Honda Accord - Slight Miss At Idle - Case Study

there are viewers and welcome back to the self minato channel so guys an old five Honda Accord here it's the three liter big v6 and it's kind of stick in it so let's think it's got to be pretty fun to drive but right now it is sick and that's why it's here so the car has a continuing problem of a flashing check engine light when it's at an idle you drive the car down or over it drives fine customers pretty you know aware of this and I guess it's been happening for some time now he's taken the initiative to do you know some diagnostic work himself and he knows he has a cylinder or cylinders with low compression apparently if I remember correctly you know he's gone through and you know check the basics you know long you know including a compression check what else a valve adjustment parently had been done so we know that's good so kind of narrowed down our our diagnostic process a little bit but you know again we're gonna look at it like it's a brand new car you know it's broke you know we're gonna fix it a brand new car to us anyhow I can tell you when I started it on the parking lot to bring it in it does sound like a cylinder a little compression figured when you crank it over it's got a pretty distinct sound so we'll grab a scan tool we'll see which cylinder cylinders are having a problem I'll let you guys listen to what we crank I'm pretty sure you guys have bill to hear beeping get down here and we'll see if we can't put it I'll shoot you know what these don't have clear flood mode I wanna start it holy hard to tell in the video here that one silver as it goes by then you know kind of free wheels a little bit there but yeah the time it does not have their flood mode like a lot of them so we'll do a different thing so one thing we can do while we're right here hopefully really Claire for you we can use our launch and we're going to go into one of the special features where we can actually turn all the injectors off so we're gonna go ahead and do that it's a little bit of a process so once you do this on a Honda to get this to get the injectors to turn back on its no matter just why does it matter pushing button but you actually got to go through and do a PCM reset not just a code clear so we'll let this get done here and this should allow us to crank it over you know without going out and unplugging the coils that way we can have a good listen to it all right so I'll inject you're going to stop reset ECM after this function otherwise the engine will not start so basically all the same thing so we're gonna take now you guys should be able to hear this they hear that where it's not just a very steady you know repetitious crank another thing we can do to prove this is we could do a relative compression test just to gather some data get on a known bad engine so why don't we just go ahead and do that just for the sake of doing it so I'll go ahead and get our Pico scope set up here and now the majority of you guys watch our channel you know you've seen us do this test before but for those of you through patents we're just going to use the lab scope and just a current clamp so it's a really non-evasive test and you know the thought behind it is we're gonna clamp around the battery cable that goes to the starter we're gonna be actually measuring starter current so if you think about it over time the piston travels up it's compressing air you know it makes that you know the easiest way thing but you know that makes a starter you know grown a little bit makes a little higher amperage draw so you're gonna see these Peaks as you know the piston comes up and the serger draws more current and then you know natura essence eyes downward stroke and another one's up there's going to be you know these peaks and valleys for every time it comes up on a compression stroke and theoretically if the cylinder has low compression it's gonna have you know lower amperage draw on the starter because the starter is gonna turn easier so that's what we're gonna be doing and then we should be able to see it and then the easiest way to tell you know well which cylinder is it cuz we'll put a trigger on one of the coils assuming that the Cardiac oils are firing right now you don't have to turn the injectors off I don't know if it shuts off the coil drivers or not I don't believe it does but we're gonna test that out so we'll get a trigger and then at that point all you need to know is the firing order and then you can lay it right over there and I'll show you how to do that so I'm getting hooked up here I did just get a new you test kit from AES wave so I had the old kit here and the guy works at AE s way of swung a deal with me told me that they had a new kit and that he'd allow me to trade in my old kit for one of the new ones so I know every time I use this a lot of you guys that are scope users have asked about it so it's a pretty sweet kit that comes with a ton of you know ropes male and female you know wire piercer is one of the cool things they did a little different is there and plant loops they also put a lead on it so you can do you know voltage and amperage at the same time I just saw one connection so that's pretty cool oh that's the biggest change I see in this kit other than that I think they added a new it looks like there's one extra new set of pins there so that's something new so anybody interested in this like exactly it gives us from AES wave up for a link in the description you know if you're interested I look at those but super