Sorry for the noob style post. I am on forums all day but suck at mechanical diagnostics. I do body work and feel comfortable doing any mechanical work that needs to be done. I can also follow directions pretty dang well as long as they make since. SO ... recently I picked up an 89 s10 blazer in much need of body work but was able to drive it home ( about five miles). the guy I got it from had it sitting in his back yard for about 16 months and I had to drag it out of his back yard to his driveway due to it not wanting to start. The vehicle would run if we sprayed starter fluid into the TBI carb with the air filter off, so I figured bad gas and dropped the tank. Sure enough the gas was bad as it gets. I cleaned out the bad gas from the tank and cleaned the fuel filter out by spraying carb cleaner all up in it til the fluid was clear. I put everything back together and then to save myself some trouble only put about 6 dollars worth of gas in it to make sure that was the issue. the thing started right up and ran pretty strong in park while no load on the engine. I drove home about five miles and the blazer stalled on me twice during the trip both times taking a turn. I also noticed that the blazer lacked the power I know it should have almost like it was starving for fuel or air when I tried to accelerate. but i got it home easily enough. Ok so now the fun starts, I lifted the hood and really started to get to know my new toy and realized that the poor girl has seen a few better days. The carb was real dirty on the outside and there was oil buildup over most of the surface of the engine compartment. I pressure washed the engine bay and motor without applying degreaser or any other chemical just to see what was under all that gunk. And it turned out while weathered everything seemed to be in pretty good order. I sprayed carb cleaner on the carb's outer surface and then rinsed it off with warm water (while the air filter was still on by the way). I wanted to make sure there were no loose particles around it when I took off the carb. I then really cleaned out the carb with carb cleaner, a fine pick, tooth brush for scrubbing, and a handful of clean rags. I got it real good but noticed that a line leading to I believe the fuel vapor canister ( black cylinder on the front drivers side by the radiator ) was completely clogged with what turned out to be near atomized particles of the paper gasket underneath it. And I mean 100% clogged. Much batter now since it fell apart when I sprayed through the bottom of the carb. I also visually made sure no dirt remained in the carb at all. This also cleaned up real good.I checked the oils and it was about a quart low so I added one. checked again and it read full on the dipstick ten minutes later. I reassembled the carb and airbox and started up the blazer and it did not hesitate at all. So I drove it around my apartment complex about a half miles distance. parked it again and got the information off the filter to get a new one as I thought I would do an oil change so I can know it was done from day one of owning it. I noticed the oil was really black or more like the color of a coffee bean. I walked away from the truck for the night after that so I could plan my oil change. the next day I went to start the blazer and was hoping it would fire right up. I was excited when it did just that and I was thinking "SWEET ... The motor is strong and I only have body issues to correct!". The next day I started to takes notes on what parts I needed to find to bring the visual aspect of the blazer back to life and which ones I could repair or salvage. I started up the blazer again and this time I wanted to record the gauges to reference the oil gauge moving alot when I pressed the gas. I happened to catch the sound that started right then. I have already used the search thread and tried to identify it with other examples on this forum and think it is the connecting rod bearing on the first cylinder on the drivers side or the second one on the drivers side from the front. I think it's the number one and three cylinders. Sorry if that's not right. That's what I heard from the drivers seat with the window down. I am going to post the cell phone video I had so if someone could please either tell me I am right or correct me and guide me in the right direction please. the oil I put in was 5W-30, I pulled and checked the plugs and they are all clean actually, and gapped right, no oil leaks, serpentine belt is ok - will replace soon anyway, coolant appears to be full, anything else I can check if you need to know about it to help me out here. Here is the video link ///

 

Sounds more like a bolt on the flywheel hitting the bell housing.
If it were bottom end, rocker or a lifter I believe it would be more regular. I heard you rev the engine & it was ok for a few seconds before the 'hitting' sound came up, that's why I say that.

 

Really, I did not think about that one. Ok so help me out here a bolt is loose, broke, flywheel is warped, what would cause that to just happen all of the sudden. I am trying to learn all about this little truck and want to really know it in and out.

 

I agree unless its just poor video quality, but to me the sound is too sharp for it to be a bearing but it does sound a little like a lifter. I know with my truck shortly after i put different oil in than what was always put in it one of my lifters got stuck and made a horrible sound kinda like that but it went away.

Oh and dont use 5w 30 its to thin specially for an older engine. use 10w 30 or higher on these engines.

But again like Rotti said if the knocking doesnt exactly follow the RPM its probably a bolt which believe it or not is fairly common.

 

Man, I am glad I was video capturing stuff and got this noise on film so to say. If it is the flywheel I happen to have one in the truck right now. I should be able to drop the tranny and replace the flywheel pretty easily right? a few hours worth of work and tighten the bolts while i am at it. This does not mean my tranny is shot or something does it? and thanks for both your responses by the way

 

You should be able to remove the inspection plate underneath & shine a flash light up there & see if the flywheel is cracked, loose or a bolt sticking out. Also look for witness marks (scuffs, impacts etc) all around in there with an inspection mirror.
I've had my share & then some of internal engine pings, knocks, clanks etc & that sound in the video was not one of them.
Connecting rod bearings
Lifters
Push rods
Valves
Valve guides
Rocker arms...
& that sound you have isn't close to the ones I've heard with all the above.
Not saying it isn't, but I'd be surprised if it were one of them.

You could pull the valve covers, start it & listen with a stethoscope or something.
Another trick I use is to take a 2x2 of wood & push on the lifter side of the rocker while it's at idle. The wood is porous enough to absorb some impact & sound. If the sound goes away, you've found the area of the issue.
Could be a push rod or lifter or the rocker needs adjusting.

