4 Signs Your Engine Has a Serious Problem

here i've got an easy repair anyone can do themselves in this case it's a 2017 kia forte the check engine light's coming on it isn't running right we'll open the hood but thank goodness the check engine light is on so rather than guess we'll use a computer i hooked it up to cars you can see it says pl 301 cylinder one misfire detected now unfortunately these po codes are what are called generic codes lots of things can make an engine misfire could be the spark plug could be the ignition coil could be the wiring could be the computer and just don't think it's ignition system you got a bad fuel injector that can make a car misfire gasket intake gasket head gasket on number one that can make it misfire but the absolute simplest thing to do is this first we'll take the stupid beauty cover off get it out of the way and here's the ignition coils one two three four now it says number one is misfiring so we're gonna take that out you just unscrew it sometimes they're hard to get out so you wiggle them and unplug them in this case it's a dual system you have to make it harder than normal so you gotta click it up then squeeze it to get it off it won't come off if you don't push that up the number two ignition coil get that out wiggle it pull it off get the screwdriver unlock the tab there we go then we flip it over and squeeze it off it comes then we'll do a simple test we'll put number two in the number one hole and number one in the number two hole put the bolts back in got to make sure they're lined up they got to line up with their hole and get them snug and remember to plug them in this one plugs in here snap this one plugs in there we'll leave the top off it's just a stupid beauty cover then we'll just push reset on the scan tool and that resets it so there's no coats then we'll take it for a little drive well i dried around the light came back on so that's good now we can check it so we'll plug the working end in again here we go see what it says here we go it's going to read it well it's got one code and the code is po301 misfire cylinder number one so it's not the coil because it's still not firing right well guess what now we're back to square one but at least we didn't waste any money we swapped the cause but the misfire stayed where it was originally so it's not the ignition coil so put the coils back take the other one off so we're gonna check the spark plug and lo and behold the spark plug is loose it's not in tight enough we're gonna check it out anyway it doesn't look bad but who knows since this one's loose we're gonna check them all and i'll probably replace them anyway take them all out see if any of them are loose too stick them in spark bug holes these are a little loose too they put it all back together and see what happens make sure i put them in the right hole this is the green one that's number one and now we're missing one there it is there's number two and we'll hook all the cables up one two those we didn't unhook and then we'll bolt them all back in all four of them we'll start her up again see what happens let's run a good now so we'll take it for a road test and see what happens and now i'm back it's running fine no check engine light i did put in four new spark plugs the old ones had gotten loose but got 80 000 miles so i put in new spark plugs no more misfiring and you might wonder why did it only have a misfire on one cylinder and not all of them if the spark plugs were worn out well even though it's a machine things don't necessarily wear evenly in this case the number one spark plug got looser and wore more than the other spark plugs did but you're gonna change them change them all don't go through the trouble of guessing here and there change all four of them make sure they're nice and snug so they don't get loose again and it won't have misfires in this case just to misfire on one cylinder not on the others eventually you probably would have done them all but we want to fix cars so when you fix them fix them right if one's bad change them all this toyota rav4 just came over here the check engine light's on it's got the code po171 which means the engine is running too lean now unfortunately there's a whole bunch of things can do that so you have to start logically go under the hood and look at the most logical things first now running too lean means that the combustion inside the engine is burning at a two-lean ratio meaning either it's not getting enough fuel so it runs lean or it's getting too much air and it's running too lean now one of the common things for that is a vacuum leak if a hose has come off if a gasket's broken and sucking air into the engine it'll run too lean so that's the first thing you look for and if you're really smart and have just a regular scan tool you can get a 40 one that does this it's got the code that means there's data stored so you go to the section on your computer it's called freeze frame data here it is here view freeze frame data so you look at it you get tons of information there and the main thing when you're running too lean is you want to look at when did it occur it'll show you the speed of the car if the speed of the car is zero and that code tripped when it was idling that generally means