User Panel
User Panel
User Panel
GA, USA
|
Posted: 3/23/2024 10:22:33 AM EDT
[Last Edit: giantpune]
I done broke something in my little farm truck. Engine is a chevy 350, about 7 years old, fairly low miles. I had to get hard on the brakes and then hard on the gas to avoid a wreck. I guess I flogged on her a little too hard, and immediately after, she was running rough and making a noise. It made it home under its own power, and can drive around in the yard. When its idling, it will idle fine, and then drop down a bit and stumble for a few seconds, and then idle fine again.
Clunky rattle sound sounded like it was coming from the bell housing area. I pulled the cover off and disconnected the torque converter from the flex plate. It kinda sounded to me like a broken flexplate. Before I go pulling the transmission out, does anybody recognize this sound? Apologies for the audio quality. The exhaust is loud in the shop. 2 videos stitched together.  Chevy 350 noise |
|
|
|
Posted: 3/23/2024 10:54:24 AM EDT
[Last Edit: ske714]
[#1]
I see why you went for the flex plate. I assume the converter is pushed back enough for the studs to clear? Maybe a timing chain tensioner failed? That would also explain the idle issue.
I can't imagine the flex plate would make noise just spinning without the converter. |
|
|
|
|
Posted: 3/23/2024 11:16:51 AM EDT
[#2]
Flex plate is my guess. Or perhaps something hung up in the starter housing. You should be able to push the converter back and get a long box end wrench up in there to remove the crank bolts. Might need to loosen trans bolts and avoid a trans R&R.
|
|
|
|
|
Posted: 3/23/2024 11:19:01 AM EDT
[#3]
The starter gear isn't rubbing the flex plate teeth, is it?
|
|
|
|
GA, USA
|
Posted: 3/23/2024 11:34:58 AM EDT
[#4]
Quote HistoryOriginally Posted By ske714: I see why you went for the flex plate. I assume the converter is pushed back enough for the studs to clear? Maybe a timing chain tensioner failed? That would also explain the idle issue. I can't imagine the flex plate would make noise just spinning without the converter. Quote HistoryOriginally Posted By ske714: I see why you went for the flex plate. I assume the converter is pushed back enough for the studs to clear? Maybe a timing chain tensioner failed? That would also explain the idle issue. I can't imagine the flex plate would make noise just spinning without the converter. AFAIK, this engine does not have timing tensioners. Flexplate was held to the converter with bolts. I pulled the bolts out and pushed the converter into the transmission to separate it from the motor. It does get closer on its own, I think from the vibration of the engine running. Originally Posted By ske714: The starter gear isn't rubbing the flex plate teeth, is it? Nope. The starter is sitting dangerously close to the flexplate. I did not see any shiny spots that looked like they had been kissing each other. Originally Posted By dIIshoots: Flex plate is my guess. Or perhaps something hung up in the starter housing. You should be able to push the converter back and get a long box end wrench up in there to remove the crank bolts. Might need to loosen trans bolts and avoid a trans R&R. Are you suggesting replacing the flexplate with the transmission still in the truck? Loosen the transmission bolts to allow the transmission and engine to separate, remove the flexplate bolts, and swap the flex plate? I like the idea of that. Not sure if I'd be able to get my hand up in there to get the new flexplate bolts in. Maybe if I replace the bellhousing bolts with longer ones as I go, it will slide back further while still staying bolted up. |
|
|
|
Posted: 3/23/2024 12:15:50 PM EDT
[#5]
|
|
|
|
CO, USA
|
Posted: 3/23/2024 4:47:40 PM EDT
[#6]
At 28 seconds, you can see it flopping around.
|
|
|
WI, USA
|
Posted: 3/23/2024 4:58:09 PM EDT
[#7]
If you would hold the damned camera still LOL there is a point in there where you can see the flex plate flopping around in there. Shut it off and just grab the flex plate I bet you can make it squeak and crack.
