Greetings,

I have a 460 in a 78 F150 that's blowin' oil all over the front of the engine. Turns out that the oil is coming up through the dip stick tube. Does this mean my rings are bad and causing a build up of pressure in the crank case?

Kevin K.

 

Maybe. Also could be too much oil in the pan, or could be a stuck PCV valve.

Good Luck,

Jim Henderson

 

Oil level is normal. Not even to the full mark. Where is the PCV valve? I have a breather on the driver side valve cover with a hose going to the air cleaner and PCV filter. I didn't think there was a valve in there, though.

K.

 

That's a PCV Valve that goes into the valve cover with a rubber grommet around it.
If it's plugged the air has to blow out somewhere.=dipstick.

Dennis https://www.ford-trucks.com/user_gallery/sizeimage.php?&photoid=1733&.jpg



Please Don't Ask Me Any Tough Questions As:
"I'm Saving My Memory For When I Develop Alzheimer's"


78 F-150 429CJ,Silver
w/Explorer Pkge.
641/2-Mustang 260,Pre-World's Fair Car.
64-Fairlane500 S/C waiting for a 390-4spd.
68-Mustang 289-Sunlit Gold 80,892Mi
78-Buick LeSabre 403 4V
84 Volvo DL Wagon

 

Ahhh. Thanks! I sure hope that's the problem. However, I have a feeling it's not gonna be that simple.

Thanks again!

K.

 

G'day!

Last night I checked the PCV valve and it's working fine. Lots of vacuum. Oil level is fine as well. I also checked the compression. Six cylinders were at 130psi, one at 110psi, and one at 150psi. The compression tester I used wasn't very good though.

Is this an "ok" level of compression? Anyone know what it should be, and if I'm at a dangerous level?

Thanks!

K.

 

I don't have my manual on me but the 110 reading seems a bit low. Usually I start to wonder when I see much below 150 on the guage(kind of depends on what stock compression should be tho). The 6 cylinders doing 130 might be normal, but the 110 bothers me.

You could squirt some oil into that cylinder and try another pressure reading. If it goes up to "Normal" then the rings are suspect. If it doesn't then the valve guides or maybe head gasket are suspect.

I am not sure of what is normal for a Ford, but like I said the low reading plus the fact that it is significanlty different from the average leads me to believe you may have some blowby.

By the way, carefully remove the oil filler cap and see what happens. If you get a lot of air pulsing out then you definitely have blowby, but then the dipstick tube probably is a good indication of this too.
Usually I expect a little back and forth kind of puffing from the filler hole. If you have a strong outward pulsing, trouble.

Good Luck,

Jim Henderson

 

Get a good guage first. Compression checking isn't a place for guessing. I think your 110 is low. I don't have the FORD book/specs in front of me, but you want all pressures within 10% of each other between adjacent cylinders.

Are you checking the pressures cold? On your suspect low cylinders, squirt some oil in them and check compression again. If pressures go up, its your rings.

I had oil spewing out of the dipstick tube once, and it was caused by a bad PCV.