it has a vacuum leak because when the car is idling the engine isn't moving that fast so it has a little less vacuum pressure if you get a vacuum leak and you're idling with a low vacuum pressure that'll set it down quite a bit percentage-wise can make it run lean then it trips the code realize that the codes are tripped when the computer sees like 20 or more off value so it's got to be a reasonable amount this lean code tripped when you're going 65 miles an hour odds are it's not a vacuum leak because it's 60. the engine's spinning like that's got tons of vacuum pressure it's got a little vacuum leak it's not going to bother it that much because the leak is going to be a smaller percentage of what it is when the engine is only idling a much lower vacuum pressure so if it did occur at lower speeds or at an idle you want to look all around for vacuum leaks and on these toyotas it's often a vacuum line it comes off a lot of times the one back here behind the air filter gets pulled off when somebody changes the air filter but that one's not bad sometimes they come off of the pcv system but that's on nice and solid if you can't see or hear any vacuum leaks when the engine's idling use your ears and if you hear a sucking air look around you can do like i showed in a previous video get a little wd-40 with the spring nozzle spray it around and if you get say on the intake manifold and it starts to change the idle you know it needs an intake manifold gasket but the code tripped on this one when it was going 56 miles an hour so it happened at a higher speed now if you get a running too lean at a higher speed and you look at the trouble code freeze frame data and happen at higher speed in this case 56 miles an hour odds are it's not a vacuum leak but it's something in the fuel injection system you could have a clogged filter you could have a weak pump you could add a bad mass sensor those are the most common things to check for so the first thing you do would be check the fuel pressure now here's a warning if your fuel filter is easily accessible change the fuel filter first because fuel filters if they clog up guess what after the filter the pressure will go down make it run lean because you don't have enough pressure to spray the fuel injectors correctly so if you do have a fuel filter that's easy to access go ahead and change it now on my old celica hey there's just two bolts you take off you replace the filter so that's what i would do but on this modern ram 4 fuel filter is inside the gas tank now you don't have to drop the tank but you got to take the back seat out then you have to take the excess panel then you got to pull the fuel pump assembly out because the filter's built in there now toyota gently wants to sell you the whole fuel pump assembly for six seven hundred dollars with the filter built in you can buy a filter but in this case hey you're not gonna just change the filter on the lark because it's such a pain in the butt so we're gonna just check the fuel pressure it's supposed to be between 44 and 50 pounds per square inch we test it and that's what it is well then we don't have to worry about changing the fuel filter because the pressure's coming out fine anyway since it's such a job to get in there and change the filter we're just going to check the pressure on this so we'll get up my fancy fuel injection tester kit and i do mean fancy because toyota over the ages they've been kind of a swine about checking fuel pressure they never had test valves on them most of them don't anyways modern anyways they all went that way it's cheaper to make but you got to get a special adapter you hook it on the fuel line and then check it with a gauge you're going to have to buy the special toyota adapter which isn't cheap so you might want to pay somebody else to do this and in this case it's fine it's about 50 51 pounds so we know the fuel pressure is good so it's not that it's not getting enough fuel next thing to check is the maf sensor mass airflow sensor now on these toyotas notorious are getting dirty and giving false readings so they can make them run lean it's right here simple thing to get to right here there it is now you can only clean these things with mass airflow sensor cleaner don't try anything else got to leave no residue yeah this stuff costs a lot sometimes these cans are like 10 12 bucks but they last for a long time you don't need a much cleaner cleaner you just remove it from the vehicle just on plugs you got to squeeze the heck out of it then remove the two phillips screws that hold it in place they just screw out and essentially wiggles and comes out now cleaning is pretty easy there's a little metal piece here right in here you want to clean the heck out of that and there's also one inside so for that you spray it in the front then you spray it on the other side of the hole and it cleans the stuff on the inside and here comes the part that everyone hates patience something hardly anybody has these days a very volatile cleaner you want to do it outside so you're not breathing it you want it to completely air dry so there's no residue of vapors on it when you start it up because if you clean it put it right in and start it off a lot of electricity goes through here those vapors can