I was doing a 60k tune up on the Maxima yesterday when I lost the stupid PCV valve in the back of the engine. But luckily I had the old one to put back in. The only problem was that I did not put it all the way in down into the hole. I dont think I am have having any problems.

Will it ruin anything if I leave it like that for too long??

I did drive it after this with no problems at all from what I could tell.

 

No problem at all. The engine may digest a small amount of unfiltered air, and the oil may be diluted a little with fuel in blow-by gas. If it's only a few hundred miles or so I wouldn't worry about it.

 

Thanks UncleMax. Its in place just not very secure right now.