19963.4lsr5
New member
What you described can also be bad valve stem seals. But you had standing oil in your intake, and I doubt your oil is overfilled.
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Need help with mysterious major oil leak
- Thread starter Outrider
- Start date
That's what I'm afraid of - bad valve stem seals on the passenger side. There is no oil in the large (9/16"-5/8" dia) rubber tube (vacuum or pressure?) coming up vertically from the rear of the driver side VC. There was a little oil in the tube from the PCV valve to the intake on the passenger side. As well as a little oil in the downstream side of the aftermarket PCV valve I just removed and replaced with an OEM one. So far, it is looking like the substantial amount of oil in my intake is coming from the PCV valve. I am hoping my new OEM valve corrects, or at least minimizes that. If it doesn't, I am either making or buying a catch can, to help with the symptoms, and allow me to drive it until I get a job and can replace the vehicle.
My oil level is dead nuts at the top of the mark on the dipstick, and not over. I monitor that closely, with this thing smoking. What is interesting is that the vehicle has to be nearly perfectly level for the dipstick to read correctly. If it looks "close enough" to level, like on a driveway, the reading will be off noticeably. That is screwing with my brain, too. I can only read it on while it is parked in my basement. Also, it has to set for about a half hour after running to get a good reading. 5-10 minutes after shutting off, doesn't cut it.
Is there any other way all that oil can get sucked into my intake, than through the PCV valve? Why does it not smoke on startup 5-15 minutes after shutting down, but it does after an hour or more? It is like oil is being slowly sucked into the engine while it is not running.
I don't have the money for a leak down tester. Otherwise, I would get one and eliminate the mystery. But this is about the only time I would ever use one, and I'm not into throwing money into new tools that I would rarely use.
Anyone see why this is so perplexing and frustrating? Smoke is never good, the cause is a real mystery based on all of the symptoms, and I am not tearing my engine apart again. I just spent 80 hours working on this thing, and I am utterly sick of it.
One other detail I have forgotten to include - I replaced the passenger side valve cover with an aftermarket one during the timing belt job. When re-installing that VC, I didn't notice that it wasn't setting perfectly flat, and I started torquing the bolts, which cracked the outermost, rearmost bolt lug. I replaced the VC with this one:
https://www.rockauto.com/en/moreinfo.php?pk=4199658&cc=1357455
It is also a possibility that this VC is either poorly designed, or defective, and allowing more oil out of the PCV valve than it should (as in the baffles, etc., in the top of it, not working correctly).
Just trying to include all information that may help someone recognize what could be going wrong here.
https://www.rockauto.com/en/moreinfo.php?pk=4199658&cc=1357455
It is also a possibility that this VC is either poorly designed, or defective, and allowing more oil out of the PCV valve than it should (as in the baffles, etc., in the top of it, not working correctly).
Just trying to include all information that may help someone recognize what could be going wrong here.
It did not, not that I ever noticed. And this smoke on startup is quite noticeable. That's what is really throwing me for a loop on this - the coincidence on the time frame with my timing belt change, and my resulting oil leak (which is now solved).
The only thing that really changed, that I am aware of, was a new valve cover. I replaced the then almost new aftermarket PCV valve, then replaced it again, with the same, after seeing smoke. Yesterday, I replaced it with a new OEM PCV valve. I am about to fire it up for an errand and find out if that helped any.
Edit: I see that ^^ and I were just typing at the same time.
Another update:
This is blowing my freaking mind. With a new OEM PCV valve in it, I just fired it up. Just a tiny bit of smoke for a few seconds. Not the huge plume I was getting. Apparently, OEM PCV valves let less oil through than the aftermarket ones I had. The real test will be after I drive it some, turn it off, let it set for at least an hour, then fire it up again. That is the scenario when the smoke really shows itself.
Heading out now for errands, and I will have another update this afternoon.
This is blowing my freaking mind. With a new OEM PCV valve in it, I just fired it up. Just a tiny bit of smoke for a few seconds. Not the huge plume I was getting. Apparently, OEM PCV valves let less oil through than the aftermarket ones I had. The real test will be after I drive it some, turn it off, let it set for at least an hour, then fire it up again. That is the scenario when the smoke really shows itself.
Heading out now for errands, and I will have another update this afternoon.
