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Discussion Starter #1 (Edited)
ok, i realized that when i installed my rebuilt head (93 sentra) I did not lube the bolts and washers (which probably threw off the torque readings?) AND I reused the old bolts from the 220k mile engine, without detorquing and retorquing. I am now thinking that this is what was causing my very low compression readings, widely inconsistent I might add. If I am not mistaken these are torque to yield bolts and should not be reused in the first place. Also, I remember taking off the the oil filler cap to look into the head, and faint wisps of steam which smelled like fuel when I stuck my nose to it, came out. Could this be cylinder compression escaping into the head through the gasket? Its not the valves, the head is freshly rebuilt.

REading 1 - 115, 80, 100, 80
REading 2 (oil added) - 140, 105, 110, 105

I originally thought that the increase in psi on reading #2, due to added oil, meant that the rings were to blame, BUT I am also told that the amount of increase might not be enough to accuse the rings, but maybe just be the fact that the engine hadn't built up sufficient oil pressure to begin with.

Which brings me to my other question? I know you should initially crank the rebuilt engine over until oil pressure builds up, before you hook up the ignition components....but my car doesn't have an oil gauge in the dash, how many times should you crank?
 

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rnbd81 said:
ok, i realized that when i installed my rebuilt head (93 sentra) I did not lube the bolts and washers (which probably threw off the torque readings?) AND I reused the old bolts from the 220k mile engine, without detorquing and retorquing. I am now thinking that this is what was causing my very low compression readings, widely inconsistent I might add. If I am not mistaken these are torque to yield bolts and should not be reused in the first place. Also, I remember taking off the the oil filler cap to look into the head, and faint wisps of steam which smelled like fuel when I stuck my nose to it, came out. Could this be cylinder compression escaping into the head through the gasket? Its not the valves, the head is freshly rebuilt.

REading 1 - 115, 80, 100, 80
REading 2 (oil added) - 140, 105, 110, 105

I originally thought that the increase in psi on reading #2, due to added oil, meant that the rings were to blame, BUT I am also told that the amount of increase might not be enough to accuse the rings, but maybe just be the fact that the engine hadn't built up sufficient oil pressure to begin with.

Which brings me to my other question? I know you should initially crank the rebuilt engine over until oil pressure builds up, before you hook up the ignition components....but my car doesn't have an oil gauge in the dash, how many times should you crank?
So this is a Sentra we're talking about. Wasn't sure, before. In that case I may be in error about the thread bolts needing lubrication. However, if you did use TTY bolts, that would indeed be the source of your problem. At this point it may be too late to do anything but takle it apart and redo what you did. Except this time with new headbolts. The new gasket is likely blown again, so it will need to be replaced.
 

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Discussion Starter #3
So this is a Sentra we're talking about. Wasn't sure, before. In that case I may be in error about the thread bolts needing lubrication. However, if you did use TTY bolts, that would indeed be the source of your problem. At this point it may be too late to do anything but takle it apart and redo what you did. Except this time with new headbolts. The new gasket is likely blown again, so it will need to be replaced.
the haynes manual states that you should oil the bolts before you install them, and the washers too..yea, I took it all apart again, gonna get a new gasket and new bolts, and try it again
 
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