crank case pressure question

Post by **T88lexus** » Wed Sep 01, 2004 9:39 pm

well reason why I asked this topic is because my ca18 blew the oil dipstick out of it tonight and almost cough on fire... hehehe.. was racing.. but luckly I notice something out of the hood right after I launched it and the dip stick came out of the tube...

well I know the fact that my engine is not a brand new engine or anything.. but usually when crank case pressure builted too much and blew the dipstick out like DSM poeples car due to the excess of blowby.. however, I do have a oil cacth can, and i checked it today after the oil dipstick came out.. and there was no oil at all.. I have been driving it for week and half now.. plus I boost the crap out of it.. I should of see some oil in there if there is a blowby.. I know nissan is pretty bad about the blowby. I know the fact because 2 of our sr20 did same thing and one cough on fire and burned them all... anyway.. what would you guys think of reason why it blow the dipsticks out..

compression tested 155psi all the way across.

Post by **r34 gtr** » Thu Sep 02, 2004 6:08 am

i know someone had the same problem as you a while back, i cant quite remember how it was resolved but maybe someone else can shed some light on it. to my knowlege it has only been covered once or twice so searching may be useless, but it couldnt hurt to give it a shot. i for one am puzzled, but ill let you know if i think of anything...

- tim

Post by **r34 gtr** » Thu Sep 02, 2004 6:20 am

oh, and be sure to check the pcv!

- tim

Post by **T88lexus** » Thu Sep 02, 2004 6:27 am

pcv is brand new ... i just put in there

Post by **r34 gtr** » Thu Sep 02, 2004 6:36 am

is it getting the correct voltage? mine wasnt but it still didnt cause that problem. still, ive heard it can be the culprit. there isnt anything blocking the breathers is there? i wouldnt think so, as you already checked the catch can but its always a possibility (though incredibly remote).

- tim

edit: heres the thread, it was ryan having the problems. http://www.nissaninfiniticlub....48622 - you might want to run a compression test if you havnt already.

Post by **T88lexus** » Thu Sep 02, 2004 7:14 am

what you mean by getting correct voltage? compression was tested 155psi all the way across in half way warm up

Post by **r34 gtr** » Thu Sep 02, 2004 10:28 am

you should be fine compression wise. take a meter and test the voltage going to the pcv to make sure its getting 12v. its entirely possible that it may only be getting some of that. mine was.

- tim

Post by **biosehnsucht** » Thu Sep 02, 2004 10:52 am

Dude, the PCV is a simple valve, what are you thinking of that needs voltage?

Post by **fanta** » Thu Sep 02, 2004 11:01 am

Crimp the dipstick tube where it contacts the rubber stopper a bit.

Post by **r34 gtr** » Thu Sep 02, 2004 11:14 am

uuuh, sorry. im a little burned out. i was thinking of the pressure control solenoid (i think?). i just suck without my car here for me to reference. ill let you know if i think of anything that would make sense to sane people.

- tim

Post by **T88lexus** » Thu Sep 02, 2004 7:52 pm

thank you for your help and all.. I appriciated your effort to help me and stuff..

I did crimped the tube with visecrip and bougth the spring from hardware store , and made it to where it has pressure on dipstick towards to the bottom. .. ...

Post by **float_6969** » Fri Sep 03, 2004 3:20 am

I was the one having problem with the dipstick. I was getting a lot of blow by and having to empty my catch can every week or so. Where did you put the catch can at? As for why, well my friend, the rings are probabally shot. That is the reason I'm rebuilding mine. Mine finally got so bad that I was blowing clouds of blue smoke on decel from high RPMS. it sucked. I still had good compression, but I'm sure that if I had done a leak down test, it wouldn't have come out well.

Post by **r34 gtr** » Fri Sep 03, 2004 5:15 am

mine didnt pass either the comp. test or the leakdown. head gasket was shot and the rings were bad.

good to know you got it fixed man, and sorry i was too incompetent last night to help you in any way. i promise i wont do it too often!

- tim

Post by **T88lexus** » Fri Sep 03, 2004 6:57 am

see the problem is I am not getting any blowby at all... I mean nothing.. I am pushing 10psi on sr t25 plus I drive hard.. my aftermarket oil cacth can is dry... and there is no oil in cacth can atall. however, I will test the leakdown sometime sooon to find out what .. but I didnt see dip stick come out on me last night after 2 hours of mountian drive ... so I guess I am ok for now..did compression tested after got warm and everything 161,160,160, 161. pretty good for 20 years old engine plus who knows howmany miles on it . I know the stock engine should pull between 171-142. but still . considering for 8.5-1 compression engine, which we have a couple of sr20 , it pulls 140s all the way across .. still runs well. anyway I am good to go I would say.

P.S what is FICD solenoid do? on the top of the AAC valve.. let me know

Post by **fanta** » Fri Sep 03, 2004 9:30 am

The rubber stopper may simply have deteriorated and was no longer able to seal properly.

Don't sweat it for now.

