How to fix your oil cap from leaking [Merged 3-8] leak leaky

[underdogTSI]

OK, my oil cap seems to leak, and when I take it off with the motor running, it shoots alot of air out, I also had that dip stick problem where it always pops out. I have bent the dip stick tube enough to keep it in there and put in a new pvc but nothing has stopped this...Anybody have this problem or solution?? Thanks.

 

[rEclipserGST]

If the PCV valve vents crank pressure right? If the PCV valve is leaking out of the box... does that not mean it is venting pressure constantly? Or does it work some other way that I do not understand? Explain in detail please. I too have oil leaking, and I have two seals around my oem cap... its a TIGHT seal but does not stop the oil unfortunately.

 

[steve]

The PCV valve is intended to vent crankcase pressure and vapor into the intake manifold when the pressure in the crankcase exceeds the pressure in the intake manifold.

On a non-turbo car that happens most of the time since the intake manifold is in vacuum and the crankcase is at atmospheric pressure or slightly higher due to blowby.

On a turbo car not only does the valve have to function like this, but it has to block any flow from the intake manifold to the crankcase which might happen under boost. If it doesn't seal 100% then you have the turbo pressurizing the crankcase and that pressure looking for a way out, the easy ways are the breather, dipstick, and oil cap. Even if the valve does seal 100%, boost causes higher blowby from the rings and because the route to the intake is blocked by the valve being closed the pressure has to find a way out. Making that much crankcase pressure under boost to blow out the dipstick or oil cap gasket when it's not leaking past the PCV is signs of bigger problems.

 

[Dsmj89]

I strongly agree with steve. A new oil cap is and should perform without a problem.
There is no need to invent and put gasket sealent on it, that is just asking for trouble down the road.
Keep it simple and make sure your oil ventilation are functioning the way they are supposed to as stated above.

 

[TSIGuy510]

could leaking oil cause the car to run like crap, low idle and sputter under WOT. I noticed a large! puddle of oil in the bottom right corner of the valve cover. dipstick also pops out just a little sometimes. Also notice my car goes through oil very quickly, and sometimes a little greyish black smoke with its sputtering. my friend thinks i have a bad turbo oil seal any ideas of what the problem is?

 

[KKneipper]

is your car leaking oil anywhere other than the oil cap? or is it just burning oil? if it is just burning it, then that would explain the smoke. if its leaking oil, the smoke could be caused by any number of things. check your coolant to see if you have any oil in it, and vice versa.

 

[icemanracing]

what would happen it i put a vaccum pump on my car to relieve the crankcase pressure. Oh yeah my system is not stock running 35psi and i have a breather/catch can already installed. My compression is great and no leaks other than a shitty dipstick tube that shoots out under hard driving. Can i run a vaccum pump on a boosted car?

 

[anchew02]

ive been dealing with the same issue and found my valve cover had a hairline crack in between the to lower bolt holes at the cam tower,pulled it off and epoxied it nicly cleaned it up and that fixed my major oil issue, now i found oil cap dribbling into the same area but i can deal with that much.

 

[clizz3]

ive gotten a new cap and the valve cover doesnt have a crack. it only leaks under boost.

 

[mattasi]

USE TWO SEALS UNDER THE OIL CAP, WORKS PERFECT! Sorry tired of saying it. 2nd time today haha..

 

[clizz3]

USE TWO SEALS UNDER THE OIL CAP, WORKS PERFECT! Sorry tired of saying it. 2nd time today haha..

my bad dude. ill give this a try

 

[mattasi]

my bad dude. ill give this a try

it's cool man.

 

[red_devil]

USE TWO SEALS UNDER THE OIL CAP, WORKS PERFECT! Sorry tired of saying it. 2nd time today haha..

Again this has been stated more than twice. The oil cap seal is not the problem. Its excessive crank case pressure.

