WTF, large amount of oil in the intake? (pics)
Your rings should not spin around on the piston for one, if that is happening you have a serious problem. The way you set them up when they go in the motor is how they stay. Reversion is one of the biggest ways for ls motors to get oil in the intake. When you go to a bigger cam that decreases manifold vacuum at then there is a better chance for reversion.
I would have to debate this, being a graduate of Reher Morrison Race Engine building school (www.rehermorrison.com) and having built motors for nearly 40 years & owned & managed one of the winningest high $$ bracket teams in the Eastern US.
Example: Drop an intake valve in cyl #7, but when you tear down you will see parts of the valve have traveled to nearly EVERY cylinder and caused damage...even in the few seconds it took to shut down. This is due to the reversion pulses throughout the intake runners. With composite intakes such as our LS based motors run, you will see sharapnel embeded in the intake runners (and if you reuse the intake chances are subsequent damage will occur when the pieces work loose). Oil most generally enters the intake via the PCV system or the fresh air intake (throttle body on LS motors) but can enter & be evenly distributed throughout the intake in several other ways as some of the more knowledgable posters earlier in this thread have pointed out. Valve seals, even when looking good (NEVER reuse valve stem seals as chances of a poor seal are high) can allow a substantial amount of oil into the intake runner of a cylinder head, and the reversion pulse will distribute it back into the intake. Same with a single ring/piston/cyl bore issue. Also, a bent or poorly sealing intake valve will casue tremendous reversion through the intake.
The big "air pump" that our motors are is not as simple as sucking air in one end & pumping it out the other.. Just do a google search on "intake reversion in race engines" to find slo-mo videos of IRL motors with reversion clounds pushing back out the injector inlets at 16,000 RPM! You would never in a million years think that can happen, but it does & even in our motors not spun over 6-7k, there is substantial reversion going on at all times in the mid-higher rpm range. Look at Reher Morrisons product listings & read how anti reversion rings are machined into intake spacers, etc. to reduce this (as it robs power by reducing velocity)...So, if the oil was entering through the catch can, the can would catch the majority of the oil, and he states it is not. The issue I suspect, is in the heads/valves....pull them & send them to a good machine shop for a professional valve job w/new seals (a broken timing chain no matter what rpm it occurs at will result in v-p interference). and I bet the issue dissapears. I truely do NOT think it is piston/ring related in his case.
The problem with internal media is that allthough it does a great job of trapping oil at first, as soon as it gets saturated droplets can & are pulled off it and exit the can into the intake. Not much mind you, but that is the reason I discontinued using it. The condesing effect is the most effective way to trap oil mist & vapors (turning them into droplets that can fall to the bottom of a can) and the more surface area with temprature differential, the more effective a seperator will be.
Example: Drop an intake valve in cyl #7, but when you tear down you will see parts of the valve have traveled to nearly EVERY cylinder and caused damage...even in the few seconds it took to shut down. This is due to the reversion pulses throughout the intake runners. With composite intakes such as our LS based motors run, you will see sharapnel embeded in the intake runners (and if you reuse the intake chances are subsequent damage will occur when the pieces work loose). Oil most generally enters the intake via the PCV system or the fresh air intake (throttle body on LS motors) but can enter & be evenly distributed throughout the intake in several other ways as some of the more knowledgable posters earlier in this thread have pointed out. Valve seals, even when looking good (NEVER reuse valve stem seals as chances of a poor seal are high) can allow a substantial amount of oil into the intake runner of a cylinder head, and the reversion pulse will distribute it back into the intake. Same with a single ring/piston/cyl bore issue. Also, a bent or poorly sealing intake valve will casue tremendous reversion through the intake.
The big "air pump" that our motors are is not as simple as sucking air in one end & pumping it out the other.. Just do a google search on "intake reversion in race engines" to find slo-mo videos of IRL motors with reversion clounds pushing back out the injector inlets at 16,000 RPM! You would never in a million years think that can happen, but it does & even in our motors not spun over 6-7k, there is substantial reversion going on at all times in the mid-higher rpm range. Look at Reher Morrisons product listings & read how anti reversion rings are machined into intake spacers, etc. to reduce this (as it robs power by reducing velocity)...So, if the oil was entering through the catch can, the can would catch the majority of the oil, and he states it is not. The issue I suspect, is in the heads/valves....pull them & send them to a good machine shop for a professional valve job w/new seals (a broken timing chain no matter what rpm it occurs at will result in v-p interference). and I bet the issue dissapears. I truely do NOT think it is piston/ring related in his case.
The problem with internal media is that allthough it does a great job of trapping oil at first, as soon as it gets saturated droplets can & are pulled off it and exit the can into the intake. Not much mind you, but that is the reason I discontinued using it. The condesing effect is the most effective way to trap oil mist & vapors (turning them into droplets that can fall to the bottom of a can) and the more surface area with temprature differential, the more effective a seperator will be.
