GTSSportCoupe
2LTE abuser
If pressure was getting past the valve guides, I'd imagine that oil would be passing back the other way and you'd see/smell it.
High blowby with good compression ...thoughts? (1 Viewer)
- Thread starter Fantom
- Start date
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RufusTheDufus
SILVER Star
RufusTheDufus
SILVER Star
RufusTheDufus
SILVER Star
A different thread over there indicates that this restrictor drops the valve cover vent's internal diameter from 12mm to 9mm. The only thing I can think of is that it creates higher internal crankcase pressure which will force more oil out of suspension in the crankcase air.
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Issue with creating more crank case pressure is the pressure will find the path of least resistenace and start pushing oil out the turbo and crank seals (worse than the situation Matt find himself in now).
Matt is there a splash plate in the valvecover? If so can you close up the opening or add to its legth to provide more distance for the oil to seperate? I knownthe 1hd guys bend the flapps up to prevent exsessive oil blowby.
My 4bd crateas a lot of crank case air movement but it does not put out any oil. The valve cover has a built in oil seperator and then I have my cyclonic 1.5L volume catch can that drains via a check valve back to the crank case. I have chacked my catchcan outlet a few times and its still bone dry.
I would be hesitant to replace the rings with compression numbers that good.
Matt is there a splash plate in the valvecover? If so can you close up the opening or add to its legth to provide more distance for the oil to seperate? I knownthe 1hd guys bend the flapps up to prevent exsessive oil blowby.
My 4bd crateas a lot of crank case air movement but it does not put out any oil. The valve cover has a built in oil seperator and then I have my cyclonic 1.5L volume catch can that drains via a check valve back to the crank case. I have chacked my catchcan outlet a few times and its still bone dry.
I would be hesitant to replace the rings with compression numbers that good.
- Thread starter
- #26
Well the slightly raised pipe didn't do anything, I still collect a bunch of oil. Next weekend I will try with the wastegate opened and test that out. I also have a valve cover from a 2LT that I will see if I can bolt on or make work somehow.
Thanks for the suggestions.
Thanks for the suggestions.
- Thread starter
- #27
Check the pics up top, I made my own baffled cover because the factory L one was even worse.
Fantom, let us know with the wastegate in open position if Crank case pressure decreases. Also, if you recall, I was over at your place to do a compression check because I did not know why I was getting lousy fuel economy. Well, I have been noticing black soot, oily water outside bottom of my quarter panel. I though mmm could the vent lines or filler neck be leaking? Went to put a paper towl in the cavity and it was filled with water, diesel and gunk on the bottom of the quarter panel. Seems the opening where the outer wheel well and quarter panel is letting water in because of rust and corrosion.
- Thread starter
- #29
Considering that in my case the factory diameter was creating too much restriction and causing the turbo drain to back up and not drain properly a unit like this would cause just more problems. This weekend I will try running it with the wastegate open and see if there is less visible vapour. I will also find a way of fitting the factory 2LT valve cover on (with the higher set vent) to see if that makes a difference. I keep going back to the design of them, The L, and 2L have low valve covers, yet as soon as they introduced a turbo they changed the valve cover and raised the breather way up. That can't be a coincidence, they must have encountered the same or similar issues or oil being splashed or force up - for whatever reason - and they chose this as a way of dealing with it. So does the 2LT inherently have too much blowby? What would happen if you put a 2L valve cover on a 2LT? would you be gushing oil out the breather the way I am right now?
GTSSportCoupe
2LTE abuser
Has the turbo you are using been rebuilt? I just did a google search 'turbo crank case pressure' and a lot of info came up. Seems like crank case pressurization is a somewhat common problem on turbo engines. As you said above, when the turbo seals begin to wear out, exhaust and intake pressure at the turbo can leak through the turbo seals into the turbo oil drain (to crank case). As you also mentioned, this would be more of a problem at boost, not idle. However, as I've seen the L engines do seem to have a lot of air movement at idle as well. Not so much significant positive air flow, but more just un-even air pulses.
So between your normally aspirated valve cover, crank case pressurization from turbo seals at boost, and lots of air movement at idle, I'd say you have some ideas to work with.
- Thread starter
- #31
The turbo I have is new, it was bought off one of the ebay shops in the US that brings them in from likely China, but it was one of the better ones. Having said that, I'm not holding my breath. I'll be testing those theories this weekend.
Thanks for the info, will update with results ....be they positive or negative....
Thanks for the info, will update with results ....be they positive or negative....
