Continuation of a thread I hijacked last summer. I finally got around to ordering my pump and injectors. The truck hasn't been started all winter and while I had the pump and hard lines out of the way, I decided to check compression before I remove the old injectors. I didn't think of it until I was done, but did I cause myself any trouble by turning the engine over with the injection pump removed?
I'm changing out my glow plugs as well, so removed all of them before compression testing. All cylinders measured between 330 and 350 as guestimated by the position of the needle, my gauge is only numbered to 300. When I did #6, however, it made a funny sound that I don't want to call chuffing, but I'm afraid it is. I tested it three different times, and it was the only cylinder that made the noise, and it was coming through the intake screen. The first test of #6 was just over 300lbs but the second two tests put it with #7 and #4 at about 330lbs. This was of course on a cold engine, that hasn't even been turned over in months. The order I tested in was 5,6,7,8,4,3,2,1. I don't know if it matters or not, but maybe after cranking through the testing of all cylinders something would seal up a little. The sound never went away, however, but the compression was better on that cylinder on the second and third test. When I was using this pickup last summer, I never heard anything funny while it was running. The only reason I'm digging into it is to replace pump, injectors, return lines, and glow plugs. I'm trying to get to the bottom of my crankcase filling with diesel, and the injection pump was the old style with no weep hole.
I'm thinking of completing the job and running the engine to see if I can detect any odd noises. Are my findings even legitimate since I'm on a cold engine that has been sitting a while?