Dipstick popping out questions

[Deadly BlaZe]

Me and my friend are having a friendly argument whether or not a dip stick popping out is normal or not. The conditions are driving it hard up to at least 6k rpms while hitting full boost of around 18 psi and with a good dipstick. I've linked my friend to threads discussing this, but he is not convinced that it is NOT normal for a dipstick to pop up under heavy loads. So the question is, under those conditions, is it normal for a dipstick to pop up and spray oil under the engine bay?

 

[turbodsm_125]

it is very normal for a dsm to blow the dip stick out and spray oil every where! it looks like you blew the engine up to the untrained eye! But with good compression and high boost levels it happens all the time as any serious dsmer knows it is a fact of life. take vise grips and pinch the top of the tube and it will stop this from happening, but this is one of many options to fixing this, there are whole threads devoted to just this subject matter

 

[Deadly BlaZe]

But with good compression and high boost levels it happens all the time as any serious dsmer knows it is a fact of life. take vise grips and pinch the top of the tube and it will stop this from happening, but this is one of many options to fixing this, there are whole threads devoted to just this subject matter

If it's normal, how do you explain the fact that my car never does it? I think on a well-running motor it SHOULDN'T blow the dipstick out no matter how much boost you're running. Btw yes I know this has been discussed plenty of times, he is not convinced though since no one gave a concrete answer. I'm trying to convince him that if he DOES avoid fixing the problem by pinching the tube shut, it will just cause him problems in the future. I'm looking for a real explanation, not a "Oh it's normal and you need to accept the fact that dsm's do this" cause that's just a silly, uneducated excuse.

 

[Locke]

The dipstick pops out because the crankcase pressure is raising faster than it can be evacuated. Excessive blow-by, or perhaps a clogged or misconfigured breather setup, is the reason for this.

 

[zatomz]

It's normal for a car with bad crankcase pressure but sure as hell hasn't happened to be in my 3 years of dsm driving. Can I say hell in the forums??

 

[kenamond]

To elaborate on what Locke said (which I agree completely with)...

You shouldn't be popping your dipstick. My guess is that your friend has tinkered with his breather setup and/or has a bad PCV valve and/or has excessive blowby and/or has leaking intake valve stem seals.

The VC breather has two modes:

Vaccuum: When the IM is under vaccuum, the PCV valve opens and lets a certain amount of air through its restriction. The air has to come from somewhere. Some of it comes from blowby. The rest comes from the breather line on the side of the VC. If you have bad compression, I imagine that in this case, the blowby might overwhelm the PCV valve and the rest will go out the breather. When the PCV valve is open and letting air from under the VC get sucked into the IM, it is ventilating the crankcase. The air/fuel mix that blows by the rings during the compression stroke will contaminate the oil if the fumes aren't removed, so that's why the ventilation is there. The "V" in PCV is "ventilation" after all.

Boost: When the IM pressure is greater than the crankcase pressure, the PCV valve is supposed to close. This happens under boost. In this situation, all blowby, leaking PCV air, and intake valve stem seal leaks have one place to go out, and that's the VC breather.

The dipstick pops out when the crankcase pressure is too high. This means that either your PCV valve isn't closing or your intake valve stem seals are leaking and you're boosting your crankcase as a result, or there is so much blowby that it's overwhelming your VC breather line.

I've heard of high performance motors overwhelming the VC breather just due to blowby from very high compression ratios (rediculous boost) even with good compression, and folks have to consider a vaccuum pump, adding additional breather flow (add additional breather passages, etc.) or something else above-and-beyond to compensate in those cases, but I doubt 18psi (or whatever your friend is running) would qualify.

 

[TerribleTSi]

my car NEVER blew the dip stick up either until i blew a head gasket. after i replaced the HG it has never happened again.
excessive crank case pressure blows the dip stick up....period, although there are many different reasons it happens you are correct, it is not necessarily normal for a mostly stock DSM to do that is in perfect working order. but most kids with 1g have 1**,*** miles on their motors. people need to realize that 160,000 miles doesn't make a "race car"

 

[tqmx1]

Try swapping dipsticks and see if the popping out follows the stick or stays with the car. The dipstick seal is made of a rubberzied plastic over the years they harden and shrink and no longer make a good seal to the tube.

So if it follows the stick I would say your buddy is dew for a new stick or crimp the end of the tube.

 

[No_Skillz]

Try swapping dipsticks and see if the popping out follows the stick or stays with the car. The dipstick seal is made of a rubberzied plastic over the years they harden and shrink and no longer make a good seal to the tube.

So if it follows the stick I would say your buddy is dew for a new stick or crimp the end of the tube.

Just the opposite is true. If you have a bad seal you have less of a chance of popping out the dipstick. Besides... you never want to crimp the dipstick tube or use any other manner of forcing the dipstick to stay in because it's just a bandaid to the problems that kenamod just described. Bad PCV, bad valve seals, bad breather, bad headgasket, or bad rings.

 

[UKNOWHO]

extremepsi.com sells brand new dipsticks with new rubber gromet for 20 bucks i believe. and autozone def. stocks the pcv valve for 6 bucks

 

[Deadly BlaZe]

Thanks for all the great replies guys. This should convince him.

