How To Diagnose An Engine Knock.MP4

Engine noises aren't to hard to diagnose if you follow a few steps.

[Loebane]

Thank you! I've been looking for a good example of spark knock. Now I'm a lot more confident in tuning my megasquirted engine.

[MMSDK]

1:16 loving the RF interference from the spark....lol. Thanks for uploading this.

[olobaltierra]

Brand is not the issue, like all things with time they deteriorate. The key is to keep the car well maintained and not ignore it's small issues. one should get in the habit of checking and tune their cars. You drive it everyday it gets you where you need to be, it takes care of you so you must do the same.

[SavageThrifter]

Lord help me, I swear there are like 15 different engine problems that have the same damn noise. I can't tell 🤷‍♀️

[eot]

I had something like that, and it turned out to be a hydraulic lifter. Oil pressure is what makes them expand and take up the slack between your cam and valve bucket. If your lifter has grime in the oil hole (or you're using thick oil), it may not get enough oil pressure until you hit 1k RPM. Use heartDixie's method (garden hose on your ear) and listen to the valve covers to check.

[MPCWatkins]

This is great. I appreciate the lesson. You have a great channel for a home mechanic like myself. Thank you for your time and effort.

[IndyGSR]

If the knock is more pronounced or frequent when you rev the engine, it's almost always rod knock, likely due to worn connecting rod bearings. A bad piston wrist pin can make a similar noise, but it's usually much quieter than a rod knock.

[ComradeAlpharius]

Thanks this video was a huge help. I was worried I had an engine knock, but it's extremely consistent. The problem is hopefully something more benign, hopefully just a fan or a misplaced piece of plastic.

[robinibor]

NOT SO FAST. From what I could tell from the video my Ford 2.0L (same basic engine) was making the same exact noise. As it turned out for me, the real explanation for the noise had nothing to do with the internal engine components. It was a partially working fuel injector. It turned out that noise was not "piston related", it is instead pinging in just one cylinder! (OK, technically pinging noise made by the piston, but that is not what you were getting at). The bad injector causes the air/fuel mixture for that cylinder to be way way overly lean, thus ping badly. It should be noted to, there was a noticeable decrease in power if this is the case too. So before anybody else junks their car for what is a extremely easy fix, always ask what else the result of this test could mean. The list is longer than what you said in the video.

[rorysmith]

I like your plug boot pliers ....I learned the hard way not to use your hands. ZAAAAP...HAHAHA! THAT SUCKED.

[coreytait]

Its most likely a lifter tick before you tear it down i would try running reslon in your oil. it might take the knock away but when u run reslon through your oil make sure u change your oil after a tank and half of fuel. if it dose not take the knock away i would then take the valve cover of and get someone with experience to adjust the lifter. And for peaceandwellness if u think thats a bad ring or valve your crazy. if u are truly a mechanic for 30 years u still have alot of learning to do .

[Mikeshawtoday]

Wow. Super helpful. My engine has a bad knock when I accelerate and just before shifting gears. I can't wait to try this spark plug test! Thanks!

[revejmal]

Might want to check the blinker fluid or the waffle bearings....

[TheCody]

@howmuchtimeisleft
He actually said it would remove the combustion pressure. The force of combustion pressure is much greater than compression. Without that spark, the piston will not be propelled on the power stroke the way it would have, had that mixture ignited. This changes the sound of the rod knock by reducing the amount of load the rod bearing has to support on that power stroke. (where that knock is likely most present)

[jdz]

A collapsed piston skirt will make that same sound, no noise when plug wire removed, piston slaps under combustion about 700 rpm or so above idle.

[indionysus]

I have 155, 000 on my 94 1.9l, that spark plug is always tough to get off; still running great! Trying to work on a 2.2l chevy, has some noise and some oil pressure problems; took off the valve cover rockers look fine, still thinking it is a lifter.

[defyingtheodds]

Great video. Thanks for this. I can use this knowledge in the future.

[austin]

Disconnect the wiring from each one individually. Works the same as removing the plug wire. And you're less likely to get shocked by just disconnecting a coil pack.

[georgestrickland]

its a 1.9 escort motor, these were not nearly as likely to drop valve seats as the 2.0 ford motor, they didn't have nearly as much power as the 2.0 but were pretty much bulletproof if properly maintained.

[mikeshotrodshop]

By removing the spark your removing a stroke? No, all the strokes are still there, it's just not lighting the fuel/air charge. It does change the pressures associated with that piston but it will do no harm to your engine. This works well to locate problems associated with a cylinder with, say, a broken piston skirt, bad connecting rod or bearing, wrist pin, or just a worn skirt to wall.