 

[92gsxbafaro]

OK, my oil cap seems to leak, and when I take it off with the motor running, it shoots alot of air out, I also had that dip stick problem where it always pops out. I have bent the dip stick tube enough to keep it in there and put in a new pvc but nothing has stopped this...Anybody have this problem or solution?? Thanks.

what i did when i bought a new cap and it still leaked was take the rubber gasket from the old one and added it to the new one its a super tight fit and doesnt leak anymore. just make sure the old gasket has some life in it still

 

[cleanoe2g]

Spray your valve cover down real well with brake parts cleaner and check for hairline cracks and broken plug wire cover bolt holes on the vc. Mine were hollowed out, creating an oil fountain spraying oil onto the underside of my hood. I just semi-scanned over your post, so sorry if this is repeating someone else. I didn't see it mentioned.

 

[mattasi]

Again this has been stated more than twice. The oil cap seal is not the problem. Its excessive crank case pressure.

The thread I responded to got merged with this one or something. Anyways I was saying to just use two gaskets. And if it still leaks or dipstick is popping out then reduce crankcase pressure.

 

[obsidian]

Again this has been stated more than twice. The oil cap seal is not the problem. Its excessive crank case pressure.

I'm not saying excessive crank pressure isn't an issue here, but the seals get bad. I also had to use two seals and it worked like a champ.

I'm saying it's physically impossible for me to have excessive crankcase pressure to blow oil out of MY cap.

Why?

Because I have an open atomospheric filter venting any pressure in my crankcase. It is much easier for any pressure to vent through my open filter than it is for it to blow past a seal.

Two seals worked for me. I'm running a good crankcase ventilation so no pressure can build up on the top end.

My seal was bad. A new single seal would not work due to the valve cover possibly being worn out on the bottom (have yet to see that mentioned, where does the cap tighten down? On the aluminum soft metal valve cover) or the cap's securing tangs (true word) are worn and not causing a proper seal. Adding or getting a thicker gasket would reinforce the metal difference and cause a better seal.

 

[red_devil]

I agree that if your oil cap seal is bad then yes you will get some oil on your valve cover. But a good working oil cap and a good seal should be all thats needed.

 

[cleanoe2g]

The reason I say this is because I replaced what I thought was another bad oil cap and it wasn't. I was squirting oil from my crappy vc.

 

[mattasi]

I'm not saying excessive crank pressure isn't an issue here, but the seals get bad. I also had to use two seals and it worked like a champ.

I'm saying it's physically impossible for me to have excessive crankcase pressure to blow oil out of MY cap.

Why?

Because I have an open atomospheric filter venting any pressure in my crankcase. It is much easier for any pressure to vent through my open filter than it is for it to blow past a seal.

Two seals worked for me. I'm running a good crankcase ventilation so no pressure can build up on the top end.

My seal was bad. A new single seal would not work due to the valve cover possibly being worn out on the bottom (have yet to see that mentioned, where does the cap tighten down? On the aluminum soft metal valve cover) or the cap's securing tangs (true word) are worn and not causing a proper seal. Adding or getting a thicker gasket would reinforce the metal difference and cause a better seal.

Glad I am not the only one that feels this way

 

[obsidian]

Red Devil, me and you are saying the same thing, in different ways.

1. The valve cover is made of aluminum which is a soft metal. The constant on/off of the steel tangs of the oil fill cap will easily remove the aluminum over time which will reduce the pressure and over time, reduce the effectiveness of even a brand new seal.
2. The steel tangs due to heated over and over and over and used over and over and over will wear them out as well and they will lose their tightness, so to say.
3. My statement is ONLY TRUE to oil seeping from the oil fill cap. if you're blowing your dipstick out and squirting oil everywhere, well, that is an entirely different matter.

I have a feeling that this issue is only going to get worse as these engines and valve covers get more and more use.

 

[RT-AWD]

I have the oil coming out of my filler neck only. It gets about 2-3 cap fulls. I have removed my pcv valve, fiav and emissions equipment. I tried a cap off another car but no luck. My motor is pretty fresh (about 1500 miles on it) kelford 272 cams eagle/ross combo 25 psi on a 50-trim I also have a oil catch can. I'm going to try the multi-gasket method.. any other suggestions?

 

[Gearhead4G63]

I bought an HKS oil cap it stoped leaking from there, as far as my dipstick goes I didn't crimp it I put a bigger diameter o ring in it.

 

[jeber21]

get a new cap and fabricate a new dip tube

 

[RT-AWD]

My dipstick doesnt pop out. just oil out of the Valve Cover neck

 

[obsidian]

double gasket would probably be the easiest way.