|
|
|
|
Posted: 3/24/2024 3:34:11 AM EDT
[#8]
Quote HistoryOriginally Posted By giantpune: AFAIK, this engine does not have timing tensioners. Flexplate was held to the converter with bolts. I pulled the bolts out and pushed the converter into the transmission to separate it from the motor. It does get closer on its own, I think from the vibration of the engine running. Nope. The starter is sitting dangerously close to the flexplate. I did not see any shiny spots that looked like they had been kissing each other. Are you suggesting replacing the flexplate with the transmission still in the truck? Loosen the transmission bolts to allow the transmission and engine to separate, remove the flexplate bolts, and swap the flex plate? I like the idea of that. Not sure if I'd be able to get my hand up in there to get the new flexplate bolts in. Maybe if I replace the bellhousing bolts with longer ones as I go, it will slide back further while still staying bolted up. That is correct. It has been done without even removing the driveshaft or cooler lines. Not much room in between and you may need a long box end wrench but I have done it. GM never gave us the flat rate time to R&R the trans and make any money so a couple craftsman wrenches welded together worked. Marking the old flex plate at 6 oclock and aligning the new plate helps with the install. |
|
|
|
GA, USA
|
Posted: 3/24/2024 7:15:19 PM EDT
[#9]
Slight update. I was giving the motor a little once over. Figured it wouldn't hurt to double check the basics like air/fuel/spark/oil/timing/vacuum.
Front driver spark plug looks like its seen better days. The gap is smashed closed and the porcelain is shattered and gone. I tossed a new set in and she fires up and kinda runs. I went ahead and ordered a borescope to take a peek in the hole to try and get some sort of idea what's happening up in there.  
|
|
|
|
Posted: 3/24/2024 8:10:58 PM EDT
[#10]
You got a rod bearing hammered out.
|
|
|
|
GA, USA
|
Posted: 3/24/2024 8:47:20 PM EDT
[Last Edit: giantpune]
[#11]
Quote HistoryOriginally Posted By paul463: You got a rod bearing hammered out. When my borescope comes in, I reckon I can stick it up in the drain plug hole and peek around. Good news I guess is it looks like there's tons of room between the motor and cross member. The pan should be able to be removed and the rod bearing replaced with the engine still right where its at. That is, assuming the crank isn't toast. |
|
|
|
Posted: 3/24/2024 8:58:25 PM EDT
[#12]
I had one that made the same sound, it was the starter motor. When I pulled it out the pinion would fall outward if you tipped the started motor up and fall in if you tipped it down. It was bouncing off the flywheel teeth.
|
|
|
|
TN, USA
|
Posted: 3/25/2024 3:40:51 AM EDT
[#13]
Spark plugs don't just get smashed. Either someone dropped it when installed and said fuck it or you've got a serious issue. There really is no in-between.
|
|
|
|
Posted: 3/25/2024 6:34:24 AM EDT
[#14]
That sounds like a valve train issue to me.
|
|
|
|
|
Posted: 3/25/2024 9:37:33 AM EDT
[#15]
As mentioned, sparkplugs don’t ‘just’ look like that. I suspect there are some interesting issues with this motor in your immediate future. Best just suck it up and plan on a full R&R now. Or just source a replacement motor. Not like that’s a rare engine.
|
|
|
|
GA, USA
|
Posted: 3/25/2024 5:15:55 PM EDT
[#16]
My borescope came in today. I took a peek in that cylinder that had the smashed plug. There's definitely something hanging out in there that's not supposed to be.
Top of the piston is beat up. Cylinder wall looks pretty good,except I see a couple scratches. Aside from being clobbered, the top of the piston looks good, and clean. And that chunk of foreign whatever almost looks like a hex shape. Like a bit from a screwdriver. Except, I don't use those types of screwdrivers, so no clue how it would have gotten in there. Link to album with a bunch of pictures and a couple videos from the borescope. https://photos.app.goo.gl/2KsJeVQiQY7DDcFW8 Here's a couple highlights to save you the clicking.   