When my heads were rebuilt its the only thing I did, except clean all that crap off the pistons. When I put the newly done heads back on, I had no more smoke trails when I nailed the gas pedal from a roll.
Thread Starter
TECH Regular
Joined: Dec 2004
Posts: 440
Likes: 0
From: Alpharetta, Ga
TC broke at 3500~4k rpms. Everything was fine before the TC failure. Oil pressure is likely due to a fubared O-ring install on my oil pick up tube.
Your rings should not spin around on the piston for one, if that is happening you have a serious problem. The way you set them up when they go in the motor is how they stay. Reversion is one of the biggest ways for ls motors to get oil in the intake. When you go to a bigger cam that decreases manifold vacuum at then there is a better chance for reversion.
I don't doubt the reversion process at all. All I was saying in that post was that bad valve seals allows oil from under the valve covers to go through the seals into the cylinders. It does that because of a massive, rather quick pressure drop when the engine is accelerated. Thats why engines with bad valve seals have smoke trails while driving, but idling or driving at steady speeds usually produce zero smoke.
When my heads were rebuilt its the only thing I did, except clean all that crap off the pistons. When I put the newly done heads back on, I had no more smoke trails when I nailed the gas pedal from a roll.
When my heads were rebuilt its the only thing I did, except clean all that crap off the pistons. When I put the newly done heads back on, I had no more smoke trails when I nailed the gas pedal from a roll.
A sure sign of bad valve seals is let an engine sit & idle for 5 minutes or so and then rev it....lot's of smoke that normally is not seen. Rings will show by revving an engine repedatly and it starts to smoke bad.
100% correct.
Smoke when under acceleration is usually ring related as the intake manifold pressure will drop substantially. Valve seal smoke comes when the intake manifold is at it's highest vacume (idling, low RPM running, or deceleration from high RPM's.)
A sure sign of bad valve seals is let an engine sit & idle for 5 minutes or so and then rev it....lot's of smoke that normally is not seen. Rings will show by revving an engine repedatly and it starts to smoke bad.
Smoke when under acceleration is usually ring related as the intake manifold pressure will drop substantially. Valve seal smoke comes when the intake manifold is at it's highest vacume (idling, low RPM running, or deceleration from high RPM's.)
A sure sign of bad valve seals is let an engine sit & idle for 5 minutes or so and then rev it....lot's of smoke that normally is not seen. Rings will show by revving an engine repedatly and it starts to smoke bad.
So, I fixed bad valve seals and the trail stopped 100%. I can't get my engine to smoke no matter what I do to it now.
TECH Apprentice
Joined: Oct 2007
Posts: 302
Likes: 20
Don't take my word for it - call Total Seal, Ackerly & Childs, Speed Pro or any of the other ring manufacturers. They'll tell you the same thing.
Last edited by Busted Knuckles; Feb 15, 2009 at 09:06 AM.
But..when I was getting a monster trail of bluish-white smoke when I would nail my throttle from a roll (50-60mph punch), it was my only issue with the car. I never once had smoke at idle, partial accleration or sitting in traffic idling after 1 hour of driving. No smoke, ever. Only when mashing the pedal from a roll. This is why I took my heads off for a rebuild, my local shop told me my valve seals were bad. When my heads were rebuilt and 3-4 valve seals on each side, I even found the little springs that hold them in during an oil change on my oil pan bolt. He rebuilt the heads with all new springs and new seals, they were put back on..........and the only thing that did not occur anymore was that smoke trail I made after mashing the pedal from a roll.
So, I fixed bad valve seals and the trail stopped 100%. I can't get my engine to smoke no matter what I do to it now.
So, I fixed bad valve seals and the trail stopped 100%. I can't get my engine to smoke no matter what I do to it now.
That could also be valve seal caused/guide caused as well. Especially since the head work & new seals cured it, but at extended idle it should have started smoking as well as an indicator. No smoke is a good thing!
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo Thread Starter
TECH Regular
Joined: Dec 2004
Posts: 440
Likes: 0
From: Alpharetta, Ga
Bit of an update. I put everything back together and idled the car for 15~20min. I then pulled the TB off and looked into the intake manifold again. There was oil residue on the left and right side of the intake manifold that ran the full length of the manifold in front of the openings. The oil is definitely coming in through the intake ports somehow. There was no reversion before and I don't see how "all of a sudden" there could be reversion now. I will have a leak down test done and the valvestem seals inspected. I really don't think its my valvestem seals. Whatever, the process of eliminaion will begin soon.
BTW, there is no smoke at idle.
BTW, there is no smoke at idle.
Bit of an update. I put everything back together and idled the car for 15~20min. I then pulled the TB off and looked into the intake manifold again. There was oil residue on the left and right side of the intake manifold that ran the full length of the manifold in front of the openings. The oil is definitely coming in through the intake ports somehow. There was no reversion before and I don't see how "all of a sudden" there could be reversion now. I will have a leak down test done and the valvestem seals inspected. I really don't think its my valvestem seals. Whatever, the process of eliminaion will begin soon.