handy kit any time I'm using any test equipment I always end up you know grabbing something out of here so whether that's a pro board this an alligator clips got air bag simulators so it's pretty handy just want to throw that out there alright so for our trigger I believe he told me it was a number five that he that he had the worst trouble with so we're just gonna unplug that coil we'll find a trigger wire on it so all these coils will have matching wires except for one and that's gonna be our trigger so it must be this one here that's black with a purple trace I'm gonna probe can go in there it looks like this one here alright so that's gonna be our coil trigger so look that to our scope other part of the scope sucked to ground we'll get our amp clamp hooked up looks like we've got a single wire going right to the battery so we'll put it in a 200 amp motor which would be fine for the cranking current and then it's got a little direction arrow on it shows battery positive in that current flow going that way which I think I believe they call it conventional current flow real current flow a flow of electrons actually goes from negative to positive not positive to negative all right we'll get our scope set up and give it a crank it's on channel 1 we have our current clamp so we'll set that up it's actually picot clamp so we'll go right on here so we got the mm current AB 200 amp mod now we're gonna crank this up to 200 amps we'll leave that like that will turn channel B on let's see it's already had a voltage scale so we're going 20 volts I was kind of yeah we'll just put it down here for right now we'll change our time basis here one second per division and then we'll just throw up a trigger put it on repeat bring that over here so as soon as we start cranking just kind of even that out all right as soon as we start cranking that it's gonna start recording so see it's playing everything should be good I'm gonna hop in there crank all right I should be enough data for us that should stop right on the next screen there we go we're gonna live screaming this pause that will hop back in there you guys come right here that a whole lot better out here but we certainly can't see this in our graph let's bed of crap ground on that yeah let's stick in the zoom in here alright well we can see our trigger event is good enough they can move this down and it does appear that number five so we can overlay that so long as you guys can get it so I don't know the firing order off hand without looking but let's say you know let's see it's five four three two one so it says cylinder one cylinder two so under 304 and then cylinder five has very little current draw and then you know I have to let it go this is cylinder six now you'll see that one has a much higher hump because this one didn't draw much current so the crankshaft actually accelerates a little bit there and it's gonna cause a little more current draw as it comes into that next event so this isn't uncommon to see you know really you know pretty pretty even number Five's low and then the cylinder after the low cylinder is always has a higher peak so but we can see that we number five indeed is the lower contributing cylinder I guess you have to take carefully the terminology you want to say it's the low compression cylinder because theoretically they could all be low on compression just relative to each other number five is lower than the rest I'm gonna grab the firing order just for the heck of it so I just went ahead I grabbed the firing order so it's one four two five three six and I just overlaid them over top of each compression stroke so you can see that falls directly you know at number five which was our trigger so that's all you have to know as a trigger is number five and then you just figure out the firing order from there when I guess observation I will make it's interesting that six four and five you know appear to be the lowest course we expected number three to be a little more elevated there six four and five are on one bank it's on that front bank of the engine the car does run pretty well so that's you know it's kind of something to keep in the back of our mind alright so now we're back in the car we're gonna pop back out we're gonna have to go into ECM PCM reset it's gonna get prompt us there so now that it's been reset some of yo the FCC MPG imagery said I don't maybe low erratic you know so it's gonna have to relearn some adaptive what it should start now some Indians cold what we can do we can just pop in to get some data I manually select them we can look cylinder misfires here see what your primary offenders are offender definitely a cylinder number five counting up on that's pretty good there the Doug show some misfire accounts on some other cylinders say when you bring this thing just off night all runs good to me it sounds like a single cylinder misfire you know why the other counters go up I honestly do not know it does read eat all your misfire counters come off from crank crank shaft variation so surprised the engine light set on right now but certainly is cylinder number five sorry just checking out some scan is looking at fuel trims and stuff here well it's in an idle on bank one is running just about zero percent correction about a one percent correction Bank to where we're having a problem though we can see you know that cylinder is running rich it's taken away what about 13 you know 14 percent you know negative fuel trim so that's to be expected bring it off in idle this is a map Sentra