|
|
|
|
Posted: 3/25/2024 6:25:54 PM EDT
[#17]
Quote HistoryOriginally Posted By giantpune: My borescope came in today. I took a peek in that cylinder that had the smashed plug. There's definitely something hanging out in there that's not supposed to be. Top of the piston is beat up. Cylinder wall looks pretty good,except I see a couple scratches. Aside from being clobbered, the top of the piston looks good, and clean. And that chunk of foreign whatever almost looks like a hex shape. Like a bit from a screwdriver. Except, I don't use those types of screwdrivers, so no clue how it would have gotten in there. Link to album with a bunch of pictures and a couple videos from the borescope. https://photos.app.goo.gl/2KsJeVQiQY7DDcFW8 Here's a couple highlights to save you the clicking. https://iili.io/JjdILxa.png https://iili.io/JjdIZiv.png https://iili.io/JjdIQWJ.png Yeah, that sucks. The oil on the cylinder wall is not a good sign either. |
|
|
|
GA, USA
|
Posted: 3/25/2024 6:45:20 PM EDT
[#18]
Quote HistoryOriginally Posted By ske714: Yeah, that sucks. The oil on the cylinder wall is not a good sign either. I just did a leakdown test. @ 90psi, its losing 22psi. I feel it coming out the dipstick and the breather on the valve cover. |
|
|
WI, USA
|
Posted: 3/25/2024 9:19:51 PM EDT
[#19]
May as well just pull it and get it over with at this point.
|
|
|
|
Posted: 3/26/2024 1:58:59 AM EDT
[#20]
LS swap.
4.8 or 5.3, either one will get you rolling for $600, and outlast the rest if the truck. |
|
|
|
TN, USA
|
Posted: 3/26/2024 9:06:37 PM EDT
[#21]
Quote HistoryOriginally Posted By Positronic: LS swap. 4.8 or 5.3, either one will get you rolling for $600, and outlast the rest if the truck. |
|
|
GA, USA
|
Posted: 3/27/2024 7:23:55 AM EDT
[#22]
Quote HistoryOriginally Posted By Spaceboy: If you can do $600 LS swaps I'll fill your shop, lol. Yeah, LS swap bro math is worse than girl math. But anyways, lets not poop this thread up with that same discussion just yet. I'm not anti-LS. I would rather fix what I have here. If the motor is coming apart, maybe some small upgrades like a cam and pistons. |
|
|
TN, USA
|
Posted: 3/27/2024 9:33:25 AM EDT
[#23]
Quote HistoryOriginally Posted By giantpune: Yeah, LS swap bro math is worse than girl math. But anyways, lets not poop this thread up with that same discussion just yet. I'm not anti-LS. I would rather fix what I have here. If the motor is coming apart, maybe some small upgrades like a cam and pistons.  My Camaro was expensive for just an LS1 swap. LS1/T56 drop out 5k Cam kit $700 Headers $1k Exhaust $1k Driveshaft $450 Tuning $900 (300mail then 600 dyno once running) Optional stuff that came later Heads $2500 Used injectors $100 Retune $400 Nine inch $2200 And that is with me doing everything but tuning. I even built the wiring harness. |
|
|
GA, USA
|
Posted: 3/27/2024 11:43:31 AM EDT
[#24]
Quote HistoryOriginally Posted By Spaceboy: Right My Camaro was expensive for just an LS1 swap. LS1/T56 drop out 5k Cam kit $700 Headers $1k Exhaust $1k Driveshaft $450 Tuning $900 (300mail then 600 dyno once running) Optional stuff that came later Heads $2500 Used injectors $100 Retune $400 Nine inch $2200 And that is with me doing everything but tuning. I even built the wiring harness. I'm still weighing my options on this one. Motor is definitely coming out of the truck. I am leaning towards LS1/vortec iron heads and intake on my existing block. That will be the closest to an LS swap this will become. This is not a racecar. I have lots of other old cars for that. This truck putts around town and pulls stuff like dingos, lawnmowers, and trailers full of dirt. However I build this motor, I will be caring about torque at 2-3k rpm rather than HP at 7000rpm. |
|
|
TN, USA
|
Posted: 3/27/2024 3:44:28 PM EDT
[#25]
Quote HistoryOriginally Posted By giantpune: I'm still weighing my options on this one. Motor is definitely coming out of the truck. I am leaning towards LS1/vortec iron heads and intake on my existing block. That will be the closest to an LS swap this will become. This is not a racecar. I have lots of other old cars for that. This truck putts around town and pulls stuff like dingos, lawnmowers, and trailers full of dirt. However I build this motor, I will be caring about torque at 2-3k rpm rather than HP at 7000rpm. Vortec heads with rebuild $6-700 Intake to match heads $3-400 Springs if you change cam $150 Vs this example here: Brodix heads complete $1267.99 |
|
|
GA, USA
|
Posted: 3/30/2024 9:14:53 PM EDT
[#26]
I got the motor out today and am back with answers. For everybody who guessed a broken flexplate, including myself, you were wrong. I did see some new shiny chamfers on some of the teeth. Perhaps the flexplate warped and part of it was hitting on the starter.
