can anyone tell me the solution to a dipstick popping open at full boost/full throttle? its happened twice since last easter...the second time last night sprayed oil all over my windshield(vented hood). I have a catchcan where the valve breather originally goes. but the pvc valve is still connected the the intake manifold. the PVC is good. any help would be good.

Well, and easy and quick fix would be ductape. No idea how to actually stop the problem though. (i'm not turbo yet )

** Current status: 9 bent valves. and it only had 6,000 miles on it. i hope the replacement goes well. **

Lots of expensive parts, and still slow! Oh wait, it has to run to go fast.

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Pinch the top of the tube the dipstick slides into slightly. Problem solved.

Mike D
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I've seen that video....and as far as using anything to keep it closed...I wouldnt think that would be a good idea...seeing how its popping because of pressure I'm sure. and if pressure doesnt have an escape route it'll find one. is there anyone turboed that has experienced this?

Mike D
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i would recomend venting your valve cover better. i have both ports going to a can with 1/2" lines and i vented the can. a 5/8" drill bit right in the top of it. no more pressure for me.

got that megasquirt!

not sure if this will work but it is what i plan to do to my car soon.


I have the the jez catch can that jegs sells

i plan to have the drain line return to the oil pan at about the same spot my turbo drain line dumps. This i think would also help in your case cause it would allow the dipstick from popping up by allowing the oil pan to vent if there is to much pressure(possibly)


note that is just a thought

___________________________________________________________________________
13psi on a built bottom end with a stock now mtx, check mate.

I'm just going on a hunch here but I dont think venting the oil pan would be a good idea seeing how there is supposed to be pressure? Venting it would eliminate the pressure woundlnt it?

I tried to do the samething with my oil pan. DON'T DO IT. There is too much oil spray and pressure that even though i had a peterson catch can with all kind of baffling in it ,it still forced oil out of the filter on the catch can.

OOoo, good thing i posted that then. Ok bad idea, lol.

___________________________________________________________________________
13psi on a built bottom end with a stock now mtx, check mate.

Total has already told you how to fix the problem. Pinch in the top of the dipstick tube.

I have the 2 port design catchcan(like greddy) I only have a hose from the valve cover breather on the valve cover stright to the catch can with a filter on the other end...I then have the PVC in its stock location....I was plotting that running a hose from the valve cover(breather) to the catch can on one port and from the second runninga hose to a check valve and then to the intake manifold...is this the same you are saying paul?

could you draw a diagram of what you think will work?

I think this is what he is saying! Please correct me if I am wrong:

--------------------


- 05 Subaru STi
- 97 eclipse gs (289whp w/ 276tq)

Yep, that's exactly correct. As long as the catchcan itself doesn't have any vents/breathers on it, that system should work quite well.


-http://www.symtechlabs.com/-

awesome guys....that diagram should be posted in the wiki...I dont know how to do it or I would.

--------------------


- 05 Subaru STi
- 97 eclipse gs (289whp w/ 276tq)

well as I've learned from forums...sometimes people get things mixed up(valve cover filter port vs. pvc port) so the only real way to get the exact idea of what people are saying is a diagram or picture...not that I think paul was confusing anything...he's helped me a great deal through out my experience with this car. and so have many other people which I appreciate all of your help. thanks for the diagram Aggression.I have re-routed my catch can and so far no problems but like I said it only happened twice...and I've been turbo since easterish...and i've daily driven it most of the time. but if I do encounter any problems I will be sure to chime back in and let everyone know.

that sounds like it will work well until you hit boost. then when you need crankcase evac the most, its not there. thats when the dipstick will pop out and the breather filter will spill oil. i think i found the only good use for the e-ram fan and im thinking of sucking the perss. from the catch can with a check valve and puting it on a wot switch. what do you guys think?

got that megasquirt!

A good motor will blow out a bad dipstick, a bad motor will blow out a good dipstick...

Check to see if smoke is coming out of there at idle. what is going on is either your rings are having sealing issues or your crankcase evacuation system is not setup for boost and it is building up and the dipstick is acting as a vent.

