me head out the door. My bro says he sees an extremely small bit for a split second then nothing. I should pull my plugs tomorrow and see if oil is still there. If not then it was most likely the bolts not being sealed.
09-24-2012, 11:33 PM
#16
I've had an issue with mine since the cam install or at least that's when I noticed it. My Pcv is the same exact setup as yours. Mine is something in the driver side head I believe bc it's only burning oil out of the drivers side header. I'm thinking valve seals but not positive. Only does it or only noticeable anyway once it's at operating temp. Thinking exhaust valve seal/ seals
09-25-2012, 10:48 PM
#17
I've had an issue with mine since the cam install or at least that's when I noticed it. My Pcv is the same exact setup as yours. Mine is something in the driver side head I believe bc it's only burning oil out of the drivers side header. I'm thinking valve seals but not positive. Only does it or only noticeable anyway once it's at operating temp. Thinking exhaust valve seal/ seals
09-26-2012, 12:50 PM
#19
since you say you see it out of the driver side I assume you have true duals then. Pull the plugs on that side and see if you have oil on the threads. I just did this today on mine and since I added the sealant to those bolts, my spark plugs were dry. Pull a valve cover off and check what Kevin mentioned a few replies previously. If not that, then I would assume it would be hard to tell just by looking at them. If you have cnc / ported heads, make sure those certain rocker bolts are sealed. I was surprised how much oil was seeping past overnight or getting sucked through accelerating. quick and easy to check.