To get the mystery chunk of metal out of cylinder #1, I oriented the motor so the spare plug hole was down. Then rotated the crank so #1's exhaust port was open. And then blew air in #1 exhaust port with a shop vac. The chunk blew out onto the ground. Now that I see the size of it, it does not look like the tip of a screwdriver. Next, I pulled the oil pan off. There was a similar chunk of metal in the pan. As I was dumping the last of the oil out, there were silver streaks in it. And then looking up at the bottom of piston 1, it is clearly broken. My guess is it was a chunk of piston that I got out of the spark plug hole, more chunks of piston in the pan. And god only knows what all the silver streaks in the oil are. Maybe some little chunk got sucked up into the oil pump and circulated throughout the engine? I'm thinking she's getting torn down and gone through. Maybe put back together with a couple upgrades.     
|
|
|
|
Posted: 3/31/2024 4:34:29 PM EDT
[#27]
Dang that is one ugly flexplate.
|
|
|
|
|
Posted: 4/1/2024 12:11:13 PM EDT
[#28]
That sucks.
I wish I would have commented earlier - that sounded 100% like a rod or bearing noise, but everyone was on the flex plate so I thought meh. |
|
|
|
|
Posted: 4/1/2024 1:22:36 PM EDT
[#29]
383 build, afr heads, longtube headers, cam.
|
|
|
|
GA, USA
|
Posted: 4/1/2024 1:49:39 PM EDT
[Last Edit: giantpune]
[#30]
Quote HistoryOriginally Posted By Furyataurus: 383 build, afr heads, longtube headers, cam. Already has the long tube headers. This is the gm performance 290HP crate engine. I looked up the specs on it, and it appears to have the same hydraulic flat tappet cam from the L-82 corvette motors from the late 1970s and early 1980s. Paperwork says '.450" intake / .460" exhaust. Camshaft duration (@.050") is 222 degrees intake and exhaust. Lobe centerlineis 114 degrees' Heads are some lackluster 76cc cast iron 624 castings. Combined with the current pistons, 8.5 compression My current plan is to just hone the cylinders and swap in a set of H631CP flat top pistons. And swap the heads out for some 64cc ones. Combined with a 0.028" head gasket (10105117), Should put me at 9.96:1 static compression. Somewhere north of 300HP and still running on cheap gas. That's all this little truck needs. Probably not gonna go full retard with a stroker kit. Unless I start tearing it apart and the crank is busted, too. I think I looked at the AFR heads and only saw the ones setup for roller cams. I did see trickflow and summit had some setup for flat tappet, or sold as bare. And there's some other cheap chinese ones. But the internet is full of examples of those that have piss poor valve jobs right out of the box. Was thinking maybe pony up for nicer heads and not have to do a valve job on a brand new set of heads? |
|
|
GA, USA
|
Posted: 4/4/2024 9:54:20 PM EDT
[#31]
I got the valve train and heads off the motor today and a couple of the pistons out. A few of the other cylinders had little chunks of debris similar to what was in #1. And there was similar damage to the tops of the pistons, but nowhere near as bad as what was in #1. I'm still on the lookout for whatever that is that broke off.
