The Engine Sound You Never Want to Hear

what do you do when your engine is making a terrible knocking sound is this rod knock or is it some other noise then how do you figure it out well that's what we're going to do today because luckily my rb is making an awful racket so we're going to take this opportunity to take a dive into this engine to diagnose a knocking sound it's going to make me cry potentially i'm zach and this is money bit baby rip this thing open thanks to car insurance comparison site the zebra for sponsoring this video this is what a complete waste of time and money looks like [Music] don't be like us save time and money on your car insurance with the zebra the zebra could save you up to 670 a year insuring your car insurance isn't a money pit i get it they compare quotes from top companies side by side so you can find the coverage and price that you want all that means is more moolah in your pocket for whatever you want best of all there's no spam calls or techy jargon it's just unbiased independent advice you can always trust to steer you in the right direction now job why don't you take us in the right direction we wasted all our money on this ad don't be like us save some money by comparing car insurance rates just go to the zebra.com slash money pit to see how much you can save [Music] so a few months ago right around thanksgiving i had this car out in the mountains i was ripping around and it felt great it was making good power i had a huge smile on my face making all the good noises i ended up next to like a mountain basically and i could hear some knocking bouncing off the mountain back into my ears and i thought oh my god i think that's my car so i pulled over as soon as i could hopped out listened to it real quick listened to it for long enough to realize oh that's that's a problem that sounds like some real catastrophic issues i do think that the noise is coming from the bottom end of the engine the rotating assembly basically the crank connecting rods pistons that sort of end of the engine but the question is how do you figure out where the noise is coming from what part of your engine is making the noise well the first thing we need to do unfortunately is listen to it so i'm going to fire this thing up and we're going to listen to it knock just so you guys can kind of catalog what this sound is and then when we figure out what exactly is making the noise we'll know what that sound is correlated to so i guess it's time to start this thing up okay all right that's enough that's enough that's enough well uh that's the first time i've started the car since the day that this happened and it sounds just about as bad as i remember uh so now we gotta figure out where that sound is coming from but before we can do that let's kind of talk about the options or the possibilities for where that noise could be coming from to do that let's go look at the spare miata engine that i got over there so one of the first options is what's called piston slap and that is pretty much what it sounds like it's the piston slapping around in the cylinder bore and smacking into the sides of the walls basically it happens if there's too much clearance in between the piston and the wall of the cylinder that can happen due to wear or due to being put together poorly or machined poorly or all sorts of reasons but the fact is if it is happening it can do a lot of damage and cause a lot of wear to your pistons and your block so that's uh that's basically what piston slap is to check for that you kind of got to get your eyeballs into the cylinders and ideally onto the sides of the pistons i have a bore scope that will be able to stick down the spark plug holes and look around and see if there's any damage moving right along let's flip this engine over and get the oil pan off of it [Music] [Music] okay now let's talk about one of our other options for where this noise could be coming from one of the most famous options broad knock or rodney knock as he's known where i'm from so first let's talk about what rod knock even is first off well we got to understand the connection between our crankshaft and our connecting rods basically your crankshaft is connected to your pistons by the connecting rods and your connecting rods are connected to your crankshaft by way of a bearing so the clearance in your connecting rod bearing should be very small a couple thousandths of an inch basically just enough clearance for a thin film of oil to separate all the parts and keep things moving nice and freely now if that clearance isn't big enough or is too big well the oil can't do its job and you end up getting a bunch of wear and you end up with a bunch of excessive clearance because of all that wear and then you end up with rod knock so one way to test for rod knock is to take your oil pan off and wiggle all your connecting rod bearings now all these feel pretty tight there's always going to be a little bit of side to side play here so that's okay but in this direction none of these feel loose which this is not an engine that was supposed to have rod knock so that makes sense okay so there's our rod cap looks like bearing stayed behind okay so and our bearing was left down here so this looks fine i mean there is some wear but this is this is a pretty standard looking bearing i mean i'm sure if we take all these caps off they're all going to look pretty much the same let's do it i'm actually kind of interested just on a side note to see what the bearings look like in this engine so i'm going to take them off basically same deal got a little bit of wear going on down there oh and here's a good look at how these things get oiled so you've got your big oiling hole in the rod journal here and that's where oil is forced through to you know create that thin film of oil that everything rides on so the oil comes from the oil pump