Pcv Screen

With that much oil in the catch can I would check to see if the screen is even there, also there should be a baffle attached to the lower intake under the screen, that could be missing.
If all that checks out next would be to do a leak down and compression test to see how valve seals and rings are.

Here' some help in the how to dept...

Google and YouTube are your friends in the how to department for general stuff.
See https://www.google.com/search?sourc...i22i30k1j33i22i29i30k1j33i160k1.0.Sv_YC3IVKIg

Post your Mustang specific questions here on Stangnet and you'll get good, solid technical information

Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Notice the brass fittings on the picture below – they screw into the spark plug home and then the test gauge screws into them


Your local auto parts store may have a compression tester to rent or loan if you have a credit card. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.


With the engine warmed up, remove all spark plugs and prop the throttle wide open with a plastic screwdriver handle between the throttle butterfly and the throttle housing. Crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 PSI. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.

I generally use a big screwdriver handle stuck in the TB between the butterfly and the TB to prop the throttle open. The plastic is soft enough that it won't damage anything and won't get sucked down the intake either.

A heavy duty battery charger (not the trickle type) is a good thing to have if you haven't driven the car lately or if you have any doubts about the battery's health. Leave it connected while you are cranking the engine and it will help keep the starter cranking at a consistent speed from the first cylinder tested to the last cylinder.

Jennifr said:

Hi Steel1. The screen was there and looked brand new and clean. The car idles fine and runs really strong, very frustrating. I don't know how to do a compression test so I guess I will have to take it to a shop.

Click to expand...

Yeah looks like your engine needs a little further investigation, could be bad valve seals, rings etc.
jrichker gave you a good link on diy testing, you could rent the test equipment from your local parts store if you wanted to give it a try.
If not find a mechanic you trust and have them run the tests so at least you know where you're at.
Good luck!