engine map sensor engine and infinitely just went out to what's flashing their fuel trims get a little better but still about a 10% correction for rich condition you know practice that solder you know just can't support combustion obviously as good as the rest so now let's just pop out and just see what temporary code is stored I imagine a 305 you know two four and five and six so and a Pio 300 so pretty interesting how its counting up misfires on those other good cylinders so what I say that we do next you know when I spoke to the customer about this we're getting the job to fix whatever it is regardless I have my suspicions of a bad valves or leaking valve so what I would want to do is I like to gather as much data as I can you know particularly we end up pulling the heads off this you know let's overall health checkup engine so what I would do if it's in my shop and it is I would do you know a compression check on the engine y'all let's see what's what we know number Five's not you know contributing as much as the rest but you know what's going on with four and six is this whole front bank low you know are we think can you know cam timing problem I got that simply because it runs so very good and I don't know I don't know for a fact that these have a cam center on both cams you know as far as you know running the camp print correlation I can't recall right offhand for some reason I think they'll have one cam sensor but I could be wrong so anyhow well we'll take it from there so that's what I would do plugs are easy enough to get on on these we'll pull out all six coils pull the plugs out get our cranking compression we use a scan tool again will shut off the injectors that way there we don't think you know if it's able to fuel pump or something to you push a button then I just you know look for a fuse or relay but that would be another option to disable the fuel system you know pull the fuel pump views let it die you know that way there you can crank it at full throttle and get good crank and compression but we need to get a baseline as you know one car has so I'll go ahead and remove the coils now we're gonna use Pico again just cuz I want to gather the cranking waveforms cranking compression take these out or pop the spark plugs out now if you guys have you know a scope or a graphing multimeter but you don't have a current clamp well you can still do their all to compression test just using voltage over on the motor age YouTube channel Pete Myers he actually did a video on that and how to do that and he got some pretty neat little tricks over there so it's right now I'll grab the spark plug socket I'm gonna be pulled out I'll pull out all six of them and I'm going to zip down through the compression will record all our data and write it down and kind of take our diagnosis from there let's start right here in the front cylinder for like I'd say we're going to be using because we already got the peak while the fact that dude I grabbed there on one eye a big dummy round two there we go right right length wrong size so grab this lesser WPS 500 its Pecos actual pressure transducer and I can put links in the description for anybody who's interested in that who perhaps own zippy Coors considering only one so here we go we're gonna change our probe permit down here we'll pick out WPS 500 range one that's a wrap no that's gonna take us I don't think we're gonna be going over Turner psi oh we'll pick the 500 psi scale just for grins and giggles here we will turn off our second channel because we don't need that anymore all right all right so back in the car I went ahead and I stopped all injector flow again now you don't have to do that but this will stop our results from being skewed so I'm gonna go ahead and just collect one show you guys how that process is so we're gonna go wide open throttle we're gonna crank it we're gonna I got a trigger set on the screen and we'll go you know six or seven bumps here [Music] all right so it's about 7:00 snow but look at the data go back frame 1 we can see our compression event so you know you can see the piston travel up and then I just saw way back down we're just gonna collect our peak compressions right here so we can see that silver is 187 pounds there's a lot more data that can actually be gathered from these but this is what we're after right now and then we're gonna save these waveforms and Kate's are gonna be of any use to us a little bit later on I'm just gonna go through see these label the cylinders and just do that for each one it's pretty much the same as using a regular compression gauge you know you still got the same pretty much the same amount of work either got to record it you know you got to log it all in so it's my habit when I'm doing this working on a car what I'll do is I usually just start a folder for the customer like yeah I just got this label oh six quart misfired idle and then I'll put in all my waveforms I gather that way if I have any questions throughout my process that kamek gosh was number three or what was number one I can't remember it's all right here for future use all right so that's all done I can zip through these so here I've got my DS this is cylinder one and we can see that 232 psi or 223 cylinder two is 206 cylinder 3 is 218 this is cylinder 4 at 187 [Applause] cylinder 5 is at 122 and then cylinder 6 is at 180 ticking I'm going to save all these waveforms here so I don't lose them alright guys real quick uh I gotta go I gotta do I'm sorry I keep getting interrupted do some service work