4xforce

iTrader: (25)

I am using a 25 gallon shop compressor. I was half tempted to really crank it up to see if I could get enough air in but I figured that would not be in my best interest. By the way I tried plugging the valve cover to intake hose and the valve cover to intake manifold hose where the PCV is both individually and together. Both at the same time resulted in a rediculous amount of air escaping from the oil fill cap. The problem has to be pressure leaking past an open intake valve. I really can't think of anything else and the most frustrating part is that there are people here who said that they have never had to find TDC or bump the starter to find a point where they could pressurize the system. I guess I will just have to give it another shot and hopefully I will get lucky.

EvODavO

iTrader: (8)

I tried again today and here's what happened... hooked up the compressor and was only seeing 16 psi of boost. Found a small leak in the upper ic pipe and fixed that up no prob. after a few mins of letting the air compressor run the boost didnt go up. So i left the compressor on and started turning the crank untill I got to TDC. At TDC the boost did not go up at all. So I kept turning the crank inch by inch while I had a buddy keep an eye on the boost gauge. I was able to start building more boost untill I hit 21psi. kept turning the crank slowly and boost went back down to about 18psi. the whole time the same amount of air was coming out of the breather valve. Not shooting out but a stready stream of air. I would think If the intake and exhaust valves were closing at a certain point the air would stop leaking out the breather. I am totally stumped and frustrated at this point.

EvODavO

iTrader: (8)

You Guys having any luck or did yall give up?

EVO8emUp

iTrader: (30)

Remove your PCV valve and clean it with brake parts cleaner. Blow it out and test it again. Sometimes they get a little boogered up and the ball doesn't seal properly. If it still leaks, replace it. I just tested mine last night and the PCV sealed 100%.

EvODavO

iTrader: (8)

^ I tried that. Do you have any air at all coming out the vlave cover breather when you do a boost leak test?

EVO8emUp

iTrader: (30)

No. I tested mine at 20psi. no air out of the breather or oil cap.

09Mustang

Good thread, my evo is surging.. i need to find some leaks....... i think i'm just going to replace everyyything.

EvODavO

iTrader: (8)

I guess this thread = FAIL for now i'll just boost leak test my car up to 21 psi...

4xforce

iTrader: (25)

To be honest I just gave up. Maybe I will try cleaning or replacing the PCV.

Evoryder

iTrader: (55)

You guys are pressurizing your valve cover by plugging it up. DO NOt plug!

TDC. Don't worry about getting to TDC doesn't really matter during most tests.

Plug up your mbc where it normally connects to the pressure side. If not you'll be leaking air out your mbc or ebc at your base boost.

See link for visual aid. https://www.evolutionm.net/forums/8018340-post8.html

EvODavO

iTrader: (8)

I didn't plug anything except the mbc hose and i still have air coming out of the valve cover breather. Even tried the MAP crank breather check valves. still could get only 21 psi max

tscompusa2

iTrader: (22)

never plug the valve cover up. if you cant build 30psi or more quickly then you have a massive leak somewhere. it takes my car 3minutes to go from 30psi down to 0,
and 15 seconds to go from 0 to 30.

you cant build more then 21psi even with the mbc cranked up? time to find the air leak. Use soap and water in a spray bottle and go to work. Silicone rtv is your best friend also.

Evoryder

iTrader: (55)

Air is supposed to leak slowly out the valve cover. If it's pissing out your valve cover your check valve is shot. Take it off and physically inspect it. I replaced mine with a new valve.

4xforce

iTrader: (25)

Wanting to bump this thread to see if anybody has found any trick to solving the oil cap pressure leak issue? I purchased an aftermarket PCV but I was able to blow air through it both directions. The stock valve I took off sealed in one direction and the valve seemed clean and free moving so I kept it on. What type of check valve should I try if I go that route?

Evoryder

iTrader: (55)

Why not buy a new stock one.