 

Ok, so i was able to get the inspection plate off and had my upstairs neighbor help me turn the crank shaft with a socket wrench while i inspected the flywheel. it felt snug at every inch and the only markings i saw were from me hitting the flywheel with the inspection plate when I took it out. those marking were on the inspection plate. I then started the blazer and tried to listen to where the sound was coming from and both my neighbor and I agreed it was was coming from the drivers side of the engine but its hard to say if it is top or bottom. so I took the valve cover off on the drivers side and wiggled the lifters with my fingers and four of them were pretty loose. I tightened them just until i could not longer wiggle them with my fingers ( i know they need to be tightened properly with a torque wrench but i did not have one handy). I then tried to start the engine and it was hard to start but I got it running for about twenty seconds and the noise was still there but it was very intermittent and random. the truck stalled and after that I could not get it to start again. I tired pulling the number 1 spark plug with the engine running to see if the noise stopped but it did not. I took my mechanics stethoscope and listened to the motor before tightening the lifters both on the transmission and the oil pan. the oil pan gave off way more of knock then the transmission. I took the stethoscope and listened on the valve cover and that is why I pulled the number one spark plug boot from that plug to try to stop the noise. tightening the lifters seemed to get rid of the noise some but it came back after about ten seconds. I am going to pull the valve cover off again tomorrow and see if any of the lifters are loose again. I also want to loosen them some again so the motor starts easily again. I dont have the equipment to pull the motor so I would have to check the conrod bearings but pulling the axle and dropping the oil pan.

 

OMG Don't do that to the rockers, please! Sure some of them are going to be loose because the cylinder is at TDC. You can bend pushrods, valves, valve guides. Here's the proper procedure for adjusting them.

HYDRAULIC LIFTER CAMSHAFTS
When the exhaust valve just begins to open on the #1 cylinder, adjust the #1 intake valve by loosening the adjusting nut slightly while spinning the pushrod until you feel lash in the rocker arm. Tighten the adjusting nut until the slack is taken out of the rocker arm and pushrod. Lightly turn the pushrod with your fingers as you tighten the adjusting nut, and you should feel a point where there is a little resistance. This is called zero lash – the point where you have taken all of the excess slack out of the pushrod. Turn the adjusting nut ½ turn past this point, giving you optimal pre-load for the rocker arm, pushrod and lifter. Follow this procedure by carefully adjusting each intake valve according to cylinder firing order.
Next, we’ll adjust the exhaust valves. To do so, you need to turn the engine over until the intake pushrod moves all the way up. Rotate just past maximum lift, where the intake will begin to close. The lifter is now at the base circle, and the exhaust valve can be adjusted. Note: DO NOT go too far down (over halfway) past the point of maximum lift. If you go too far, you will be in the overlap cycle – where intake valve lash is being taken up as the exhaust valve begins to open.
Rotate the exhaust pushrod with your fingers and begin to tighten the exhaust adjusting nut. When you begin to feel resistance against the pushrod, you are once again at zero lash. Tighten the adjusting nut another ½ turn. DO NOT OVERTIGHTEN. Repeat through the firing order until the lash on every exhaust valve has been set.
Now it’s time to double check, starting with cylinder #1. When the exhaust begins to open, check the intake. New hydraulic lifters shouldn’t be pumped up yet, so you should be able to spin the pushrod with some resistance. Think of the hydraulic lifter as a shock absorber – and you want to be right there in the middle of it. Until you have oil pressure, you’ll be able to push the lifter plunger into the bottom of the lifter. At that point, the lifter becomes solid. It might help to mark each rocker that has been set and then mark again each one that has been checked, giving the ones that are 100% finished a big “X” on the rocker arm body.

 

I went back out there and pulled the valve cover off. I backed the the nut off of each lifter i tightened the same amount in reverse. I take pretty good notes when I do stuff. I then started the blazer and it fired right up with no hesitation. so with that issue averted, I videoed the knock again two different times and panned the camera around the motor to try and isolate the issue and took my stethoscope to several areas til i felt i heard the noise the loudest. it is definitely coming from the number 1 cylinder area. The hard part is that it sounds like its coming from the middle area between the top and the bottom. I have questions so try and answer these for me please.

1.) Is it possible there is just some debris is in the cylinder?
2.) could I have dislodged something since this vehicle sat for 16 months?
3.) would an oil change maybe fix this?
4.) what abut seafoam, could that correct this issue?
5.)Whats my next step?

Man I am afraid just starting this thing repeatedly is causing more damage. I hope not though.

 

After it sitting 16 months the bearings, cylender walls & lifters will be as dry as a popcorn fart.
You should have disconnected the coil from the distributor, pulled the fuel pump fuse & spark plugs, changed the oil & cranked it over for 20 seconds. Not much longer at a time or you could overheat/burn out the starter. Do that once a min for 5 mins to pump up the lifters. A battery charger on it so it spins fast isn't a bad idea either.
But anyway... I would not do a seafoam treatment until it's ran a few hundred miles. Let the new oil circulate!
There might be carbon that dropped into a cylender but it's doubtfull & wouldn't make that high pitched, metal on metal sound IMO.
I still think it sounds like something hitting the bell housing, maybe a bolt from the flywheel or torque converter. If that IS bottom end, using the word "bearings" isn't needed because they aren't there anymore.
Try removing the oil pan drain plug & look for metal shavings on the magnet. Just hold your thumb over the hole when you remove the plug. If it does have shavings, hand it to a friend or whomever to wioe it clean.
I think the dry start caused issues with everything being dry.