so before I put the pressure transducer way I did take some running compression waveforms I was really hoping that I was gonna be able to see something a little more than what I'm seeing so this is a cylinder number 5 which has a running compression of 82 psi which I was kind of surprised at I did take this right after startup and then the engine leveled out right before I did a throttle snap I just wanted to have the stator for my own mount knowing I've taken a couple classes on insulin or pressure transducer testing so that is cylinder number five that is our low compression cylinder this is cylinder number one and the running compression is exactly the same which I would expect this one to be a little bit higher and of course let's see this is silver 5 this is cylinder 1 I recorded this at this isn't showing up here there we go I did I this captured same thing started the vehicle let it idle smooth very before a snap throttle so this is the same type of capture the only thing that I notice I don't see any valve timing issues as far as you know opening early closing late this is a little bit debatable here usually the bottom dead center mark will intersect this line where the exhaust valve opens but that's you know kind of a general rule and I think that's you know based off cam profile and stuff like that but I did see that this one the maximum vacuum that it went into it did stay even in both vacuum pockets got down to about 9 psi 9.1 sometimes it by 2 so like 18 you know eighteen point two inches of vacuum and then we go to number five here and this got down to about eight point six what's sixteen seventeen inches so the the amount a vacuum that this cylinder pulled into is slightly less but it's even on both sides and if I remember right from classes and maybe wrong in this I really got to look into this again that it's usually an indicator of a leaking exhaust valve John Thornton doesn't fantastic class on this on a VI if any of you guys have subscription to a VI but as far as anything else you know I don't see any any differences between the two to the point I went and did an overlay so this is an overlay cylinder one over top of cylinder number five measured at the same point after startup here you can see this over on my zoom view after started before throttle snaps and these graphs overlay absolutely perfectly so for me because I'm not an expert on insulin or pressure transducer testing it doesn't mean a whole lot to me and the only difference I saw was the amount of vacuum they pulled and that was it so like I say if I remember correctly that typically will you know a leaking exhaust valve can't do that so I say at this point would be the best thing to do you know I've gathered my data I know the state of health of the engine let's focus on its cylinder number five and just do an old fashioned leak down test on it and see if we can figure out where this air is going warzone [Applause] let's see if we can't just real opinion here by the power steering pulley usually to go slowing up you can all right system going down we're okay the engine backwards just a little bit we might be right at the peak yeah so right there it stopped that Center how fortunate is that let me get the leak down tester we'll put it in there we'll see if we can tell where the air is escaping or the being thicker exhaust but like I say my limited knowledge on pressure waveforms is I believe it's gonna be going out the exhaust not only from what I've learned which I'm gonna see if Thornton has any videos on YouTube that I can link where I think he said that or I'm gonna look back on avi and see if I can find the video there which is a paid service so unless you have a subscription API you can't watch it and unfortunately you know it's copyrighted material so I can't even kind of like post that clip of it legally somebody do that and then kind of explain where we're at I think we're going to do but first we need to see where's the air going so we have the leak down tester going down I'm probably gonna have to hold on this wrench here by myself so I got a little help okay so it's gonna want to try to kick over so I'll try to get out where you guys can see it hopefully here and there so we're gonna do is I and the cylinder it's going to measure the pressure differential across an orifice so far it's not pushing on me I get this up 200 psi [Applause] very little so right there we've got about what 70 you guys can see that about 75% blow by and that's alright so it is pushing it does want to push my wrench Center so now what we have to do now that we know we have you know 70% blow by or you know pressure differential we have to see where it's going it's either you know it can be coming out you know oil cap at this leakin past Pistons don't know really here a lot of times a better way to do that is healthy oil dipstick let me get you guys kind of focused in there just a little bit better it does want to push my wrench it's trying to push that piston back down so if sometimes you pull out the oil dipstick you know you'll hear a hissing there of course you know there's other a crankcase you know fresh air that can be going back into the air cleaner but usually if it's in the crankcase you'll hear it you know particularly that I'm on the blow by which I don't hear whatsoever coming out of there so the other option is intake manifold or cylinder and Sylla rattles expect to have a head gasket here we would have seen that like I said I suspect it's going to go out the exhaust so I think for