_ _ _ _ _ _ _ _ _

96 Black ESi
91 Red TSI AWD (RIP)
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Hey guys, i dont post alot of topics up on this side, just serch to find help, but i couldn't help myselft when i ran into this. the whole thing with the oil pan being vented, deff. not a good idea. i blew out my rear main seal because of possitive pressure in the crank. basically when you boost, the possitive pressure (psi) in the intake manifold overcomes the stock 420a pcv valves, and starts dumping boost into your crank case. it is a good idea to run both ports on your VC to a catch can and just block off the port on the intake mani. where the pcv would usually go, but what makes this even better is running a line from where you would normaly vent your catch can to the inlet of your turbo(not the compressor, but where the intake filter sits.) weld a nipple on that pipe ( if you are using a pipe for your air filter.) there is constant vacuum there, so it will pull the fumes from the catch can and run them back into the motor so they can be burned. oil is trapped in the can, if you have a descent catch can. that should solve your problem. or just use a eagle talon tsi PCV valve and use it instead of the stock 420a valve. it will act as a check valve and under boost it will block of the crank case, not allowing boost to enter it. i hope i didnt confuse anybody with this post.
good luck

I'm having this same problem as well. I am using the Talon TSI pcv valve, and i have the breather side of the valve cover to a catch can. my dipstick tube keeps comin out of the hole on the block. Any suggestions, I want to try to setup the catchcan the way it is explained in this thread. But is the a greater way to get rid of excess pressure? I'm runnin about 20psi on a built motor.

98 GS
Super 17c Turbo, Portfueler, Je pistons, Eagle rods, Etc.

The Turbo PCV is known for failing....get rid of it and use the stocker.

If you dipstick tube is comming out of the block then it sounds like the tube is not bolted into the block like it is supposed to be.

Crankcase pressure will always build up inside the motor unless you have some means of relieving it. Remember, yours pistons have two sides -- they create pressure on both sides.

The PCV only works under high vacuum situations, like idle and decel. Otherwise, it is suppose to be closed to prevent positive pressure entering. Running a check valve will help prevent boost from pressurizing the crankcase further, but it still doesnt allow crank case pressure that builds up normally any where to escape. Thats why your dipstick tube is getting blown out (and also why supras like to blow front main seals)

the v8 guys have run vacuum pumps on track cars to pull that crankcase pressure out -- having the crankcase under constant vacuum also allows the rings to seal better and reduces drag in the motor...high horsepower v8 cars will see gains as high as 40-60hp using a vacuum setup. (as well as having much cleaner oil).

Mechanical vacuum pumps are great because theyre pulley driven and give a linear relation in motor speed and how much vacuum is pulled, but theyre expensive and need frequent rebuilds. Electronic vacuum pumps can be had for less (smog pumps), but they dont tend to last long and its difficult to set them up so that they draw more vacuum at higher rpm/boost and less at lower rpm/boost.

Another means to have a constant vacuum source is using slashcuts in the exhaust -- they generate vacuum through the bernoulli effect. This eliminates crankcase pressure and keeps the crankcase in vacuum. Moroso, Summit, Mr.Gasket, etc all sell kits that include slashcuts and check valves (to keep exhaust from entering the crankcase in case of a backfire).

The supra crowd picked up on this method a while back too





You can either just burn off the blow-by in the exhaust, or run a sealed catch can inline to avoid smoke from buring blow-by

The problem with using the pre-turbo intake as your vacuum source is that very little vacuum is generated pre turbo unless you have a very restrictive intake.

You can try to just vent the crankcase to atmosphere, but it doesnt appear to be an adequate means of relieving crankcase pressure -- take a look at the supras who blow front mains frequently and most of them will just be venting the crankcase instead of having some type of vacuum source to pull pressure out

added benefit of having the crankcase in vacuum is that any oil leaks will suck in instead of blowing out -- meaning they will either be sealed or suck air in instead of blowing oil out.




