Too much pressure in crankcase, why?
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Joined: Jun 2002
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I dont know how you checked your PCV, if you just saw it sealing by just blowing in to it then try to clean the PCV valve with some brake/carb cleaner or get a new one. Because their is no way you can blow 15-20psi at it with your mouth. It should rattle, but that still doesnt mean its okay.
Personally, I would get a catch can and use both ports and route them their. and block the port on the intake manifold were the pcv should go. Should solve your problem.
Personally, I would get a catch can and use both ports and route them their. and block the port on the intake manifold were the pcv should go. Should solve your problem.
PCV Valve is only supposed to work under vacuum.. when there's positive pressure the check ball is kept closed.. However, if its leaking/stuck, it could pressurize the crankcase so its probably a good idea to check it anyway.
Originally Posted by sloweclipse
I dont know how you checked your PCV, if you just saw it sealing by just blowing in to it then try to clean the PCV valve with some brake/carb cleaner or get a new one. Because their is no way you can blow 15-20psi at it with your mouth. It should rattle, but that still doesnt mean its okay.
Personally, I would get a catch can and use both ports and route them their. and block the port on the intake manifold were the pcv should go. Should solve your problem.
Personally, I would get a catch can and use both ports and route them their. and block the port on the intake manifold were the pcv should go. Should solve your problem.
manual. They suggest pulling out the PCV from the elbow that connects to the valve cover and see if there's vaccum with the engine idling. Also they suggest listening to hear it rattle as well as checking the return spring pressure with a small rod or wire. All those tests were performed and the results point to a proper functioning PCV valve.........
Originally Posted by MalibuJack
PCV Valve is only supposed to work under vacuum.. when there's positive pressure the check ball is kept closed.. However, if its leaking/stuck, it could pressurize the crankcase so its probably a good idea to check it anyway.
Originally Posted by 93h22cvc
welcome to the world of mitsubishi
issue? I'd heard that Shiv sees this phenomenom extremely seldom and he dynos about 5 EVOs a week (or is it 5 EVOs a day?)
Originally Posted by 93h22cvc
hmmmshiv is god how could i forget. i personally have had 4 1st gens all modded under high boost levels this is common genious.
I decided to start this topic exactly to get this kind of information...... I appreciate the information. I mentioned Shiv's opinion because he does have some experience with EVOs. Obviously his experience differs from other folks... I don't know why his experience is differnt but I'll take it at face value.... I guess the bottom line is that this is a common occurrence in some people's experience but very rare in Shiv's experience 
Since I'm not Shiv, this might be somewhat normal for my car
Last edited by silverEVO8; Jul 6, 2004 at 12:07 PM. Reason: typo
welcome to the world of mitsubishi
Originally Posted by 93h22cvc
i personally have had 4 1st gens all modded under high boost levels this is common genious.
Shiv has seen the dipstick pop out one time with an Evo on his dyno. That was my car. It only happened one time ever and never reoccurred. It happened under the following conditions:
1. My oil was overfilled. My dipstick indicated about a 1/16" over the top fill line.
2. I was using a homemade oil catch system made by Mitsuorder. It does not recirculate, which could result in a slight pressure imbalance. I find it VERY telling that Mitsuorder chimed in to say that this has happened to him as well. I don't think it is a coincidence. I have since removed that simple oil catch system.
3. My car was being tortured on a dyno. I think it was MalibuJack that hypothesized that under wide open throttle, the engine's oil pickups and gallies would be designed to "expect" forward thrust of acceleration, which is not present on a dyno. This could also contribute to my problem.
4. As many others can attest, the 4g63 is prone to popping dipsticks. So if the conditions are right (like they were in my case) it can happen when nothing at all is wrong with your motor.
Finally, I have road raced once (about 30 laps around Streets of Willow) and drag raced tons of times since this has happened and it has never reoccured. I personally think the overfill on oil was the number one culprit. Since then, I keep my oil level at the LOWER fill line.
