That Sounds TERRIBLE! - Bad Engine Sounds. What They Mean And How To Make A Diagnosis On The Fly

Comments · 459

• AN

  @AnthonyPerna2 · 3 years ago (edited)

  Tony the best thing I've found to listen to the sounds in an engine is a mechanics stethoscope, but you remove the metal rod it comes with, and stick a piece of 3/16 brake line in it. I could pick up everything it was amazing. Also a while back I bought a 75 coupe Deville that sat from 1979 until 2018, I started it and after a little tapping, the motor was smooth as hell and quiet, until you revved it. It sounded like a bad rod knock, I ran it down the street to get gas and it wasn't registered, some one pulled out in front of me so I punched it to avoid the accident. I thought I was going to send a rod out the side of the block. All the sudden the noise went away, it was a stuck lifter.

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• CA

  @carwashadamcooper1538 · 3 years ago

  I&apos;ve been able to diagnose engines, electric motors, hydraulic pumps and power units, bearings and pretty much everything that moves by nothing more than sound since I was a kid but you still managed to teach me something. <br>Thanks Tony.

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• MR

  @mraycgz · 3 years ago

  The best false &nbsp;rod knocks are the ones that get diagnosed BEFORE the motor gets torn down and put back together. The ones that don’t are a heartbreak.

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• PA

  @pappamike6231 · 3 years ago

  Even though I&apos;m merely a shade tree mechanic and will never do most of the services to a vehicle that you explain. I still enjoy watching and learning.

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• SP

  @Spike-sk7ql · 3 years ago

  As soon as you mentioned the early Buick 3.8, I knew you were gonna say the damper was the problem. I did the exact same thing, but I didn&apos;t get as far as to completely pull the engine. I was just gonna pull the balancer to give myself more room to pull it, and noticed the broken damper. Customer was super happy that I noticed that before the engine was on a stand.

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• HE

  @HeadFlowInc · 3 years ago

  When the spring under the pump arm of a mechanical fuel pump breaks it sounds exactly like Rod Knock! &nbsp;Great relief to only replace the fuel pump! &nbsp;👍

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• CA

  @captainjohnh9405 · 3 years ago

  Tony, This video was a wonderful, well oiled, version of the old videos you did .... like the porting video and the valve grinding videos. &nbsp;This is absolute gold! &nbsp;This is the knowledge you provided early on, but now in a more polished form. &nbsp;Outstanding! &nbsp; Keep these types of videos coming... and maybe throw a stunt carb now and then.

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• MI

  @MikeBrown-ii3pt · 3 years ago (edited)

  Many of the old Pontiac Iron Duke 151 C.I.D. (2.5L) 4 cylinder engines used from the 60s through at least the late 80s in various forms were notoriously noisy due to having a gear drive instead of a timing chain or belt. They actually do make a rhythmic sound that mimics a spun rod bearing. However, while it does indeed change with engine speed, it doesn&apos;t get worse over time.<br><br>I also had a Ford 300 straight 6 that was so worn out that the piston slap on cold starts sounded about like 6 rocks in a coffee can! That old truck had been used and abused as a dry cleaners delivery van for at least 10 years, and God only knows how many miles before I got it (for REALLY cheap) so, I just lived with it. I ran it daily for another 5 years or so before it finally couldn&apos;t take any more...Rust In Pieces Ol Reliable!

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• SU

  @superrodder2002 · 3 years ago

  Funny how right in the middle of you talking about lifter ticks, a ford commercial pops up. LOL &nbsp;I spit my coffee out laughing so hard

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• SL

  @slicknick9962 · 7 months ago

  I just want to thank you so much! My truck started making a knocking noise n I didn&apos;t know if it was a rod, lifter, valve or what I had no clue. But after watching your video n you said that the rhythmic noises were internal components and non rhythmic were external gave me hope again. So I took my belt off and no more knocking. Now all I have to do is figure out which component is giving me hell. Thanks again! Oh I would love to help you out n send some cash but I don&apos;t have 2 dimes to rub together cause my truck is the only way I have of going n I&apos;m self employed so ... I didn&apos;t know what I was gonna do. You&apos;ve been such a blessing!

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• CH

  @Channelscruf · 3 years ago

  I am what is commonly known in some circles as first.

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• DA

  @danielesilvaggi · 3 years ago

  I had just rebuilt a stock Chevy 350 and it&apos;s on the engine start up stand and when I started it up the first time I heard a clunking sound and immediately shut it down. I then took the oil pan off and checked every rod and found nothing ( no spun bearings and clearances were spot on ). So put it back together and started it up and it was there again but this time I left it running and walked around the motor and you&apos;ll never guess what it was. One of the rockers was hitting the vent box on the inside of the valve cover. took it off and bent the metal over enough to clear it and the noise was gone. Whew!!! I have a video of the sound but no way to put it on here. Crazy shit. Thanks for the videos Tony.

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