With my most recent build, I was researching all the different ways Ive seen pcv and catch can setups and the exhaust evac setup seems to be most ideal: constant state of vacuum that increase as the engine is driven harder (more exhaust flow creates more vacuum) and total isolation of blow-by and crank case gasses from the intake tract

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

Will this evacuation system work for a car with an open downpipe? I'm thinkin about doing this on my car.

98 GS
Super 17c Turbo, Portfueler, Je pistons, Eagle rods, Etc.

If you are having problems with a stock pcv valve then try a supra pcv. A 93 through 97 turbo supra pcv valve has very close to the same dimensions as ours except they are straight not 90 degrees. No biggee just run a longer hose to curve it. I have been using one for about 2 years now and love them compared to our stock one.


Also i have my catch can set up a little bit different than most people . I attached the catch can(with a breather) where the pcv valve normally goes. Then i attached the pcv valve where the breather tube used to be. This way you have a bigger outlet for the crankcase to let pressure out while still maintaining a pcv system.
Look in the pic at the blue hoses to see what i mean.

Originally posted by Crab1092
If you are having problems with a stock pcv valve then try a supra pcv. A 93 through 97 turbo supra pcv valve has very close to the same dimensions as ours except they are straight not 90 degrees. No biggee just run a longer hose to curve it. I have been using one for about 2 years now and love them compared to our stock one. Also i have my catch can set up a little bit different than most people . I attached the catch can(with a breather) where the pcv valve normally goes. Then i attached the pcv valve where the breather tube used to be. This way you have a bigger outlet for the crankcase to let pressure out while still maintaining a pcv system. Look in the pic at the blue hoses to see what i mean. .jpg

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

Do you drive your car with the timing cover off like that!?

__________________________________________
All that is necessary for evil to prevail is for good men to do nothing.- Edmund Burke

HRC Stage IV

Well its a track only car. Also the whole cover isnt off. It is cut where the head bolts to the block.

Also i wasnt saying that my setup is better than using a pump to vacuum the crankcase. However i do fully believe it is sufficient for me, as well as most other. Even at 27 psi pushing close to 400whp through my engine i have never had my dipstick pop open or any problems with my rear main or valve cover leaking.

As far as the exhaust method. I think it would work if you were not running a muffler. The dyno shop i go to has a grand national. They said that with a muffler on the exhaust it created to much pressure in the exhaust in combination with the turbo slowing down the exhaust gas(which would reduce the Bernoulli's affect) to work. In fact they said that with a muffler it actually would blow exhaust into the crankcase.

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

Exhaust vacuum is measured by a lot of enthusiasts not just hondas. Back pressure is not just restriction like you are leading everyone to believe. Backpressure is created as a function of restriction , gas temperature and exhaust pulses (which are most often misinterpreted as restriction). Velocity is a function of gas pressure, temperature, humidity and many other less influential factors. Any motorcycle engineer will give you the exact explanation and calculations, me i dont care to nor can I. If you dont believe me, I really dont give a rats ass.

This is one reason Harley's have a power cone that is installed inside the entry of the pipes at the head. The cove formes a step that disrupts the reverb of the exhaust pulse limiting the collision of gasses leaving the head and pulse comming back. In some application this in necassary.

Excessive velocity will lead to poor engine performance as well. More is not always better. Read up on the scavenging effect of exhausts/head flow.

Never said exhaust vacuum wasnt measured by anyone except Honda owners -- said in the case of crankcase exhaust evac setups I havent run across any actual measured numbers except from the honda crowd.

The thread and topic was about crankcase evac, not exhaust design. Besides, we have a big blockage hanging off the end of our manifold (this is the turbo forum, right? *doublechecks*), that kinda kills exhaust pulses post-turbo, no?

The question was that a muffler creates to much backpressure and it overcomes the Bernoulli's effect -- my post was intended to point out that the people who say this are old school v8 owners who run large, chambered mufflers. The turbo import owners who run straight-through mufflers have proven that the exhaust evac setups do work with this type of muffler, and have measured the vacuum to prove it, in both hondas and high hp single turbo supras.