TLC Norway
woodwelder
I've had both 2L and 2LT engines, high and low milage, but none had excessive vent pressure, just for reference.
But my 2H (with turbo and ic) had increasing crank case pressures, and I added a catch can inline, with drain back to oil pan.
When I later got to dig into it, the turbo had bad seals.
And all the oil mist that the catch can didn't catch, ended up in the ic.
Lol, the ic turned out to be a big ass catch can, which secretly held allot of the oil I could not account for.
If you have a china (ct26?) Turbo, I would get it checked and replaced with a better unit.
I've not heard about one of them being soild.
Good luck!
But my 2H (with turbo and ic) had increasing crank case pressures, and I added a catch can inline, with drain back to oil pan.
When I later got to dig into it, the turbo had bad seals.
And all the oil mist that the catch can didn't catch, ended up in the ic.
Lol, the ic turned out to be a big ass catch can, which secretly held allot of the oil I could not account for.
If you have a china (ct26?) Turbo, I would get it checked and replaced with a better unit.
I've not heard about one of them being soild.
Good luck!
- Thread starter
- #33
Well after some testing I managed to get a few interesting results. I ended up running the truck with the wastage opened. Did not diminish the vapour or mist at idle or at revs (with no load). At least not visibly.
I ended up replacing the valve cover with the factory turbo unit and have been driving it around for the past two days with no oil in the catch can.
I am still undecided as to the condition of the turbo or the rings in different positions. I will test this further, but right now I can at least drive it without needing to haul a 5 gallon pale of oil.
I am looking at fitting a pressure gauge into he cab that is running off the valve cover vent. That way I can at least see if there is an increase at boost or not.
More testing to follow....
I ended up replacing the valve cover with the factory turbo unit and have been driving it around for the past two days with no oil in the catch can.
I am still undecided as to the condition of the turbo or the rings in different positions. I will test this further, but right now I can at least drive it without needing to haul a 5 gallon pale of oil.
I am looking at fitting a pressure gauge into he cab that is running off the valve cover vent. That way I can at least see if there is an increase at boost or not.
More testing to follow....
RufusTheDufus
SILVER Star
Interesting. Did you happen to snap any photos comparing the two valve covers?
- Thread starter
- #35
Not yet, but I will since this was just a temporary test.
The difference is significant as the turbo one has a chamber that is twice the volume of the non turbo.
The difference is significant as the turbo one has a chamber that is twice the volume of the non turbo.
RufusTheDufus
SILVER Star
I'm curious because I'm planning to add a turbo to my NA 2.4.
- Thread starter
- #37
Well after this little build I have learned a couple things. One is that the oil return out of the turbo needs to be as large and unrestricted as possible. The factory one on the 2LT was over 5/8" ID. And I figured out that anything smaller than that or with too many 90s restricts flow and causes the oil return to plug up and overflows the turbo, coming out of the seals.
You might encounter the same or similar issue with oil splashing up and being forced out of the breather. It cannot be a coincidence that the non turbo engines have low valve cover breathers and the turbo ones have it much higher. I'm guessing the engineers discovered that same issue, for whatever reason.
If you can get your hands on a fuel pump that has the boost compensator built in, that is a nice feature and totally changes the engine's performance. Running without it is much worse, At least on my engine (2.2L)
You might encounter the same or similar issue with oil splashing up and being forced out of the breather. It cannot be a coincidence that the non turbo engines have low valve cover breathers and the turbo ones have it much higher. I'm guessing the engineers discovered that same issue, for whatever reason.
If you can get your hands on a fuel pump that has the boost compensator built in, that is a nice feature and totally changes the engine's performance. Running without it is much worse, At least on my engine (2.2L)
- Thread starter
- #38
Well after a week of driving, and pushing it a bit harder with lots of highway and high boost type of situations, still no problems or oil in the catch can.
Next test will be plumbing the vent out of the catch can (which is currently set up to atmosphere) back into the post air filter, pre turbo spot. That will suck back all the vapour into the combustion chamber and we'll see if any oil follows.
Next test will be plumbing the vent out of the catch can (which is currently set up to atmosphere) back into the post air filter, pre turbo spot. That will suck back all the vapour into the combustion chamber and we'll see if any oil follows.
cruisedeisel
Toyota's for life
Good thread! I will be watching closely as I am almost ready to fire up my Home brew junk yard fab turbo today. Silicon bit and elbows will be here this week hopefully. Looks like I am now in the market for a 2lt valve cover.