best visual representation because I can't hold this and go listen to the exhaust what we would do is what we've done in the past let's look at small sheet we don't this in the top dead center will put smoke in there instead of air and then visually look to see where the leak is I mean it seemed like them in a birdie book and a little bit of hurry not a stupid physical therapy crap I got to go to I need therapy physical swords I guess I do my special exercises they give me yeah got some arthritis in my shoulders and it's messing up on my muscle in there I guess so I go physical therapy they electrocute me for a while smoke machines looked up we've got a nod at the full beam setting make sure we got smoke got plenty of smoke so we'll put that in there big gossip hot so a lot of times if you're doing this and your converters are hot it'll gobble up all that smoke out of your smoke machines so I'll give it some time that I kind of fill the system we'll look in the intake look it's getting in the crankcase naturally it's coming out there and that will look at exhaust if we see it coming out the tailpipe I mean well I mean well let's want to look at one thing because I'd like to try to dispel any questions where's our overlay so under one and five over this so we got one two three four five and six cranking one and five running relative compression so this is our overlay so there's there's gonna be that question as you know if this is leaking out the exhaust intake what-have-you how do I know it's not an over adjusted valve you know obviously we have a leak airs going somewhere and here's what I would say again I am NOT a expert on insulin or pressure transducer testing I know very little however what I do know is this is an overlay so we're looking at good cylinder versus bad cylinder I can bring our overlay forward so there's our pink or magenta and then in our blue cylinder five is the blue so as I look at this if we had a over-tightened exhaust valve or yeah we'll just focus on the exhaust valve at this point so I'm certain that's where it's going to go on so if we had an over tighten exhaust valve so our piston comes up it's in a compression stroke comes down into you know the decompression where it pulls it down below zero psi and at this point the exhaust valve opens if our exhaust valve was too tight it would open early and close late and just in comparison between you know the good cylinder and the bad cylinder we'll call it we would see that our blue line would be over here to the left and over to the right at the exhaust valve opening event and the exhaust valve closing event that would be noticeable I actually have some saved waveforms where that's happened on a Subaru I had zero valve lash and it was you know clearly noticeable on the waveform that the exhaust valve opening event was early you could clearly see it you know it was far to the left the bottom dead center so this is top dead center higher eighty degrees bottom dead center of the piston and then the Pistons traveling back up the top dead center this is back to bottom dead center and the top dead center getting so that's all four strokes right there I do not believe that we have any valve timing issues on this engine based on what I know what I see here and I don't believe we have in a valve adjustment problem based on what I see hang on guys there's lots of good stuff out there there's lots of good classes put out on insulin or pressure transducer testing and it's it's really difficult to retain it because it's not something we see every day it's not something you do every day you know you try to practice on cars that are good and collect on goods and see what good is but when you get one that's broke you know I mean obviously we could have brought this car in misfires at number five done a compression check on it did you know leaked on tests and you know life goes on here and now about your tools that are but free which you know which is fine that would work done it for years but there's going to be that situation where you know the valve cover is inaccessible a pole to physically see stuff where an insulin or pressure test gonna tell us you know is our cam timing good you know perhaps what valves leaking you know do we have you know running compression problems we have a breathing problem smoke machine back on so that's why I try to use this and implement this on a car that I know is broke because I want to know and this is just frustrating the living crap out of me currently so you know busy and trying to analyze this I'm gonna take this home study to see if I can't get a little more probably gonna watch some other videos on it to see you know if I can make sense of it and also what I'm gonna try and do it I can't guarantee this I take all the data that I've collected in that file for this car and I'm gonna put it on like my Google Drive so I can put a link to that in the video description so if you guys want to look at it and you know see what you see feel free now you're gonna say I don't have a Pico but that doesn't matter you go on Pecos website you can download their software absolutely free and then you can look at these files manipulate and play with them just like you have a Pico that's the cool thing about the company they let you try their stuff before you buy it essentially it's not a trial version it's a real deal so I'll put a link to where you can get the software I'll put a link to where hopefully I've been able to host all nine miles that whole file on this car so you can look