Is it better to disconnect and remove all the plugs before testing? Other than helping the battery, I'm not sure if
this would alter the readings.
I have a Sears compression gauge and it specifically says to HAND TIGHTEN ONLY. I'm not sure if I'm doing this correctly,
but on the last car I tested, I tightened the gauge by twisting/spinning the tubing. How else are you suppose to tighten
the gauge and how do you know if it is tight enough since I cant use a tq wrench?
Yeah that is the right way to tighten the tester! Just use your hands as for the testing itself I wouldn't see why removing all the plugs would alter the readings since all cylinders are single combustion chambers. Someone correct me if I am wrong! I might have done my compression testing wrong! :)
I don't know about doing it wrong... but if the battery was weak, maybe the readings could be skewed. :conf:
I always pull the plugs. :dunno
Hand tighten it down by spinning the tube, i wouldnt take all the plugs and coils out at once, just do one at a time to minamize the change of crap falling into the motor, and you want to put the same coil and plug back into the same cylender because that takes away chances of not being able to diagnose a motor problem later in time.
Pull the fuel pump fuse and start the car and wait for it to die.
Keep that fuse pulled and pull the ignition relay (as a saftey).
Then test the cylenders, you should get more than a 10-15% diffrence in pressure. The pressures tend to drop as you get closer to the firewall, temps increase.
Good luck!
Also,
a weak battery or starter changes results of the test as do worn piston rings and valve seals.
hand tighten by spinning the tub yes. Just keep doing it until the reistance is there, you will feel it. Also, all plugs need to be removed. There is a reason for it, I learned it at school, but alas I have forgotten.
Seems like we're still getting mixed results.
What is mixed?
If your getting poor readings.
Pour a cap full of 15w-xx oil into the cylender wait a few secounds then test.
Thats called a "wet test"
What this does is help you figure out if your rings are shot, if compression increases your rings are on the way out or are already shit.
I meant some are telling me (on and off the board) to leave the plugs in and some are saying to remove all of em'.