There's only so many ways for crap to get down into the pistons. I reckon I'll try and see if the chunks are magnetic next. Up stream from this, there was an aluminum intake, a carb spacer, the edelbrock carb, and a stamped metal air cleaner. So far, the cylinder walls all look like they'l clean up with a home hone job. And the crank journals and rod bearings all look mint. |
|
|
|
Posted: 4/4/2024 11:52:58 PM EDT
[Last Edit: JoseCuervo]
[#32]
IMHO, I wouldn't put any money into that engine.
There are many, cleaner, not fubared, blocks out there to start a rebuild with. Parts of several pistons banging around? Metal in the oil pan? Noises? You would spend more money chasing possible / likely problems than starting with a block from a wreck. That is not including the labor costs, or your time, to see what is, or may be, wrong. Cut your losses now- |
|
|
|
GA, USA
|
Posted: 4/5/2024 9:08:23 AM EDT
[#33]
Quote HistoryOriginally Posted By JoseCuervo: IMHO, I wouldn't put any money into that engine. There are many, cleaner, not fubared, blocks out there to start a rebuild with. Parts of several pistons banging around? Metal in the oil pan? Noises? You would spend more money chasing possible / likely problems than starting with a block from a wreck. That is not including the labor costs, or your time, to see what is, or may be, wrong. Cut your losses now- IDK about cleaner. Inside, this guy looks like it was put together last week. Zero sludge on the bottom end, top of the heads, or in the lifter valley. And all the different colors of paint pen visible on all the connecting rods and shit. A little wipe down and this guy will be clean enough to eat thanksgiving dinner off. As far as the chunks go, I tested them just now, and they stick to a magnet. So they are not chunks of these pistons, which are aluminum. I will continue the search to see if I can tell where they came from.    
|
|
|
|
Posted: 4/5/2024 4:29:23 PM EDT
[#34]
 That does not look right. |
|
|
|
|
Posted: 4/5/2024 7:02:25 PM EDT
[Last Edit: JoseCuervo]
[#35]
"Clean" was probably the wrong word for me to use, OP. I meant, not one with mysterious magnetic metal pieces in the cylinders and oil pan and not an engine that had regular oil changes and wasn't very dirty.
A crashed / or in a fire engine would put you hundreds of dollars ahead of what you have posted pictures of, in my opinion. |
|
|
|
CO, USA
|
Posted: 4/8/2024 6:09:33 PM EDT
[#36]
Take a good look at your valve guides, especially for that cylinder.
|
|
|
|
Posted: 4/8/2024 6:11:46 PM EDT
[#37]
Sounds like a piston let go.
|
|
|
|
GA, USA
|
Posted: 4/8/2024 6:50:45 PM EDT
[#38]
I got the engine torn down fairly well. Going by chevy's numbering, there was chunks and evidence of something hammering the top of pistons 1, 4, 6, and 7. The intake manifold is a dual plane, and those 4 cylinders all share the driver's side intake plane. That leads me to thinking something broke and made its way into that side of the intake.
Carburetor still looks good from every angle I can see. The power brake check valve is black plastic, and still functional. So I dont think anything got sucked in that way. PCV valve is metal, and as far as I can tell is still all proper, present, and accounted for. It rattles when you shake it. There are no other large things connected to vacuum. So still not sure what those are chunks of. I've got the piston assemblies out. Honed the cylinders with a drill. They look good enough for government work. Not perfect, not bad enough to make me want to send the block off to be bored. I'm gonna try my hand at a low buck back yard rebuild first and see where it gets me. If nothing else, it'll be some cheap american fun. |
|
|
|
Posted: 4/8/2024 7:44:36 PM EDT
[Last Edit: JoseCuervo]
[#39]
Good luck brother! I admire the enthusiasm. I hope it pays off as it may well, MANY, do. The catch can be a bitch though. Please keep us posted, this is one of the better, recent, AR15.com threads though. The daily life threads get a bit tiresome.   