1. My oil was overfilled. My dipstick indicated about a 1/16" over the top fill line.
2. I was using a homemade oil catch system made by Mitsuorder. It does not recirculate, which could result in a slight pressure imbalance. I find it VERY telling that Mitsuorder chimed in to say that this has happened to him as well. I don't think it is a coincidence. I have since removed that simple oil catch system.
3. My car was being tortured on a dyno. I think it was MalibuJack that hypothesized that under wide open throttle, the engine's oil pickups and gallies would be designed to "expect" forward thrust of acceleration, which is not present on a dyno. This could also contribute to my problem.
4. As many others can attest, the 4g63 is prone to popping dipsticks. So if the conditions are right (like they were in my case) it can happen when nothing at all is wrong with your motor.
Finally, I have road raced once (about 30 laps around Streets of Willow) and drag raced tons of times since this has happened and it has never reoccured. I personally think the overfill on oil was the number one culprit. Since then, I keep my oil level at the LOWER fill line.
Last edited by Smogrunner; Jul 6, 2004 at 11:19 AM.
This happened to me with my oil being slightly overfilled and with me punching the go pedal while on the highway with the a/c on. Sorry that my oil catch contributed to your problems Smogrunner. What type of oil catch are you running now? I'm going to go the route that MalibuJack posted.
Originally Posted by MalibuJack
I have heard that this is a pretty common phenomenon on the 4G63T... If you haven't already done this, try putting a breather on the valvecover in place of the breather hose..
This is actually something that used to happen pretty frequently on my supercharged small block..
There is likely nothing wrong, what happens at high RPM is your engine builds up pressure from all the moving parts, plus the engine blowby.. what happens at high-rpm heavy load is there's more air trying to get out, than the breather hose can handle.. Its likely the hose itself is building up a bit of crud in it.. so the air will take the path of least restriction, which will be the next leakiest part of the engine, or the dipstick tube..
Put a catch can on the breather to catch the oil, and vent the catch can to the atmosphere (put a little filter on it since it also breaths in under part throttle when the engine is under vacuum and the PCV system is functioning) your problem should go away, just remember to use large enough hose and not kink it..
You can check your blowby and compression, and you could have a problem, but its unlikely.. once you start dealing with higher boost, higher RPM, and higher cylinder pressures you begin to see these phenomenon..
This is actually something that used to happen pretty frequently on my supercharged small block..
There is likely nothing wrong, what happens at high RPM is your engine builds up pressure from all the moving parts, plus the engine blowby.. what happens at high-rpm heavy load is there's more air trying to get out, than the breather hose can handle.. Its likely the hose itself is building up a bit of crud in it.. so the air will take the path of least restriction, which will be the next leakiest part of the engine, or the dipstick tube..
Put a catch can on the breather to catch the oil, and vent the catch can to the atmosphere (put a little filter on it since it also breaths in under part throttle when the engine is under vacuum and the PCV system is functioning) your problem should go away, just remember to use large enough hose and not kink it..
You can check your blowby and compression, and you could have a problem, but its unlikely.. once you start dealing with higher boost, higher RPM, and higher cylinder pressures you begin to see these phenomenon..
Nice! Do you have a picture of the setup. Would appreciate it if you can share.
Thks
Any car I've ever taken to the mitsu dealer for service comes 1/4 qt over filled. I know TOO much oil can be really bad for your engine, but after talking to some guys who race quite a bit, they said it was a common practice for various reasons to slightly overfill.
Hell if I know, overfilling by 1/4 qt has never hurt any car I have owned.
Hell if I know, overfilling by 1/4 qt has never hurt any car I have owned.
Last edited by leonard_shelby; Jul 6, 2004 at 01:39 PM.
I slightly overfill, have been on Shiv's dyno, Willow Springs, Buttonwillow, and ruitinely redline it with my catch can setup. Never had a problem and my intake tract is very clean without a trace of oil. Warning for the ghetto phobic.... https://www.evolutionm.net/forums/sh...ighlight=catch
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