Post by **Bob_ea_ca18sx** » Wed Sep 08, 2004 8:57 am

make sure you don't have the pcv valve backwards. It sounds silly but it has to releive crankcase pressure. and if it is not then it will escape somewhere like dip stick. I.ve seen someone thread the dip stick hole and put a bolt in it and it blew oil out from around the oil filter. I had similar problem but mine smoked really bad because it was leak around the rings.

Post by **r34 gtr** » Wed Sep 08, 2004 11:41 am

wish i had thought of that... i feel dumb.

the manual says that there should be some pressure when you put your finger over the dipstick hole, so it was probably the stopper being shot. and if you didnt see it in the other thread, the FICD is a little thing that makes the car run a little higher when you turn on the air conditioning.

- tim

Post by **T88lexus** » Wed Sep 08, 2004 12:43 pm

thank you for the info.... however, the pcv valve is only one way to go on because one side has thread , other side doesnt.

but ya car seems to run ok.. so we will see.

Post by **r34 gtr** » Thu Sep 09, 2004 8:39 am

cool. keep us posted i guess.

- tim

Post by **NeedCAforS13** » Thu Sep 09, 2004 3:33 pm

since the seach button sucks *** now (I'm not lovin' this zero forum stuff) I can't find old threads of how to hook up a catch can. Can someone who has one hooked up please tell me which lines you put where:) (someone other than tim and his electric pcv valve that is)

Sean

Post by **RMiller** » Thu Sep 09, 2004 3:44 pm

http://turbovan.com/gallery/engines/1040418img.jpg

Check it out. The breather on the intake side t's with the exhaust side breather(or it looks like this anyway) and they both go to a catch can with a breather filter on it. This car is clean.

Post by **float_6969** » Thu Sep 09, 2004 6:07 pm

This is the stock setup...

Post by **float_6969** » Thu Sep 09, 2004 6:22 pm

This is the way I'm doing it. The only problem with this setup is that if you are getting a lot of blow by, you'll burn oil when you engine brake from high rpms...

Post by **float_6969** » Thu Sep 09, 2004 6:27 pm

With this option, you don't have to worry about burning blow by on decel, but during idle and decel engine braking the manifold has the greatest vaccum in the system. If it is great enough, it may cause the crankcase gasses to get sucked up past the rings and into the combustion chamber. I'm not sure of the validity of this idea and I've not tested it. The last time I had my car together I was using setup #1. When I put the motor back in, I'm going to use setup #2 and see what happens. Which do you guys think will work better?

Post by **Loofee95SE** » Thu Sep 09, 2004 6:37 pm

all the Aussie guys are using set-up # 1I don't know about u but tey do have some knowledge on this engine that we do, well exception of Dee and some other guys, I'm building #1 set up this weekend.

Post by **NeedCAforS13** » Fri Sep 10, 2004 10:29 am

with set up #2 you don't have a pcv valve... in that link the guy has a pcv valve on his catch can, which i think would work fine. but i do think you need to retain that pcv valve for things to function properly ryan...

Sean

Post by **Loofee95SE** » Sat Sep 11, 2004 2:11 pm

ok, so i just fitting my home made $30 catch can on my car. will post pics later tonight.

Post by **Trppen37** » Sat Sep 11, 2004 2:46 pm

what if you put a crankcase breather on it and let it vent and cover the intake side up?

Post by **nocwage** » Mon Sep 13, 2004 9:26 am

I don't think you should have to keep the PCV in the system, otherwise why does the one side have it and the other doesn't?It's just to protect the system from what's going on in the intake manifold, if you just had a straight pipe you'd have all kinds of wonderful combustibles going into places it shouldn't.

BUT I'm not a mechanic, this is just how it looks to me.

Post by **niscort** » Tue Sep 14, 2004 12:50 am

The perfect setup would use two seperate catch cans... As there are two different cycles in drawing the crap out of the engine. Firstly when the intake manifold is in vaccum, air is pulled from the intake after the afm 'through' the engine and past the pvc valve to enter combustion.. Secondly when boost is produced, the pvc valve shuts and air is drawn out of the engine into the system prior to the turbo.

option one is fine in boost situations, but as soon as your off boost any vapour will be pulled past the pcv with out drawing the oil out of the vapour.

option two works fine also in boost situations, but does nothing off boost as you are no longer sucking air through(in the ex valve cover, into the block, out the in valve cover) the engine to clean it out.

thoughts?

crank case pressure question

crank case pressure question

Re: (r34 gtr)

Re: (r34 gtr)

Re: (r34 gtr)

Re: (r34 gtr)

Re: (float_6969)

Re: (T88lexus)

Re: (r34 gtr)

Re: (NeedCAforS13)

Re: (NeedCAforS13)

Re: (float_6969)

Re: (float_6969)

Re: (NeedCAforS13)

Re: (nocwage)

Nissan Forums

Infiniti Forums

Datsun Forums

Technical Forums

Classifieds / Marketplace

Nissan Motorsports

General Forums