I finally got this F-350 4x4 tooling down the road.... took off plugged exhaust.... new edelbrock 4bbl.... compression tests from 135 to 150..... not too bad..... I have 2 strange discoveries I'm looking for some advice on.....

When I removed plugs for compression test, plugs 1, 4, 6 & 7 all had the metal prong either partially or total smashed almost down to even with the top of the threads... I decided new plugs (old were Bosch Platinum, replaced with std. Bosch) I figured the worst that could happen is another collision course... I gritted my teeth and she fired up with new life... took her out for a 5 mile ride, came back checked bad plug locations and all looks good......

After getting excited about the revived power and pickup, I took her out a ways further from shore... this time probably 10 to 15 miles, giving her a little throttle to clean out that backed-up exhaust mess.... anyhow, when I pull back in, oil is everywhere and I'm about a quart and a half low... I decided the soild oil filler cap was causing the crankcase pressure to build up...... I ran with my 84 F-150's 302 cap with hose and got little to no oil leakage with almost no change on the dipstick..... can the lack of venting the opposite valve cover from the PCV side cause that much problems..... now that all my seams have been exposed, what would you recommend, replace all oil-holding gaskets?, definitely a job for some degreaser and scrubbin...... sorry for the long post

one more thing... I have the 2-1/4" stock exhaust up to where the cat used to be... there is a 2 foot piece of 2" before exiting... could this still be creating a little too much backpressure along with my cap to add to my mess

 

If the PCV system is functioning correctly the PCV valve will be evacuating excess pressure/oil/blowby vapor from the crankcase through 1 valve cover and fresh air filtered through the crankcase filter will be pulled in through the vented cap & hose in the other v/c. If you had a solid cap on the vent side then the PCV would be creating a vacuum in the crankcase assuming it's functioing correctly. Theoretically this shouldn't cause the oil to leak out of wherever it was coming from. However since you solved the problem by installing a vented cap & hose on the "intake" side of the PCV system I would guess the additional "venting" provided by the vented cap/hose was actually allowing the crankcase to "depressurize" which caused the oil to stop leaking. From your description I would say that the PCV system is not working right. I'd check the valve and hose.

 

I think your original plugs had too long a reach.

 

The vent side of the PCV system will let any excess pressure out from blow-by that the PCV valve can't handle.

 

Maybe a carbon build up on the top of the pistons, from the clogged exhaust.

This will mash your plug gap.

 

I agree with you Bill, you would think that the vacuum from the PCV would suck out and equalize the crankcase.... I did remove the PCV with the motor running and the thing sucked to my hand so quick it made me jump... so I know shes working... my only thought is idling (high vaccum) the motor would not show signs of leaking... after running it under load with throttle (lower vacuum) the oil began to spew.... I thinking that the pressure needs relieved more-so under high throttle conditions thus my vented cap helping out... any how I replaced my air cleaner with the edlebrock that has a vent adapter and added an edlebrock oil breather with nipple and connected with 1/2" hose... I'll be running her this weekend after all fluids get changed.... I noticed another dilemma, wet rear axle tube, wobbly yoke on rear output of BW 1345.... what have I got myself into, anyway, keeps me off the road for now... thanks for all replies