Relative compression test.

Running a relative compression test with a Uscope.

[@alexgoldstein7997]

I have had one of these little scopes for automotive use for the last few years and It has come in handy a few times, great tool for the value!

[@gregsmobileautomotiveacrep1731]

Yeah, I like this one for a quick check on a sensor or 5 volt reference or compression test, I have moved up to a 4 channel that works with my Autel scan tool for some more detailed diagnostics.

[@randy1ization]

that starter draws more than 60 amps ???

[@carlodonnell146]

I think I prefer how that u-scope is set up with the choices shown first rather than the newer version

[@salceti]

I am wondering if I use my one channel uScope and record/save the waveform to my user reference file folder, then run a secondary ignition test could I then load the one test and overlay that with the second test referenced file to determine which cylinder is the low compression one? Just wondering if that would work.

[@carlodonnell146]

I tried that cranking test and I couldn't get the wave form to show ha I'll have to try again sometime

[@carlodonnell146]

I believe that all scopes should have at least two channels instead of buying a one-channel scope and then still have to get another one with more channels.

[@billwilliams6338]

GREGS MOBILE AUTOMATOIVE AC REPAIR, when one or more pistons are NOT giving any compression. What would be the problems on the cars engine? Do you have to replace the piston or the actual engine block is cracked inside that piston cylinder and have to replace the whole engine block?

[@gregsmobileautomotiveacrep1731]

If you are seeing one or more cylinders with no or low compression, it can be a couple of things, you could have failing piston rings, or a bent intake or exhaust valve, or a valve seat that is fouled. You could have a blown head gasket, or cracked head. In order to determine what is the cause, you will need to do some follow on testing with an actual compression test kit, doing both a dry and wet compression test on each cylinder will help determine if rings are to blame, doing a cylinder leak down test can help figure out if it is an exhuast/intake valve or head gasket issue. There's alot more than I can cover in a commebt section.

[@billwilliams6338]

@@gregsmobileautomotiveacrep1731 1.) The Actual Compression test kit will measure the PSI level of that No or Low compression cylinder? you will want the PSI level to be 30 PSI or more than 30 PSI to considered good? 2.) What do you use to do a Cylinder Leak Down test? I have seen technicians poor water on the cars engine to see if the head gasket is leaking or sucking in the water. If the engine starting to running funny misfiring while applying water on the value cover and head gasket this means that its the head gasket or intake value?

[@billwilliams6338]

@@gregsmobileautomotiveacrep1731 thanks for the help // I couldn't find a video of yours on how to test each gauge in the dashboard. How to test the oil gauge, temperature gauge, gas gauge, to check if they are good or bad how can you test them using what testing tool for cars 60's,70s, 80's, 90s gauges?

[@weldingjunkie]

Good video I love my scope. We’re you saying O scope vs uScope or O scope as in oscilloscope lol I’m not used to the phase. Good job on this

[@gregsmobileautomotiveacrep1731]

LoL, I am saying O scope as in oscilliscope. Thanks for the comment.

[@weldingjunkie]

Greg's Mobile Automotive A/C Repair that’s what I figured lol kept messing with my ears haha. Thanks for sharing this was good

[@tedgtfan]

Thanks, great vid. You mentioned a formula for PSI, where can I find this formula?

[@gregsmobileautomotiveacrep1731]

kzbin.info/www/bejne/a4uleXubjZaikKs Here's a link to another KZbin guy who explains it very well. Hope this helps.

[@tedgtfan]

@@gregsmobileautomotiveacrep1731 Thanks

[@keatongill8991]

ITS NOT AN O SCOPE ITS A U SCOPE

[@gregsmobileautomotiveacrep1731]

No, I was saying Oscope, because that is my abbreviation of Oscilloscope, I was not referring to the AES wave Uscope which is their product name. Thank you for giving me the opportunity to clarify this.