Engine knock (newbie)

[Kyle H]

I have a new (to me) 1998 gmc K1500 stepside with a 5.0l 305 Vortec. And I have an engine knock I have a small inclination about what it might be. Main or rod bearing. Push rod. Or idk but any help or possible other options that I dont know, are very much appreciated. Engine knock is light tap and seems to be from the bottom near the oil pan but I haven't taken it apart at all yet. Thinking worst case, its blown or maybe best case I read a better thing to check like timing or knock sensor. Please no judgment I dont know everything so break it down barney style for the new mechanic.

 

[Redneckgeriatric]

get out your camera and make a video of the noise, and at different angles around the suspected source. dont worry yet, may be simple.

 

[McBroom]

After making the video post on YouTube and then post the link here so we can help diagnose the problem for you.
We dont try to judge just offer advice when we can

The Blue Mule

 

[Kyle H]

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get out your camera and make a video of the noise, and at different angles around the suspected source. dont worry yet, may be simple.

 

[Kyle H]

I didnt make a video from under only because I drained the oil yesterday and I was told to refrain from running the engine until I learned whether or not it was gonna destroy the block.

I took these when I first got it. Also it may help to know I have a 1996 ext cab silverado for parts with a good 305 vortec. I am trying to maybe avoid pulling and swapping the motor until I need to.

 

[Hobie]

The squeaking in the second video tells me a rod bearing has spun. Small block chevys are bad about 7/8 rod spinning in higher mileage engines, especially if they are ran hard, poor service intervals, or have low oil pressure. Itll need a rebuild, or replaced

 

[Jcauli82]

Hey, just a thought, as I'm not an expert but speaking from a personal experience of mine with my 98 k1500 5.7 ecsb:. I had similar "knocking " sounds coming from what I thought was my motor when I first got my truck a couple years ago. Looked high and low listen to all around did all sorts of stuff trying to pinpoint the source of the noise, and come to find out one day when my starter went out on me that it was the Bendix of the starter being bounced around inside the starter housing. So I changed my starter and no more of that very similar sounding noise from my truck. But like I said just a thought take from it what you will and hopefully it helps out.

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[Redneckgeriatric]

could be rod, but on my speakers, it is too sharp a noise for a rod. a rod is constant, that noise is not. there are too noises, the lighter noise may sound like wristpin, if cylinder is missing, then wristpin noise can come and go, pull plug wire from cylinder and see if noise dissapears. holler back.

when you drained oil, did it have shiny thingys in it? oil filter have sparkles ?

when i was young, i bought a buick that had a rod knock according to two mechanics. paid $50 iirc. crawled under as it was running and found noise coming from flywheel shield. it was bent and flexplate weight was hitting as it came around. beat it out and gave car to my brother. you win some, ya lose some.

good luck, dont give up till you see the actual damage.

 

[454cid]

I could not see the tensioner moving much. Mine moves a little.... it works fine, and makes no noise.

I couldn't see the crank pulley at all.

 

[Junior_357]

The tensioner is supposed to move a little...but it does sound like the bearing is going in the tensioner pulley and/or idler pulley. Mine made a similar noise until I replaced those 2 parts.

But I don't think that is all the noise. I do agree with the previous post about the ticking being too intermittent to be a rod...

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