I decided to check the compression on my 217K E320 and am getting a respectable 182-187 PSI per cylinder. Normally, I've seen people satisfied and leave it at that, happy with 180 PSI+ and don't bother with a wet test.
I decided to do a wet test on Cylinder #1 just to see and got a whopping 268 PSI. I didn't do the rest of the cylinders as I ran out of time due to a rain storm coming through. Normally, (and it's probably true with this engine anyway) this would be considered worn rings, but would 270 PSI be normal compression even on a new engine? That's over 18:1 compression ratio, normally heard of in diesel engines!
So is this test just a fluke or should I have even bothered with the wet. I've never felt it to be that accurate due to the fact that it decreases the chamber size (although, not that dramatic). Maybe I put too much oil in there, but I can't image anything more than a tablespoon.
EDIT: 1996
I decided to do a wet test on Cylinder #1 just to see and got a whopping 268 PSI. I didn't do the rest of the cylinders as I ran out of time due to a rain storm coming through. Normally, (and it's probably true with this engine anyway) this would be considered worn rings, but would 270 PSI be normal compression even on a new engine? That's over 18:1 compression ratio, normally heard of in diesel engines!
So is this test just a fluke or should I have even bothered with the wet. I've never felt it to be that accurate due to the fact that it decreases the chamber size (although, not that dramatic). Maybe I put too much oil in there, but I can't image anything more than a tablespoon.
EDIT: 1996