and eventually out these holes in your crankshaft to force that oil pressure into these bearings and keep things happy and healthy so oil pressure is obviously super important to keeping your engine happy and healthy and the thing that really in a lot of ways determines oil pressure is your bearing clearance so depending on this clearance you'll have different oil pressures if this clearance is very tight then you're going to have well you're generally going to have really good oil pressure because not as much oil can escape these holes right but if this tolerance is really loose well more oil can fall out this hole into your bearings and you know down back into your sump so you'll have lower oil pressure now i bring that up because it's also kind of a decent way to know if you've got a rod knock issue you can see i mean this thing is supposed to stay like this it's supposed to be dropped in this tang locates it you bolt it in place and it should never spin the bearing should stay still but if your tolerance is too tight or too big or you've got improper lubrication for any reason and your crankshaft actually makes metal to metal contact with your bearings it can spin them now if it does spin the bearings well then you've obviously got problems right that's going to cause rod knock you know maybe the bearings will double up on one side and one side will have no bearings and then basically you've got a huge gap on one side of your rod journal so that not only creates the noise because that gap that you now have lets your crankshaft smash into your connecting rod making that deep knocking sound but another thing that happens there is that your oil pressure will drop because since you've completely removed a bearing from where it should be it's no longer helping to control oil pressure so if you spin a bearing it can be because you lost oil pressure or you can lose oil pressure because you spun a bearing now the 240 still has fantastic oil pressure 100 psi at startup so i don't really think it's a bearing or at least a spun bearing for that reason but it could be though i don't think so but it could be but i don't think so but it could be without further ado uh now that i've kind of laid out some of the options some of the possibilities for these knocking noises let's dig into the 240 and try to figure out where my knocking noise is coming from all right so it's great to understand the potential possibilities of where this knocking sound could be coming from but actually finding it is a little bit of a different story the fact is you really got to get in there and see the issue with your eyes to know what it is so that's what we're going to do and uh we're going to try to do this in uh in an order that makes sense you know try to go from easiest to hardest so the first thing i'm going to do is real simple i'm just going to check to make sure this thing is still in time uh when i just started it and we were listening to the noise i noticed that my timing belt is pretty loose that could potentially mean that this is a valve train issue uh i don't think that's the case but it's incredibly easy to check to do that i just got a socket that i'm going to stick on my crank pulley here and i'm going to turn it until our top dead center mark on the crank lines up with our top dead center mark on the timing cover and then our timing marks on our cam gears should also line up with our timing marks on our timing cover so just going to spin this thing till we get to top dead center all right so now that i have this all lined up and i've got my crank pulley at tdc we can check our timing marks and once we check them we can see that we are in time so we haven't jumped time that is good news uh we still have a super loose timing belt so that's gonna need address but uh that's no big deal the next easiest thing to do is gonna be to pull the spark plugs out and gander down into our holes okay so i've been pulling out the spark plugs pulling out the last one right now and obviously as i pull them out i've been inspecting them to make sure that they don't look awful or like there's any signs of damage or anything like that maybe a little dark like running a little rich but they look fine really so problem doesn't lie with these but now that we've got all the spark plugs out of the way we can look down into the cylinders this is my borescope i'm actually ogling over it this is the first time i've used this one so this just sends out a wi-fi signal and then sends the signal right to my phone so it's really simple it's just this and my phone an app you download so it's a really handy tool to have around and it should make poking around these cylinders a lot easier so let's uh let's go jam this down in my holes i'm going to turn the crank so that whatever cylinder we're working in the piston is at bottom dead center so we can see everything and basically i'm just going to look around look for any signs of damage look for anything that looks out of place look for any blown holes in the sides of anything yeah i mean really that's it we're just looking for anything that looks bad so let's look okay so right here i can see a little bit of wear you can kind of see some striping but that doesn't look very bad that's certainly not enough to make any noise and you can see cross hatching and i can still see some vertical wear which isn't great but it doesn't look terrible so i'm going to keep doing this through all the cylinders i'm going to just be looking around keeping my eyes peeled for any damage and if i find anything you'll be the first to know [Music] all right doc give it to me straight well we've definitely got some wear it uh it doesn't look great okay so after sticking the camera in all my cylinders we've got visible wear in pretty much all the cylinders concerningly visible wear in at least two of them so that alone is