How to EASILY Diagnose Engine Connecting Rod Knock! Spun Rod Bearing

Freddy shows you how to diagnose engine connecting rod knock or spun rod bearing and goes through the steps to find out if it's a connecting rod knock, and which cylinder it is.

Tools I LOVE

Equipment I use

The Auto Alliance:

[lh]

Love the way you did the step by step with this AND got really close with the camera to show us. I could actually do this myself with the right tools.😊 I love learning car stuff

[RallyLancer]

Knock knock. Who's there? Cylinder 3

[mykline]

Good troubleshooting. I like the way you found out which cylinder had the rod knock.

[BoostedSpeedDemon]

Honestly how I've always found a rod knock, is to just pull the spark plug wire off of each cylinder as it's running, and whichever one stops knocking when you pull off the spark plug wire is the bad cylinder, and generally you can tell it's a rod bearing because if it was piston slap or a wrist pin, it tends to continue knocking even with the spark plug wire off.

[ORego-emyf]

Great video my man! Kudos for taking that challenge, enjoyed it much! And it was cool to see the extension used to find rod knock!

[mojo_m]

Great video and great tip!! I really like how you put together the clip--editing and close-up!

[stephenkulawinski]

First commercial I think I've actually enjoyed ever on YouTube

[RodknockRhett]

Easier to do this old school trick. Unplug one coil or spark plug wire (depending on your car). Start it. Does the knock sound quieter? If not, repeat for each cylinder. If it never get's quieter, than it must be something else.

[hacksbuilding]

Great video man. I've got some diagnosing to do on my ranger and I've been clueless on how to find the knocking rod

[Ockhamcool]

Make life easy on yourself. Pull the plug wires, one at a time while the engine is running. If you have connecting rod noise, you'll hear the noise go away or get a LOT less when you pull the plug wire on the bad cylinder. This is because the cylinder with the bad connecting rod clearance (which is where the knock originates) is no longer "loaded" except by the intertial mass of that connecting rod/piston. The noise will get much softer, because there is no combustion power stroke to cause the piston to slam down against the loose rod bearing.

[tonycstech]

Poor man doing everything him self is my kind of club.
Thank you.

[cb]

used this method on a 2004 corolla, found cyl 4 had bad slack. Thanks!

[MrBojangles]

Brilliant! Few will share this information. Thank you.

[williamcavalier]

Thanks, after listening to that Kia I'm certain my L61 is toast.

[carlodonnell]

It is easier to use that method with an inline vertical engine; but how would it work with a V-ENGINE with the cylinders on a slant?

[ghanatekton]

Excellent video thanks. I have more understanding of the sounds. But it’s hard to hear what your heard. But I’m not as exsperienced

[LyfUninterrupted]

Is there a way to diagnose a bad piston wrist pin? Engine shop is telling me my Triton V10 has piston skirt slap on #6 cylinder which requires a new engine. Compression is fine and the engine runs great other than the healthy knock.

[Boz]

just found your channel thans for the info im diagnosing my lawn mower... hehe poor mans mods heheh lawn mower...

[neilgreen]

Great video. Thank you for taking the time to make it.

[juliosdiy]

2018 wow what a freaking driver destoying that baby. Now someones left with a messup cylinder.