compression test results-good or bad??
#1
compression test results-good or bad??
i did a compression test to try to figure out y my truck burns so much oil (1qt per 150-200mi).
all cylinders pressure rose with each stroke (if pressure built slowly i indicated it)
#1-165 dry/190wet
#2-143 dry/195 wet, built slow on wet only
#3-155 dry/180 wet, built slow on wet only
#4-145 dry/175 wet
#5-155dry/185 wet
#6-155 dry/185 wet
#7 125 dry/ 165 wet
#8 115 dry/165 wet
cylinders tested in following order 2,4,6,8,1,3,5,7
all cylinders pressure rose with each stroke (if pressure built slowly i indicated it)
#1-165 dry/190wet
#2-143 dry/195 wet, built slow on wet only
#3-155 dry/180 wet, built slow on wet only
#4-145 dry/175 wet
#5-155dry/185 wet
#6-155 dry/185 wet
#7 125 dry/ 165 wet
#8 115 dry/165 wet
cylinders tested in following order 2,4,6,8,1,3,5,7
#2
#4
i interpret #8 as a tad low, but ok.
and overall - i'd say its very good.
have you fixed your plenum?
do any plugs look worse than the others?
do you have any serious blue smoke at start, idle, or at rpm?
have you replaced your pcv? it might be stuck open, it should rattle.
and overall - i'd say its very good.
have you fixed your plenum?
do any plugs look worse than the others?
do you have any serious blue smoke at start, idle, or at rpm?
have you replaced your pcv? it might be stuck open, it should rattle.
#6
#7
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#8
Generally speaking, I have always told people when it comes to compression tests on worn/used engines, the lowest compression reading should be no less than 75% of the highest reading. So in your case, the highest value is 165 psi (dry)/190 psi (wet) , so you should not get a reading of 125 psi (dry)/143 psi (wet) or lower on any other cylinder. But a true compression test should be done when the engine has reached operating temperature. Although, based on #7 and #8 the rings could be bad or it could be bad valve seals.
#9
well i did give the order i tested the cylinders for a good reson-so u wuld know ther was some cussn and thrown stuff tryn to get the compression tester tube in to a couple of those damn heat shield so the last cylinders tested wer cooler. i did all the cylinders dry then all the cylinders wet. haynes manual says no less than 100 psi... and if you get a low reading to do a wet test, but i did them wet anyhow even tho they wernt low. i may have put to much oil in them, idk. my thoughts are that since the readings are so damn good i wuldnt even take into account the diferences b/w wet and dry, but idk u guys are more experienced than me. i wuld just buy an airgap and call it a day but i did the plenum test and it showed pressure, no vac. it seems that both bad valves and bad rings wuld give low readings. but idk guys anymore suggestions?
#10