Cummins blow by
 

So I know this has been discussed somewhere down the line but I was just needing some info. Recently I was having some issues with my fuel mileage an a buddy of mine said that I could be losing compression causing the drop in mileage. So my question for all of yall is: if I was losing compression wouldnt it show more signs ie: low oil pressure, hard starting in cold weather, and oil consumption? Also Ive rerouted my blow by tube so that it comes up an runs down beside the valve cover an down to the top of the starter. Ever since I rerouted it Ive noticed that theres alittle bit steam coming from the tube and maybe every now an then alittle bit oil drip from the tube but not often. Now its not pumping out like a frieght train but theres alittle and theres just alittle puff when I remove the oil fill cap. Ive been wondering if the vacuum pump could be the causing the steam making it seem like theres excessive blow by. So is there any hard proof signs of losing compression other than a compression test? I know thats the best way to find out but I cant afford to have the ol girl down in a garage lol. Sorry for making this so long but ever since my buddy told me that Ive been paranoid/over thinking about it lol. The truck only has 202,xxx miles on it an it still runs great. Thanks for any help or info fellas:c:

That sounds like reasonable blow by. Mine is about the same way. It should start hard in cold weather if the rings are really bad.