19963.4lsr5
New member
I don't like Dorman for anything. I wonder if the oil baffle in that valve cover is not as good. If Toyota has a current patent on that oil baffles design than Dorman isn't allowed to copy it.
It may be worth getting a used one.
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It may be worth getting a used one.
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Coward
New member
I think it is highly unlikely that the PCV valve or the new valve cover are the issue. However the catch can idea will give you an idea if you have a significant amount of oil going to the intake and B) if that is the cause it should stop smoking at startup.
Another thought is the intake manifold. Removing the plenums is it possible that you removed any unnecessary nuts and bolts? Perhaps the manifold seal was broken? Not likely the cause but still.
Same here. If I had been able to find a now or used OEM one at the time, or repair my cracked one, I would have. I went with the only option I could find at the time, and in that time frame. If I don't find a cause/cure soon, I will try to find a used one. I may even try to repair my old one, but that likely won't work, and it would be a whole lot of work for nothing.
Time will tell, after I let it set for over an hour before I start it up again. So far, so good, though. After I let it set a while and if it doesn't smoke like crazy, then I will know that the new OEM PCV valve was definitely a major factor. It very well could be a "stacking of tolerances" (engineering term), where a few things being off a little, here & there, added up to a major cluster F.
I'm pretty sure everything on the intake manifold is squared away, but it is quite possible that I overlooked something hidden, multiple times. I wish someone who was intimately familiar with T4R's lived close to me here in NW metro Atlanta, and could just take a good visual of the top of my engine.
I am toying with the idea of rigging up a catch can with an air compressor filter. If this problem persists, I will probably do that (if I don't just buy that $40 one shown above). I am a cheapskate and hate paying money for something I can rig up myself, cheaper. Same reason I refuse to pay anyone money to work on my vehicles (except for installing tires and doing alignments).
Edited: I did replace the manifold gaskets during my leak repair.
thegipper
New member
I still think you need to a leak down test. It's quick/easy and you'll know for sure if your valve stem seals are leaking or if there is something else going on (HG, worn rings etc).
If the leak down test goes good then you at least know there is nothing seriously wrong with your engine and it must be some other goofy thing causing the smoke show.
If the leak down test goes good then you at least know there is nothing seriously wrong with your engine and it must be some other goofy thing causing the smoke show.
I know. If I had expendable cash, I would get a leak down tester. But this would likely be the only time I ever used it. That's why I am trying to save that as a last resort. Plus, I really don't want to learn that the interior of my engine needs serious work.
LittleCaesar
New member
This is good news. These cars love their OEM parts. Now save some $$$ for the catch can and some PCV hose from an auto parts store and install. Then check after a couple of days. Hopefully you will only have to empty the catch can maybe once a month. But the manifold should then be oil free.
I still say it is the valve stem seals, probably exhaust. You probably could hear the valve(s)
in question at the tailpipe. But as [MENTION=138943]thegipper[/MENTION] says, only with a leak down tester and a good compressor can you pinpoint the exact problem.
I still say it is the valve stem seals, probably exhaust. You probably could hear the valve(s)
in question at the tailpipe. But as [MENTION=138943]thegipper[/MENTION] says, only with a leak down tester and a good compressor can you pinpoint the exact problem.
I thought I was about to update that the problem was solved by a new OEM PCV valve. After some short errands this morning, letting it set for 1.5 hours, and starting it up again, the smoke was extremely minor, and I thought it was still just getting rid of the residual oil in the intake, with the problem solved.
I took it on another, longer drive, to confirm. Got home, let it set for another 1.5 hours, and just started it. There wasn't a huge plume of smoke, but there was enough for it to still be worrisome. The problem was helped some by the new OEM PCV valve, but not eliminated.
Now it appears that either my valve seals just started appear to be a problem at the same time I was replacing my timing belt, or that the Dorman valve cover is a poor design. The problem is a little better, but still there.
Time for me to install a catch can now. I am not going to screw around with buying a leak down detector that I likely use only once, nor replacing my valve seals. At least not for quite some time. I am burned out tearing my engine apart. And broke. I don't want to spend the time trying to find a used valve cover, then likely driving to go take one off in a junkyard, and paying yet more money, only possibly find out that it didn't solve the problem either.
The catch can should at least help with oil being burned. Treating the symptom, instead of the cause - I know. But at this point, that is all I am going to do.