Youre smarter than I am though, any input on the exhaust evac setups as a means of reducing or eliminating crankcase pressure? Short of a vacuum pump, Ive been led to believe it is the best method, especially on a turbo car where you have to still have a means of adding vacuum to the crankcase and boost keeps you from using the intake as a source...

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

I havent read info saying a chambered muffler system cant be used. In fact most of the old school v-8 guys were the originators for testing exhaust back pressure to properly design a system so that you could.

you right that our mufflers do make it easier due to the fact that we use a straight through design.

If your looking for a evac setup where you use vacuum from the exhaust there are a lot of designs on the internet. Its a very old concept just most people either dont trust it, arent aware of it, or dont want to go through the hassel of it. Its easy to plumb it into your intake!

http://www.sdparts.com/product/MOR25900/MorosoCrankcaseEvacuationSystem.aspx

Thats the type of setup your looking at, now granted you dont need all that equipment since we dont have a v-8. If you read more about it, you need to be careful (mostly when using vac pumps) because too much vacuum is more harmful than good.


Personally i would measure the vacuum created at different rpm and load points. Place a dimple into the pipe right upstream from the point you want to tap into to create a venturi effect. Measure your vacuum and note it. Next thing is you will need to build a catch can setup and install it in the conventional manner except the vac source will be the exhaust. You will need check valves so that the exhaust doesnt push back into the catch can. After that your going to need to tap into the motor in some way to monitor crankcase pressure to see how well you evac system is working. There is no basic design that works on all 4 cylinders or all motors. Each system needs tobe taylored to each setup.

Moroso techlines actually suggest not to run the setup on a muffler car, which is where a lot of the v8 forums are getting info from, which then of course turns into they dont work on muffler cars period thanks to the usual generalization that comes from internet car forums.

I actually already linked to the moroso, mr.gasket and summit kits earlier in the thread, but thanks



My issue with running a crankcase evac setup into the intake is that pre-turbo, very little if any vacuum is actually generated, unless you run a restrictive intake. If you just run a filter on the turbo inlet, or no filter at all, you have nearly no vacuum generated.

With the HX40, I have very little room to run a 4" intake pipe, its going to be tough to even run a cone filter, which led me to the exhaust evac setups.

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

dude, the intake mani is supposed to suck air from the engine then the engine gets fresh clean air from the intake pipe. the intake pipe don't suck from the engine. i've been planning an exhaust evac w/catch tank setup but i got caught up in the ms. so when i do it i'll post results.

got that megasquirt!

See it all depends on the muffler setup. some mufflers offer no restriction like you pointed out however straight through are not the only design.

Who am I to challenge everything I see written on the net (especially that aseclub.net thread), but it seems as if everyone jumps on the same train without actually thinking through what is going on here.

For one thing, think about why there are two ports on the valve cover. When the throttle plate is closed, there is a high vacuum in the intake mani, and gas is sucked from the valve cover into the intake mani. This removes the corrosive gases that are trapped in the engine. But you still have these corrosive gases in the crankcase unless you have a total vacuum (e.g., like a 2gnt on the moon.) Oh oh, problem. Now let's introduce the 2nd port into the equation.

The 2nd port brings in air from after the air filter and before the throttle plate. When the throttle plate is closed, vacuum is created through the 1st port that is connected to the intake manifold. This creates a vacuum inside the valve cover, which creates suction through the 2nd port, bringing in FRESH AIR. Aha, now we have a real way to remove the corrosive gases in the crankcase. Fresh air dilutes the corrosive gases in the engine. Whereas a vacuum reduces the pressure, as soon as the vacuum ceases to exist, you still have these gases remaining in the crank, contaminating your oil.

So these methods of having BOTH ports go to vacuum with NO fresh air being introduced to the crank makes very LITTLE sense to me. But yay racecars do it, and if I see a single thread where a bunch of 2jz's do it then it must be mandatory...dumping oil straight into the exhaust, hey its okay there are technosophisticated things happening like Bernoulli's effect and magical rice pixies and who cares it's METAL. If you don't understand what is going on, add a check valve in a random location. Problem fixed.

