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Discussion Starter · #1 ·
What should the readings be on a stock 99 4V? Should all the cylinders be within a certain amount of each other? The readings varied by about 10% to 12% between each cylinder, with all of them at least 160 psi and a few at about 175 psi. They all held their pressure pretty darn good, droping down 5 psi in about 10 seconds or so from the max psi.

Any info on this would be appreciated.
 

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DanTheCobraMan said:
What should the readings be on a stock 99 4V? Should all the cylinders be within a certain amount of each other? The readings varied by about 10% to 12% between each cylinder, with all of them at least 160 psi and a few at about 175 psi. They all held their pressure pretty darn good, droping down 5 psi in about 10 seconds or so from the max psi.

Any info on this would be appreciated.
Anytime the cylinders are within 20 percent of each other you are good. The pressure will drop some because of ring end gap.
 

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Discussion Starter · #3 ·
So I wonder if it's my valve guides that are bad? I'm getting way too much oil consumption and my tailpipes have way too much black soot built up in them. I opened my butterflies and rubbed my finger inside the intake and there is a thick film of oil in there. If I run my car with a timing of below 13, it runs like crap, like I got bad gas, but I don't. My guess is that too much oil is getting into the combustion chambers and effectively reducing the gases octane level, thus running like crap with lower timing.
 

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Small oil consumption problems would not likely show up on a compression test or leak down test. we have actually pulled 4V engines apart with less than 30,000 miles on them and everthing looked great but the oil rings were wore out.
 
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