Crankcase pressure

[DCEVING84]

I have a 84 mustang 5.0L and latley i have been getting excessive crankcase pressure. i am leakin lots of oil. it was leakin out of the PCV valve so i took that off and i put a breather on. it is now leakin out of the breather. it is also leaking out of the dipstick tube. somebody told me that i might have blow by. so i checked the compression and it was at 130-135psi. dont know what else to do. please help.

Thanks
Nick

 

[90mustangGT]

Do a leakdown test.

Don't disconnect the PCV, that will cause leaks. The PCV screen under there has been chaged too, right?

 

[DCEVING84]

What do u mean by the screen. are you talking about the baffel in the valve cover.I havent down a leakdown test. i am waiting on a guy so i can buy his set of trickflow heads.

 

[90mustangGT]

There should be a screen under the PCV valve, yeah way back there, often it's hard to get, but they get clogged and cause issues.

 

[DCEVING84]

Is it on the actual pcv or is it on the valve cover. i have crome valve covers

 

[dwhiskie]

The screen is under the PCV valve, You take the PCV valve out then the rubber gromet and then theres the screen.

 

[ninety15.0]

The PCV is in the lower intake manifold right behind the upper plenum..(in the middle). Is your car carburated? i dont know why you keep referring to the valve cover when your talkin about the PCV. Well if u are Fuel injected then u need to take the PCV out and then take the rubber grommet out and underneath there is a metal screen....its a crankcase filter. It catches the excess oil and often gets clogged up on highmile motors and causes problems like u are seeing. Replace this little 5 dollar screen and toss a new PCV in there and i bet your problems will be solved.

 

[DCEVING84]

yes my car is carburated. my pcv is in the drivers side valve cover

 

[90mustangGT]

I'm not that familiar with stock carb'd fords, but are you sure it's not the breather??? Does the line go from the valve cover to before or after the carb?

If it goes from the valve cover to before the carb, then it's a breather. If it goes from the valve cover to after the carb, (attaches to the intake manifold) then it's a PCV. Maby it doesn't have a screen.

On EFI vehicles, the PCV valve is on the back of the intake manifold, and has a screen behind it. Sorry for the confusion.

 

[8950HO]

I`m not 100% sure,but I don`t think an 84` carbureted car has the screen like the EFI cars have..

 

[vristang]

If there is no screen then there should be a baffle, regardless of how Ford built it. You are working on a modified engine, so your engines needs may be more demanding than the stock system can handle.

Out of curiousity, where is the inlet to the crankcase? I have not worked on many carb'd cars so I am not sure how this would normally be done.

If you are blowing the dipstick from the tube, I would suspect something other than a missing screen is the issue.

jason

 

[feifong]

too much pressure my car is the same way only leaks when i get on it. Worn Heads is my prob

 

[DCEVING84]

Thanks for all the help. i am just going to tear the motor apart and put trick flow pistos and rings on it.

 

[vristang]

Why rebuild a motor with good compression?

If the problem lies elsewhere (I think it does) then you will have the same problem when you get the fresh motor running.