short things out and even worse don't clean them on the vehicle if you take the hoses off and clean it from the inside then you got all that vapor in there don't do that take it off and clean it most cars it's not that big of a deal getting it out and like i say if you clean it wait about half an hour because i've seen people who didn't they were in a hurry or cleaned it inside and then boom the electricity hit the vapor burn things out then they had to buy expensive sensors do it externally let it air dry that way you can't hurt anything then after half an hour or so you just put it back in its hole the same way it came out make sure it's seated in because there's an o-ring in there and you put the two screws in one and two and of course don't forget to snap the electrical connection in there then we'll just close the hood then erase the card just push erase yes yes this now erases the code so the code's going to take it for a good road test now sometimes coats take a long time to come back but take it from the highway in town maybe half hour trip if the light doesn't come back on then you just drive it and after two three weeks it doesn't come back you fixed it in this case since this is a 2.5 liter engine when it's idling the data the mass airflow should be somewhere around two and a half grams per second that it's flowing when it's at idle and drive so i checked that it was like 2.64 which is perfectly fine for this if it had been really low like 1.6 that would mean it's giving it way too little gas and if the reading had been really high like 4.7 then it would give it too much gas but then it would be running rich not lean if it's running below the parameters then it's going to run lean because it thinks there's less air coming on so it gives it less fuel now in this case when they get dirty they often give a false reading we're hoping that's what it is after a half hour drive it didn't come back on you really like i say give it a couple of weeks because these things can be very slow at picking things up but if it never comes back then you know it was just a dirty mass airflow sensor now in the case of this mercury grand marquis the coolant is leaking on the front where the radiator is so we'll take this plastic shield out of the way then we'll get a flashlight and start looking around realize the radiators are made out of aluminum even they're called plastic readers because they have plastic ends and as we look around we can see there it's leaking and right there somebody attempt to fix it using epoxy but the epoxy isn't working it's leaking all over the place from my experience it's a complete waste of time trying to fix a plastic radiator and here's why 21 years old the plastic gets brittle if it cracks and you fix a crack the whole thing's brittle it's gonna crack somewhere else or the brittle plastic might not even hold the epoxy so when it's broken like this just replace it but it's not as bad as you might think my customer bought a brand new radiator for it now this brand new radiator only cost 119 bucks at a discount auto parts store they're amount of plastic and aluminum they're cheap to make you can buy chinese ones no problem long as they fit like i said made in china not matter long as it fits now changing the radiator isn't that bad you got to take all the plastic junk off bolt it to the radiator first so we'll take the overflow tank off there we go but this is in the way so we got to take the mount off too so we'll remove the radiator mount happens to be the same size bolt off comes the mount then we get to a little spring that holds the tank on it's kind of a pain so take the top one off instead it's easier to get to so wiggle it some more and see if we can get it off there now that's all we can reach behind where the overflow tank is you can unbolt the toweling for the fan one on this side and one on that side while we're at it we'll kick the drain pan under here and disconnect the upper radiator hose now i use a special tool for that it's a clamp remover it's a lot easier than using pliers pliers often slip these don't you just clamp them so they're real tight then the clamp will slide off we can leave it on and then pull the hose off and off goes the hose we'll move it out of the way then we can take the other bolt off that holds the radiator fan connelling on then as you can see the whole fan assembly moves out of the way you know it's an old car it's about an electric fan so with an electric fan it's a lot easier not to unbolt all that fan clutch you just take this out of the way then we'll remove the other bolt that holds the other side of the radiator on kind of old and corroded it's going to be kind of hard to get off so push hard and then start now it's going to come off you don't want to stretch take it off get out of the way now the radiator seems to be sticking on the bottom so let's get on to here and check it out a couple of bolts down here we got to take off too and while we're under here we'll take this hose off the bottom hose so we can get it out easy then once it's loose we can pull it off sometimes they stick around pretty hard eventually they'll pull off then we'll remove the coolant lines here pull them off to get enough room to pull out the radiator that's