How to perform a compression test with a scope (Verus-Vantage)

Relative compression test using the Snap-On Verus. You do not need a Snap-on scope to do these tests. The same procedure can be followed using any Lab Scope.

Testing procedures shown:
- how to use starter current to determine cylinder compression
- how to synchronize the starter current pattern with an ignition firing event to determine exact cylinder location

Tools used:
- Lab Scope
- Low amp probe
- High amp probe (preferred)
- Secondary Ignition Pick-up

Related Videos:
- How to perform a compression test with a scope (Picoscope)
- Relative Compression Testing Variables (3 cylinders have no compression)
- How to check for a jumped timing chain or belt

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!

Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[Thefoxunit]

Just got the low amp clamp the other day. Looking forward to using it for easier/quicker diagnostics.
Love all of these videos! Very helpful!!👍🏻

[blablabla]

Great info and step by step on how to do this I just bought a modis and running a shop alone I need to learn these skills, thanks for great tech info videos.

[felplayvina]

I did this test with my old vantage and low amp probe set at 40 amp, really good test..Paul..thank you.

[triggera]

I definitely heard it. Your knowledge and information is gold.

[PaulysAuto]

Thanks for this video Paul, very good tests to know!

[integrityautocarehomeofthe]

Brotha Dan, THANK-YOU for helping me make a big difference in Auto Repair and showing our customers that those shops that can keep up with diagnosing and fixing today's CRAZY COMPLEX cars are just like a good Doctor..always learning and studying, even on a Sunday!  Dr Rob The Car Doctor over and out.... PS: Love your e-book as well.... :)

[BespokeRyan]

Very awesome video I will put more use to my verus edge and low amp probe, recently also took my DMM home so I’d get the most out of my tool and use the built in DMM

[MitzvosGolem]

Sometimes irregularities in starter itself draw can send a erratic signal .Very often most good mechanics car "hear" variations in cranking sound indicative of a low or Dead cylinder. Good test and use of scope. Thanks

[Loofles]

never even occurred to me to do a fast compression test like this..right on great video

[oscarventura]

Thank you Mr. Paul you really have a a flair to teach this important stuff.

[ScannerDanner]

@dreamer2355 no problem! thanks for the comment

[Zavodney]

Wow ive never heard of this method before. Very cool. Thank you sir

[ScannerDanner]

@JrUnKrownedKing
Thanks for your comment! It really means a lot.

[ScannerDanner]

@DerekLMartin I do but it is not complete yet, as soon as it is done I will post the link for you. Thanks for your interest and comment!

[ScannerDanner]

@MrKevg59 Depends what your market is. There is no better scan tool than a factory one, but if your an aftermarket guy like me and work on everything the Verus is the way to go. There are cheeper alternatives though, you could go with a Solus Pro and Vantage Pro which would cost you a few thousand less than a Verus. Snap-ons troubleshooter and component test meter is un-matched in the aftermarket for experienced based help.

[sureshbabu-flkx]

Great experience to my work shop . thank you very much sir

[ScannerDanner]

you can and the amp probe you buy does not need to be from snap-on.
thanks for giving me a chance and buying my eBook! I'll try to help you in any way I can.

[ScannerDanner]

@bartewer This test is used to determine the cause of the misfire, not which cylinder is misfiring. Imagine you are working on a system where the intake manifold covers the back cylinders. The middle cylinder in the back is misfiring as noted by misfire counters and a trouble code. You would need to sell a customer an upper intake R&R to inspect the misfiring cylinder for a lack of spark, fuel or compression. With this method you could identify a mechanical problem without removing the intake.

[sollykhan]

AWESOME video, Dan, Thank you for this great info filled Presentation, much appreciated, will watch more, BLESS 🙂😇👍

[joemikos]

Great job Paul! I'm going crazy at Car Care Ministry but in a good way. This past Saturday was our monthly Ministry's car repair day where our volunteers come in. We did about 13 cars!
My job is primarily diagnostics. I had to call two bad computers, both injector drivers as well as a clogged exhaust and there's the regular MAF stuff ect. I have to be accurate because as a Ministry our funds are donated and obviously we have to be good stewards. Plus as you always say and I couldn't agree more..."don't be a parts changer".
My problem is we don't have adequate diag equipment. My friend
Eric "ETCG" did get OTC to donate an Encore scanner which has been our go to scanner and we are very grateful for it. As of now we don't have any subscription service e.g. All data. We are hoping to upgrade due to the fact we are taking on more cars in light of recent publicity.
For "front door" (scope) type testing I'm limited to (no scope) a multimeter and Power Probe.
Anyway I was wondering if the old Vantage would work for relative compression.
That's something I think is in our reach. I've seen them on EBay for around $3-400. Just need to know if it does R C.
Thanks again Paul