|
|
|
|
GA, USA
|
Posted: 4/8/2024 8:34:29 PM EDT
[#40]
Quote HistoryOriginally Posted By paul463: You got a rod bearing hammered out. Quote HistoryOriginally Posted By paul463: You got a rod bearing hammered out. Originally Posted By Into_the_Void: That sucks. I wish I would have commented earlier - that sounded 100% like a rod or bearing noise, but everyone was on the flex plate so I thought meh. For you guys that guessed rod bearings, I think you were just as wrong as the broken flex plate crew. When I got the pistons and rods out, the bearings mostly looked pristine. There was just the slightest bit of visible wear on one of them. I'm gonna use a new set when I put it back together. Its only a few bucks. |
|
|
|
Posted: 4/9/2024 11:09:53 AM EDT
[#41]
Are all of your 10 mm sockets accounted for?
|
|
|
|
GA, USA
|
Posted: 4/9/2024 1:07:26 PM EDT
[#42]
Quote HistoryOriginally Posted By ske714: Are all of your 10 mm sockets accounted for? Luckily I lost those long ago. They had no chance of making it into this motor. |
|
|
GA, USA
|
Posted: 4/15/2024 7:16:37 PM EDT
[#43]
I ordered the stuff to get the bottom end back right. Pistons, rings, bearings, gaskets, and oil pump.
|
|
|
GA, USA
|
Posted: 4/20/2024 9:35:11 PM EDT
[#44]
On deck, I have a melling oil pump and pickup, flex plate, felpro gaskets, and a bunch of ARP bolts. Fingers crossed I'll get to light it off this week. If I'm lucky, the stock pushrods will be the right length and I wont have a bunch of down time ordering parts.      
|
|
|
GA, USA
|
Posted: 4/23/2024 4:25:04 PM EDT
[Last Edit: giantpune]
[#45]
I have a few things left to hook up on this cart and then I can try to fire it up. 
|
|
|
CO, USA
|
Posted: 4/23/2024 6:52:07 PM EDT
[#46]
Did you put sealant on the head bolts?
|
|
|
GA, USA
|
Posted: 4/23/2024 7:24:29 PM EDT
[Last Edit: giantpune]
[#47]
Quote HistoryOriginally Posted By number40Fan: Did you put sealant on the head bolts? Yep. Marshmallow fluff on all the head bolts and the rocker studs. Some of the paperwork said put it on the intake bolts, too. So I did. 
|
|
|
GA, USA
|
Posted: 4/25/2024 5:51:09 PM EDT
[Last Edit: giantpune]
[#48]
I got it back running this afternoon. Oil primer tool came in, and that unblocked me. I got the oil system primed, then dropped in the distributor and installed the plugs. Ran a wire to the coil, one to engine ground, and 2 wires to the starter. Then put some gas in it and it fired right up.
Cell phone potatocam video doesn't do it justice. It sounds like a V8 with open headers. I plan on hooking a radiator up to it, then getting a few heat cycles into it before dropping it back in the truck. The instructions for the heads and the intake both said to run it a few times, then retorque those. And I discovered that the new heads do not have a threaded hole for the temp sender like the factory heads. No problem, I'll just use the one in the intake. Except last night, I was not able to get the plug out of that hole. It is seized up. The big wrench and torch couldn't get it loose. I do have some threaded ports available sitting above the thermostat. I could get by using one of those for now. The temp gauge would be useless until the thermostat opened up. Second video is taken with a camcorder, with a bit better microphone than the cell phone.  Chevy 350 running on engine stand  Chevy 350 running on engine stand, 2 |
|
|
TN, USA
|
Posted: 4/25/2024 7:57:20 PM EDT
[#49]
Man you work quick, nice job
|
|
|
GA, USA
|
Posted: Yesterday 7:23:58 PM EDT
[#50]
Quote HistoryOriginally Posted By Spaceboy: Man you work quick, nice job Thanks. My limiting factors are the checking account and waiting for the delivery guy to bring my boxes of parts. Luckily I'm close to a summitracing warehouse so those orders show up in a couple days. My next order I'm waiting on is from LMCTruck. I got a couple odds and ends that I'm replacing as the motor goes back in the vehicle. |
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
Attached File
