HELP! Air rushing out of my oil cap & dipstick

[Hessian]

Some quick background:  I bought my 69 Charger R/T before I went on my last deployment.. after a unbelievable horror story with "Passport Transport" it was delivered (read: dumped off damaged after almost two months   ) just days before i deployed.  SO, there it sat except for a few bi-monthly start ups and local drives here and there by the wife to keep everything running/lubricated.  

Thats the background... so today I go out and start it up for a nice first day of fall drive.  I start it up, back it out of the garage... turn it off and go to check the oil... as soon as I pull out the dipstick, I'm met with a looooongggg  "Hissing" sound as air comes rushing out.  I replace the dipstick and take off the filler cap... same thing.    

I added some oil, started the car again and turned it off... same result.  Oil press holds at about 50

BTW, this car is a 69 BUT has a 5.7 V8 Hemi...  

Anyone have a rough idea of what could be causing this?  I have checked the oil several times since I got it and never experienced this problem.

Thanks in advance!    

[charger Downunder]

Dont know about the new style engines if it was an old one i would say no pcv valve or breather on rokers.

[elacruze]

I hope I'm wrong, but that much air usually means you have piston/cylinder wall damage. Does it idle smoothly?

[Hessian]

Gulp... 

I hope that's not it...   It does idle smoothly.  I guess a compression test should be the next thing?

[JB400]

I strongly agree with the compression test. Any ideas how many miles is on the engine itself?

[Hessian]

Seller said 44k on the donor engine.... he was/is a member here.  I've put less than 100 miles on this car....

[elacruze]

It is possible under the right conditions for the piston rings to carbon up and stick in the lands, ruining the seal. This usually happens to engines that don't get their oil changed soon enough, and get a lot of short-trip driving. Add a pint of Diesel fuel to the crankcase, let it idle for 5 minutes or until full warm, then change the oil and filter. Add in a quart of Marvel Mystery Oil to the change, and monitor the blowby. Try to run the first tank of gas out all at one time on the highway, hold it out of overdrive if necessary to keep the RPM up at 2500 or better. If it starts getting better within the first 50-100 miles, it's probably going to be ok. If it doesn't improve, then just drive it until something bad enough happens to force you to take it out. Which may be a very long time, even if it's a little hurt.

[Indygenerallee]

Is it carbed or FI? Newer Hemi's do have alot crankcase pressure. If it is a carb setup I would recommend a PCV valve.

[Hessian]

Its fuel injected.  I was going to try and replace the PCV but I can't find it... Anyone got a pic of where this thing is at on a 5.7 Hemi?

[Cooter]

Depends on year as to where it's at, but some are right on the side of the oil fill. Twist to unlock and twist to lock..These can be a PITA to get out.