donvier

my recently acquired 65 cutlass has obviously got some problems that im working with. my biggest one right now is when its running it is blowing oil out of the oil fill tube. Currently this has a solid cap on the valve cover and a breather on the fill tube (no PCV valve)

Do you guys have any ideas on why this maybe happening? i'm pretty sure i can stop it by putting a breather on the valve cover but i dont want to just mask the problem.

How hard is it to put a pcv valve? does it just go in where the current fill tube is and run the line to the carb?

Thanks in advance

Olds64

Put a PCV valve on one of your valve covers, a breather on the other and put oil in your oil fill tube. To my knowledge Oldsmobiles never had an oil fill cap on the valve cover.

donvier

so i should drill a hole in my other valve cover and put a breather in it? Would it be a bad thing if i mixed that up a bit and replaced the tube with the PCV valve and put the breather on the valve cover, and filled oil through the valve cover?

What do you think would be causing the extra pressure?

I think on another post someone had recommended replacing the tube with the pcv valve to cut down on road pollution?

rocketraider

There's a gizmo on early 65 valve covers that looks like a breather element, with a tube running to aircleaner snout and a small vacuum line running to the carb base. It is actually the PCV valve. Cars so equipped will have a breather type oil fill cap.

Won't try to explain its workings here, it's "different" from what you're used to, but it evacuates the crankcase back into the aircleaner using airflow instead of vacuum as later PCV systems do. At standstill the small vacuum line sucks crankcase gases thru the valve and into the intake for reburn.

Check the gizmo and make sure the flapper disc inside moves free. If it's gummed up and not functioning, you can clean it with solvent or new ones show up on ebay about every week.

donvier

That would likely be the problem. my valve cover has a little aftermarket looking cap that says in all entirety "Oil" with no breathing function at all.
the only breather i have found is the one at top of the fill tube. The PCV valve spout on the carb is capped (well has a hose with a screw in it) i would bet they replaced that piece with the little cap thinking it would be fine. its been this way for awhile, i can tell because the top of the hood is caked with old oil...

Redog

It sounds like the valve covers don't have any baffels in them

rocketraider

If the carb already has PCV provision, this ought to be simple (heard that before, haven't we?).

Go to parts store and get the correct D-shaped PCV valve grommet for the valve cover that has the oil cap plug. Install it.

Then get a PCV valve for 68-later Olds engine and install that in the grommet. Get suitable vacuum hose and run it from PCV valve to the fitting on the carb.

You can either keep the breather style oil fill tube cap, or if the other valve cover has the hole for it install a breather in it. Then you should have a functioning positive crankcase ventilation system.

Olds64

No. I'm sorry, I didn't look at the year of your car. Later Oldsmobiles had holes in each valve cover.