Thanks for the help and advice on my problems, everyone. :thumb:
I took it on another, longer drive, to confirm. Got home, let it set for another 1.5 hours, and just started it. There wasn't a huge plume of smoke, but there was enough for it to still be worrisome. The problem was helped some by the new OEM PCV valve, but not eliminated.
Now it appears that either my valve seals just started appear to be a problem at the same time I was replacing my timing belt, or that the Dorman valve cover is a poor design. The problem is a little better, but still there.
Time for me to install a catch can now. I am not going to screw around with buying a leak down detector that I likely use only once, nor replacing my valve seals. At least not for quite some time. I am burned out tearing my engine apart. And broke. I don't want to spend the time trying to find a used valve cover, then likely driving to go take one off in a junkyard, and paying yet more money, only possibly find out that it didn't solve the problem either.
The catch can should at least help with oil being burned. Treating the symptom, instead of the cause - I know. But at this point, that is all I am going to do.
Thanks for the help and advice on my problems, everyone. :thumb:
LittleCaesar
New member
With the $$$ being tight at the moment, that is the route I would take. I would also check out all the junkyards near you and see if they have a used passenger side valve cover as long as it isn’t cracked.
Post a pic or two when you get the catch can installed.
Post a pic or two when you get the catch can installed.
I will post pictures, if I think of it. I am going to rig up an air compressor filter. Trying to do this for under $20.
I could try to braze-"weld" my current, cracked OEM valve cover. I have had great success doing that before, but I haven't tried doing that yet on cast aluminum. I doubt it would hold, and I doubt I could keep the bottom sealing surface flat enough to seal properly. That wouldn't cost me much, except for a lot more wasted (likely) time. I will check with local junkyards, though.
phattyduck
Elite Member
There could just be residual oil in the intake manifold. Give it a couple more days before committing to anything.
A PCV valve is a fairly tuned device. It only should allow air to pass during certain amounts of engine vacuum (not too much, not too little!). The other valve cover vent goes to atmospheric pressure to allow fresh air back into the engine (in one head, through the block and back out the other) to flush out acidic vapor inside the engine when the PCV is allowing vacuum to pass. The non-PCV vent side can also exhaust excessive blow-by under high engine loads.
If the problem is the valve guide seals, a catch can will do nothing for it - and leaking valve stem seals wouldn't get oil anywhere other than the back of the intake valves.
-Charlie
A PCV valve is a fairly tuned device. It only should allow air to pass during certain amounts of engine vacuum (not too much, not too little!). The other valve cover vent goes to atmospheric pressure to allow fresh air back into the engine (in one head, through the block and back out the other) to flush out acidic vapor inside the engine when the PCV is allowing vacuum to pass. The non-PCV vent side can also exhaust excessive blow-by under high engine loads.
If the problem is the valve guide seals, a catch can will do nothing for it - and leaking valve stem seals wouldn't get oil anywhere other than the back of the intake valves.
-Charlie
That's what I was kind of thinking, but not certain. I didn't see how leaking valve seals would force oil upward, through the top of the valve cover (and hence PCV valve). With that in mind, either something else is screwed up in my system, or my new aftermarket valve cover is not doing its job properly (interior baffles, etc.). So, a catch can would treat the symptoms of a faulty valve cover. Rigging up a catch can is probably a little cheaper, and definitely less work than finding, removing from a junkyard, and then installing on mine, as well as probably definitely a good bit cheaper. Something to do until I am able to find a used valve cover.
It now appears to be two separate problems, at worst. Leaking valve seals is something I would just live with, until I sell this thing. But I have to deal with the engine smoking, which appears to definitely be caused by either a faulty valve cover or some other plumbing on top of my engine being screwed up.
Edited: But, I will wait a few days before doing anything, to give residual oil a chance to blow through.
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I don't have the cash right now, but a local junkyard will sell me a used valve cover for $100, if I bring them my cracked one, as a partial trade. He said he would put my cracked one back on the junk engine they have.
I paid $125 for this Dorman one that might very well be causing this smoke problem. If only I had know that I could have gotten another OEM one for $100 (I am thumping my forehead now)...
Again, I will wait a few days and see if the residual oil blows through and this clears up.
I paid $125 for this Dorman one that might very well be causing this smoke problem. If only I had know that I could have gotten another OEM one for $100 (I am thumping my forehead now)...
Again, I will wait a few days and see if the residual oil blows through and this clears up.
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