at it and you know give me your assessment you know what you think we should have plenty of smoke in the system now and then you know of course hop links too you know if you want to buy a Pico you know I'll have the links area of course that you test get a it's waived they sell both of them so a good place to purchase them right now let's go see if we can find this smoke and I don't think we have to look very hard because there it is come in right out the tailpipe ya don't see any very very little coming out around the dipstick tube which you know no engine seal 100% perfect so you know the the main thing is it's not blooming huge clouds of small course will take and pop off that air tube there and have a look toolbox to time there it is you saw everybody wants to see that let's see all right clamps already loose I do not see any smoke coming out the intake I think it's pretty definitive what we have going on here so I'm going to leave it at that for right now it clearly is leaking out the exhaust I gave my reason as to why I don't believe there's any need to look at valve adjustment because I believe that I can see it I know that I can see it cuz I've seen it before so I'll leave it at that you know I don't see any sense in pulling the velcro at this point at this point we know that sooner has low compression it's causing or misfire and it's leaking out the exhaust valve so I believe it's time to pull the head gathered all the data that we could you know you know to even based off this judging by our and solar pressure transducer test I don't even have to check cam timing we certainly could these are easy enough to do they have inspection holes on both of the covers you know it's rolling up look of course that would just mean that our pulleys are in line of course you could always have it you know a sheared keyways stuff like that but I don't feel that's what we're dealing with in this case in my opinion so I'm gonna make the call at this point the heads got to come off those to you that are remotely curious about checking your timing belt timing without pulling the covers on your hon do you can look down that crankshaft hopefully I can zoom in on this for you guys you're gonna see that little white mark on the balancer that lines up with the bottom of that triangle there in a time of cover now being offset here looks like it might be a little bit off but I'm sure it's right on and then what you'll do it's gotta be number one top that Center compression stroke and then you're gonna pull your inspection holes here on your time and covers you're gonna look in there and there's gonna be a pointer and an indicator on the cam gear I believe it's number one top dead center but you'll see those two marks they'll line up if it's a fault you thought you'll know it that slight little variation there is you know there's nothing that's right on and then there's also one here in the back which may be more difficult to see focus on really cuz we're gonna have to look down to these brake lines so we'll see if we can find that little booger it's gonna be right through there of course it's gonna want to focus on the brake lines but crap that lights a little bit too bright let me just dim that down maybe we can see it better so you have to look you'll look right through this hole in the time and cover my fingers you'll see that the plastic little v-notch it sticks up and then you're gonna see the corresponding notch there on the cam gear on the inside so we can see you know that our cam timing is right on and you know if you want to check your own on your hand do that's how you do it so pretty pretty easy so we're gonna put these rubber plugs back in and I feel confident enough to make a call tear this little guy apart okay so I'm going to leave it at that I gave my reasons as to why I made the assessment that I did sorry if I felt rushed through this video but it's just kind of how it worked out today but I did want to be able to share this with you kind of you know whether what the process is or the process I normally would take on a vehicle that comes in that clearly has low similar contribution and some of the reasons why I do it and and my thoughts behind the data that I gather and we're gonna leave with that I gotta take old Chiba your home I gotta go to my PT and get some electrocution and whatnot that they do Tia and like I said I'm gonna try to you know look in the description box hopefully I can find you know some info for you guys place to put these files links all that business customer says he wants to fix it so that's good so I'm gonna say I've got to order all my stuff I'm gonna order you know the head cylinder head set I'm about water pump all that business and then I'm probably going to get a couple valves just to have here on standby so once we go the machine shop if we need them that we have them and I'm sure you guys probably gonna want me to record this process so hopefully we can make that happen it's gonna be quite similar to the 3.5 we did of course this one's a 3 liter but very very similar so anyhow that's it I got a roll look at the description way down there click that subscribe button if you haven't done that click the bells you get the notifications and find us wherever you can find us and just from our viewers if I can do it you can do it thanks for watching [Music]

Channel: South Main Auto Repair LLC

Views: 356,325

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Id: Y4wF_Nn2EqU

Length: 38min 55sec (2335 seconds)

Published: Fri Sep 22 2017