Now look at this picture:

Wow that's awesome trendy font. And it's on the net. Let's use it! But wait a second, what new force is pushing oil out the 1st port and into the intake manifold, requiring a catch can? Remember vacuum pulls gases into the intake mani through that port on a NT with the throttle plate closed. We didn't need a catch can in that location then. Why do we need it there now that we have a turbo? Do we believe that during boost, that the crankcase pressure is greater than the pressure that is being created by your turbo, and air flows from the valve cover to the intake mani under boost? um well...

Yes sure the crankcase pressure is going to be higher under boost than it will be NT as you get more blowby past the rings, but if *you* were gas and had the choice of going through the 1st port through the PCV into a high pressure intake manifold, or through the 2nd valve cover port through a filter and straight to the atmosphere, which route do you choose? The answer is port number two. This is where oil will be blown out under pressure, and where a catch can should be.

Hey but what do I know I'm not even turbo. Please let me know what I'm doing wrong.

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO

The stock setup works just fine, if you are stock (if you ignore the fact that the stock pcv doesnt keep oil from being sucked into the intake manifold).

When the pcv valve closes on a stock car, what you are calling the inlet is actually an outlet. The vacuum generated in the intake tube pulls those crankcase gases out of the valve cover and into the intake. There is no fresh air being drawn in during this time. Fresh air being drawn in during idle is a side effect of how the system is plumbed, not the goal.

It is not a one way system. At idle and decel, fresh air is drawn in, but as soon as the pcv valve closes (accel), crankcase pressure and blow-by is pulled into the intake via your "inlet". In this way, crankcase pressure is being relieved at all times on a stock car.



This is the turbo forum though. The stock pcv doesnt work under boost. The stock pcv works during periods of vacuum: idle and decel.

What happens when your not in high vacuum? Crankcase pressure is still generated, and that pressure is going to build until it finds a release. Sometimes its through the dipstick tube. Sometimes its through your main seals.

The goal then is to reroute the pcv to avoid boosting the crankcase, but still having a means of pulling blow-by and crankcase pressure at all times, both idle and under accel. One method is to reroute the "inlet" port preturbo -- depending on the setup though, very little to no vacuum is actually generated though. If you run an open turbo, or just a filter on the turbo, this is essentially no better than just venting that port to the atmosphere.

Another method is to run a vacuum pump. This is costly and unless you run a 350 in your eclipse, your probably not going to find a bolt-on kit. Some people use electric smog pumps, but they dont usually live long when run constantly.

Another method is the exhaust evac setup. Im choosing this because its the only means other than a vacuum pump that completely isolates the intake tract from oil and contamination and still generates vacuum in the crankcase. I will be running sealed catchs inline to avoid just dumping blow-by in the exhuast as well.

95 Avenger
ATX->MTX Swap
Holset HX40 @ 26 psi

well, thanks for the obvious EZ.

For a simple setup what i run is a catchcan that has two independant chambers. One that goes between the PCV and Valvecover (My PCV Seals fine under boost) and the second chamber is plumbed to the other port on the VC and it does have a small filter.

If you just put a filter on that nipple, it can blow oil out onto your motor.

Now what Ryan and I are discussing is finding a way to use vacuum created by the exhaust instead of the intake vacuum used. Oil in the intake does not increase HP. So try to stick with us here. The delimma is that most mufflers do not allow exhaust to flow fast enough to create a vacuum. V-8 guys argue no muffler does which is not altogether true especially with a straight through design like ours. ryan has posted the pertinant details so I am not going to repeat them.

Terry

Custom can i made.

why would i sit in my closet? lets be adult about this. there is no vac. in the intake tube. the vac. is created after the tb. any draft from the intake tube would be insuficient due to the pressure in the vc while under boost. hence the need for a real evac system.

got that megasquirt!