 

[tqmx1]

If you have a bad seal you have less of a chance of popping out the dipstick.

How the heck do you come up with that? If the engine is for the most part good (normal leakage) thats between 5to8% past the rings the normal breather and PVC system can handle it. Now if you have a bad (loose) dipstick seal the air that is leaking past the rings is always looking for a easy way out be it PCV, breather line and now it has a third loose dipstick. Also under boost it gets worse the PVC is closed down tight and now all that pressure and there is a whole lot more of it has to try and leave through the breather tube (less than 3/8") you bet it will lift a bad dipstick right out of the housing.

Thats why I first told them to swap sticks to see if it stayed with the engine or followed the stick to see if it was a sick engine or just a bad stick.

 

[DIS1KRAZY]

Is it hard to change a pcv

 

[420a-t]

Nope. Make sure you don't get a replacement pcv valve from anywhere like autozone, napa or checkers though. Get an oem one from the dealer or go to usplastics.com and order one of their check valves.

 

[kenamond]

Is it hard to change a pcv

As 420a-t said, it's simple, but you have to make sure you get the correct PCV valve (Autozone, Carquest, etc. will not work for boosted applications like ours).

If you read my post above, the PCV has two jobs: 1) It's a metered orifice when the IM is under vaccuum, and it lets a specific amount of air in under these situations, and the amount increases with increased vaccuum. 2) It closes when the IM pressure exceeds the crankcase pressure.

When the PCV valve fails, it's usually that it's just not sealing (#2 above isn't happening), and this causes you to boost your crankcase.

The check valve that 420a-t was talking about lets you set up your PCV system so that the PCV valve only has to do #1, while the check valve does #2. But for this to work well, you need to keep crap from getting into the check valve.

There's a long thread about this posted originally by FORMONTOYA called "Stupid PCV question" that you should read to find out all about the setup options. Read it to the end; some folks make suggestions in the middle that are wrong. You should get a good sense of what a PCV system is supposed to do, and then you'll understand what a correct setup entails.

 

[brute]

I strongly disagree with crimping the dipstick tube. The pressure should not be so great in the crankcase, and if anything, I'd rather it pop the dipstick to get rid of it before it caused major damage. Don't get it twisted: when you crimp the dipstick or zip tie it down, you aren't fixing the problem. Instead of doing 'bandage fixes,' just go straight to the route. Get a new dipstick, PCV, and check valve -- that's like $30 total, and it takes no time at all. Problem solved.

 

[GS-T_Newboost]

my old setup i would blow oil all over the engine bay through the vc breather. turns out i to much boost on a stock 420a = broken ring lands on the pistons. this happened twice in a 1 month period. this caused excuess crankpressur. to solve this put a set of total seal rings that helps prevent crankpressur

 

[tqmx1]

Ok I will recend the crimping the tube statement. But if the dipstick is loose by all means replace it. Oil + hot manfold = smoke or at the worst FIRE

I think on this subject we are

 

[Deadly BlaZe]

I think on this subject we are

Yeah I think these replies are enough. I've been trying to convince my friend that clamping the dipstick tube shut can only give him more problems in the future rather than just keeping his engine bay clean. I've pinched my dipstick tube shut before and pat my self on the back, little did I know is that about 5,000 miles later, the motor blew. Obviously the motor had it's own problems besides that, but i'm sure by clamping the dipstick tube shut, it just speeded up the process (the day the motor blew, the dipstick popped out...even with the tube shut, you can just imagine how bad that must be). Mods can lock this thread since there have plenty of good answers and explanations posted.

 

[No_Skillz]

How the heck do you come up with that? If the engine is for the most part good (normal leakage) thats between 5to8% past the rings the normal breather and PVC system can handle it. Now if you have a bad (loose) dipstick seal the air that is leaking past the rings is always looking for a easy way out be it PCV, breather line and now it has a third loose dipstick. Also under boost it gets worse the PVC is closed down tight and now all that pressure and there is a whole lot more of it has to try and leave through the breather tube (less than 3/8") you bet it will lift a bad dipstick right out of the housing.

Thats why I first told them to swap sticks to see if it stayed with the engine or followed the stick to see if it was a sick engine or just a bad stick.

Simple physics. If there is a leak in the dipstick seal, it will let air out and therefore have less pressure on it. If it seals well, then there will be more pressure pushing on it, popping out. In a real world scenario it really doesn't matter... the threshold between a bad seal letting pressure out or popping the entire dipstick out is probably so small that it's pointless to debate. What I'm simply trying to say is that switching a good dipstick in will not help it stay in.

 

[wret]

Me and my friend are having a friendly argument whether or not a dip stick popping out is normal or not. The conditions are driving it hard up to at least 6k rpms while hitting full boost of around 18 psi and with a good dipstick. I've linked my friend to threads discussing this, but he is not convinced that it is NOT normal for a dipstick to pop up under heavy loads. So the question is, under those conditions, is it normal for a dipstick to pop up and spray oil under the engine bay?

It's common enough to be listed in the FAQ's.

http://www.dsmtuners.com/forums/fre...tions/273784-why-my-dipstick-popping-out.html