BTW, there is no smoke at idle.
BTW, there is no smoke at idle.
When doing the leak-down test listen carefully in each intake valve (cyl head intake ports) for leakage. I suspect a valve or two not sealing totally.
Thread Starter
TECH Regular
Joined: Dec 2004
Posts: 440
Likes: 0
From: Alpharetta, Ga
So if this oil is coming in through my combustion chambers via some valves not totally sealing, wouldn't that mean my oil rings are junk? How could that much oil make it into the combustion process, at idle no less, to be then distributed through the intake manifold?
BTW, not that it matters but I did a compression check and every cylinder was between 195~203psi.
BTW, not that it matters but I did a compression check and every cylinder was between 195~203psi.
Bit of an update. I put everything back together and idled the car for 15~20min. I then pulled the TB off and looked into the intake manifold again. There was oil residue on the left and right side of the intake manifold that ran the full length of the manifold in front of the openings. The oil is definitely coming in through the intake ports somehow. There was no reversion before and I don't see how "all of a sudden" there could be reversion now. I will have a leak down test done and the valvestem seals inspected. I really don't think its my valvestem seals. Whatever, the process of eliminaion will begin soon.
BTW, there is no smoke at idle.
BTW, there is no smoke at idle.
I was under the impression that you replaced all of your valves when you did your "freshen-up"? If not, you definitely need to get that done, replace ALL the valves. Even if a valve just lightly kissed the piston, that valve is most definitely weakened, even if it didn't leave any major marks on the piston, and it may even seal still, but weakened. I have seen this happen before, and then the valve head breaks off. This is why a timing chain break is so costly. Also, PLEASE do not get the valve stem seals "inspected" have them REPLACED. They're 36 dollars.
Good luck with whatever you decide to do.
Thread Starter
TECH Regular
Joined: Dec 2004
Posts: 440
Likes: 0
From: Alpharetta, Ga
^ Every single valve in my heads are brand spanking new gm valves and the seats were all touched up. I did not lap the valves in though. Richard @ WCCH told me I would be fine after ~10min of running since he freshened up the seats when he had the heads. A leak down will be done and if it comes back good the valve stem seals will be replaced.
But I'm telling you, the only time my tailpipes would smoke AT ALL was when I nailed it from a roll. I never had any idea I had issues until a friend was behind me and said I smoked him out when I took off. If I had smoke at idle and other times, it would have prompted me to get the issue fixed much earlier.
Thread Starter
TECH Regular
Joined: Dec 2004
Posts: 440
Likes: 0
From: Alpharetta, Ga
It would tell me if a valve wasn't sealing correctly assuming my rings are good to go. I think my rings are fine and since the top end has been rebuilt and the bottom end hasn't(only 15k miles), a cyl. leak down out of spec would tell me a valve isn't sealing properly would at least would lead me to believe that it is the cause of this oil in the intake mani due to reversion...or at least that what I am being told in this thread. If the leakdown comes out good, the valvestem seals will all be replaced.
Ok i've been following this thread for awhile. So how do you guys figure that the intkae does not toung the valley? It sits right on top of it right? I have a dodge ram with this same problem just not near as bad as 1.8's. My ram has bad intake gaskets and sucks oil up though them and burns it. Why could this not be the problem on this car? Could your low oil pressure be cam bushing related? If it is than there is the possability that there may be extra oil in the valley. Not trying to rub anybody the wrong way or anything but it may be something to look at.
Staging Lane
Joined: Dec 2006
Posts: 55
Likes: 0
It would tell me if a valve wasn't sealing correctly assuming my rings are good to go. I think my rings are fine and since the top end has been rebuilt and the bottom end hasn't(only 15k miles), a cyl. leak down out of spec would tell me a valve isn't sealing properly would at least would lead me to believe that it is the cause of this oil in the intake mani due to reversion...or at least that what I am being told in this thread. If the leakdown comes out good, the valvestem seals will all be replaced.
When you restarted the motor was the pcv system connected at all? If so let both lines vent to atmosphere, plug the vacuum source and try again. If it fails, replace the valve seals.
There is always vacuum in the intake runner. I can imagine if you have a really bad seal or one that is not seated all the way it would drink large amounts of oil. When you plulled the intake were some of the runners oilier than the others. If so, then you probably have your source.
Ok i've been following this thread for awhile. So how do you guys figure that the intkae does not toung the valley? It sits right on top of it right? I have a dodge ram with this same problem just not near as bad as 1.8's. My ram has bad intake gaskets and sucks oil up though them and burns it. Why could this not be the problem on this car? Could your low oil pressure be cam bushing related? If it is than there is the possability that there may be extra oil in the valley. Not trying to rub anybody the wrong way or anything but it may be something to look at.
If you lift the intake off, the valley cover is sitting there all by itself. The oil is inside/under it.
Right......