enough for me to take this thing out and rebuild it but we're gonna keep poking around uh we're gonna take the oil pan off and see if there's anything weird going on down there okay so now we got the car up in the air uh so now i'm gonna drain the oil and we're gonna take a look at the oil as it comes out see if there's any chunks of metal in it i do see some reflection in the oil like some little tiny pieces of glitter uh not what you want because those are usually pieces of uh your engine all right so now that we've got all the oil out of the pan i'm just going to take the pan off so we can get a look at what's going on inside of there so close okay so to get the oil pan out i need more room in between the bottom of the engine and the subframe so i'm gonna support the engine with a support bar and then i'm gonna disconnect the engine from the engine mounts and then i can either raise the engine up with this bar by cranking up that handle or i can lower the subframe you just have to disconnect the stuff that connects the subframe to the car so when i bring down the subframe i'm also going to bring down the front suspension brakes so i have to disconnect the coilovers from the strut towers and then we're ready to loosen the subframe hardware and drop this puppy down [Music] and now the subframe should move and the engine should stay still [Music] okay okay now before we can go toying around i'm gonna put this uh subframe back up okay now that that is safely suspended first let's look in the oil pan and see if there's any junk or debris in there and then we'll uh poke around in there it doesn't feel nice in there well those little gold pieces that looks like bearing bits to me [Music] oh it's okay it's just an engine it's just engine parts well the news is not good all right well so we definitely have some uh what looks like bearing particles in our oil pan so let's go uh touch the bearing spots let's go see if we've got any loose connecting rods and figure out what the hell we're gonna do [Music] now what we're gonna do is uh basically just kind of try to wiggle the bottoms of all of our connecting rods and see if any of them have apparent play and they might not i might not be able to to get too much play out of them uh so probably ultimately take the caps off but first i'm going to do is just spin it around give all these a good wiggle r2 feels i was three feels alright oh yeah i couldn't see it four feels alright okay no five feels okay oh baby and it is lucky number six you see it nice and silvery yeah good that's how they all look and like how they should and number six comes around you can see a little hot spot looks like we had some heat going on on the inside of that thing there so i'm gonna guess that that's where my bearing issue is so i'm gonna pop that puppy off and take a gander there she comes are the bearing that high up yep and the other one's halfway down and around the other way and i can see a chunk of gold flake coming got oil in my ear that's what i get well wow that's not how she's supposed to be uh bearing seems to have spun so number six uh is our problem you can see a hot spot you can see where on the back side of the bearing bearing is supposed to stay still in the connecting rod uh and the crank is supposed to spin in it not not any of this type action and you can see we've got some of that going on so i think we found our smoking gun number six was making the noises uh and also we've got some pretty concerning cylinder wear that i found in all of the holes so yeah we got to take the engine out we got to take it all apart we got to take inventory take stock of what kind of shape everything's in then we need to order some new parts find a machine shop probably and then put it all back together no big deal uh yeah no big deal we have the tools it's just car parts um it's very sad i'm crying on the inside but it's going to be okay we can rebuild it we can make it better on that note i guess we've got a few more episodes to make so thank you guys for checking this one out i hope you had a good time i had a terrible time so please subscribe to the channel to make it all worth it and follow me on instagram zackjob and follow donut donutmedia and i'll see you guys next week goodbye turbos are awesome but they don't even have a mascot which is downright not awesome so we decided to take matters into our own hands and give turbos the representation that they deserve introducing spinning the official unofficial mascots of turbos and the people who love them is a sentient turbocharger 100 dedicated to providing power to anyone who needs him he's cute but he's dangerous just like us oh that's where i put this thing to commemorate the birth of our beautiful new friend we put him on a shirt it's stew stew stupid soft and stew comfortable congratulations little guy it took nolan two years to get his own shirt [Music] right now spinney boy is the official unofficial mascot of turbos and the people who love them but i honestly believe if we work together we can make him the official official mascot of turbos and turbo enthusiasts we've done this before guys remember about forces that didn't mean anything before we can do it again let's ride if you can get a shirt to show your support and your love for spinning boys and if you don't buy a shirt i don't really care post a picture of your own turbo with hashtag spinning board i want to make him a star i love this little guy if you want a shirt you can get him at donutmedia.com i love you now back to the show [Music] what's that here to help and bring you joy watch our world is spinning boy

Channel: Donut

Views: 2,229,226

Keywords: DonutMedia, MoneyPit, DIY, Nissan, S14, Nissan S14, Nissan Skyline, RB25 Engine, Engine Swap, Rod Knock, Engine Sound, Dead Engine

Id: 2YPLzOgWUV8

Length: 19min 41sec (1181 seconds)

Published: Wed Mar 24 2021