Minimum cylinder pressure
#1
Minimum cylinder pressure
99 EVO engine, at least 48K miles - giving me hell not starting when it is cold. Only hits on front cylinder. Done all of the ignition checks (plugs, wires, swaps, etc), all AOK. Checked rear cylinder pressure - 88 pounds - did the oil-add - same. No, haven't checked front, have to remove tank to get tester in place. Am I at the point of needing heads done? Dumb question - can heads be removed without pulling engine? Thanks.
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#3
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99 EVO engine, at least 48K miles - giving me hell not starting when it is cold. Only hits on front cylinder. Done all of the ignition checks (plugs, wires, swaps, etc), all AOK. Checked rear cylinder pressure - 88 pounds - did the oil-add - same. No, haven't checked front, have to remove tank to get tester in place. Am I at the point of needing heads done? Dumb question - can heads be removed without pulling engine? Thanks.
I wouldn't stop at the heads though I would take off the jugs too so that you can inspect them and the pistons as well.
All of this can be done with the motor in the frame.
#5
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cyl. comp. test.
99 EVO engine, at least 48K miles - giving me hell not starting when it is cold. Only hits on front cylinder. Done all of the ignition checks (plugs, wires, swaps, etc), all AOK. Checked rear cylinder pressure - 88 pounds - did the oil-add - same. No, haven't checked front, have to remove tank to get tester in place. Am I at the point of needing heads done? Dumb question - can heads be removed without pulling engine? Thanks.
Your description of " did the oil add - same " dosent compute ?
Correct procedure for cylinder compression test is ... run motor to operating temp., ensure you have a fully charged battery , remove both spark plugs , ground out both spark plug wires or disable coils , install cylinder pres. gauge into spark plug hole , open choke , open throttle completely and hold open , rotate engine for 10 seconds and observe the gauge. Comp. should rise evenly to a maximum reading and stabilize there.
Record the reading and do same for other cylinder.
Next ... add an ounce of motor oil into the cyl. to be checked a second time , wait 5 min. for the oil to migrate , do same procedure as above and record the readings for each cylinder.
Last ... You should show approx. 90 lbs. for each cyl. in the first check.
You should show a higher pres. for each cyl. after the oil added step.
What is important is the difference in readings between both cylinders.
If you see a difference of more than 10-15 lbs. between both cylinders you have a rebuild in your future.
Be advised that a compression test is a start point only. Other inexpensive test procedures are available to specify a particular area of possible problems like valves etc.
#6
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How are you doing your cyl. comp. test ? No reason to remove tank.
Your description of " did the oil add - same " dosent compute ?
Correct procedure for cylinder compression test is ... run motor to operating temp., ensure you have a fully charged battery , remove both spark plugs , ground out both spark plug wires or disable coils , install cylinder pres. gauge into spark plug hole , open choke , open throttle completely and hold open , rotate engine for 10 seconds and observe the gauge. Comp. should rise evenly to a maximum reading and stabilize there.
Record the reading and do same for other cylinder.
Next ... add an ounce of motor oil into the cyl. to be checked a second time , wait 5 min. for the oil to migrate , do same procedure as above and record the readings for each cylinder.
Last ... You should show approx. 90 lbs. for each cyl. in the first check.
You should show a higher pres. for each cyl. after the oil added step.
What is important is the difference in readings between both cylinders.
If you see a difference of more than 10-15 lbs. between both cylinders you have a rebuild in your future.
Be advised that a compression test is a start point only. Other inexpensive test procedures are available to specify a particular area of possible problems like valves etc.
Your description of " did the oil add - same " dosent compute ?
Correct procedure for cylinder compression test is ... run motor to operating temp., ensure you have a fully charged battery , remove both spark plugs , ground out both spark plug wires or disable coils , install cylinder pres. gauge into spark plug hole , open choke , open throttle completely and hold open , rotate engine for 10 seconds and observe the gauge. Comp. should rise evenly to a maximum reading and stabilize there.
Record the reading and do same for other cylinder.
Next ... add an ounce of motor oil into the cyl. to be checked a second time , wait 5 min. for the oil to migrate , do same procedure as above and record the readings for each cylinder.
Last ... You should show approx. 90 lbs. for each cyl. in the first check.
You should show a higher pres. for each cyl. after the oil added step.
What is important is the difference in readings between both cylinders.
If you see a difference of more than 10-15 lbs. between both cylinders you have a rebuild in your future.
Be advised that a compression test is a start point only. Other inexpensive test procedures are available to specify a particular area of possible problems like valves etc.
I haven't checked it after the rebuild but I'm sure it is higher now.
#7
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