an extra cooler here normally they're built into the radiator but not on this one so it actually makes this a somewhat easier job that it comes bites in every inch then you get the new radiator that goes over there because the other one's on the bottom slide it in gotta do a lot of wiggling here finally it slides in down before i forget we'll put the mounts on we want to make sure the mounts line up on both sides then we'll put the coolant hoses back on and as usual the one clamps disappeared so i have a box ready to put regular clamps on they work better anyways don't stick the fan back on as you can see here it snaps in place then you bolt it on each side now we'll put the tank back in place bolt it on put the hose on to put the top radiator hose back on we'll try the pliers this time getting it on is usually easier than getting it off and it certainly was and go back onto the car you don't want to forget the other hose you'll have a giant mess there's the hose goes right on there and we'll put the clamp on and on it goes nice and tight and then we tighten the bolts on the bottom back up here comes the easy part fill it up with coolant in this case it's the old ford coolant we put in 50 coolant and 50 water let's start the vehicle up to warm it up that cool and half water this is the water handle now unfortunately as it's warming up check it out a bunch of smoke is coming out of the exhaust as you can see it has no tags so i'm guessing that he drove her with a hole in the radiator probably blew the head gasket only time will tell but with this much smoke coming on i'm guessing the head gasket's blown and you just pour it up to the top put the cap back on take off the prop rod then pray the head gasket is not blown only time will tell on that one one of the most annoying things is your car's running okay but you got to get it inspected and it fails to test when we plug in the old scan tool on any scan tool we'll read this even a 20 dollar one it shows it's got po100 mass volume airflow a circuit and here's how that circuit works this is a mass airflow sensor inside it little electronic part it measures how many grams of air flow into the engine per second and then tells the computer how much fuel to send to the fuel injectors so the car runs perfectly so let's open the hood and find it here it is right here bolts on here snaps on here now if we look closely we'll see there's no frayed wiring or anything sometimes the wiring gets frayed sometimes that's the problem sometimes you can even clean them with mass airflow sensor cleaner you want to use just this because it leaves no residue but i've been working on these things for years and i know when it gets that particular coat on a nissan it's a problem in the circuit it's not dirt or anything not running rich or lean there's a problem in the circuit from my experience in these it's always the sensor itself is just wearing out now if you feel lucky you can take it out and cleaning i got a whole video on cleaning it make your car run better with a little spray cleaner you can watch that and once you feel real lucky but with this particular coat there's a problem in the circuit and from my experience there's only three things that can do that a bad sensor bad wiring or a bad main computer now i've looked at this wiring i don't see anything frayed and where it frays it's always at the end where the sensor is i see them where they get brittle where they come apart i'm gonna unsnap it just to make sure it's not corroded and green though so we'll squeeze it and pull it off ah let's look inside as you can see it's pretty well sealed with these seals everything's shiny and metal there's no corrosion there when we look inside here it's kind of dark it doesn't look bad but i gotta take it off and inspect it in the sun so i'll unscrew this that's this is all one piece we'll just i'll bolt the air filter box and pull the whole thing off out it comes now as you can see in the sunlight this is crystal clean not dirty no problem with that we're just going to replace it easy job just take the bolts off it's a lot easier doing this once you get it off the car all kinds of working room here even that one's kind of tight because that's in the way not typical take all those off and normally you got to measure which way it goes so you don't put it backwards it's got a little marker on here and it says airflow goes this way but in this case you don't have to worry because one end bolts on the other is different so you can't put this one on backwards a lot of them both ends are the same and you could put it in backwards you wouldn't run right but this it only bolts on one way so you don't have to worry with this design and here you want to use a new one rebuilt ones you never know this is brand new it's already got a new gasket just bolts on get all four bolts on and make sure they're all tight get them nice and snug you don't want any air leaking past it then flip it over and do the other side it's important that you have an airtight seal because this is all filtered air you don't want non-filtered air with dirt in that will ruin these things these are hot mass airflow sensors when you shut the car off it burns any impurities off these wires by getting them glowing red hot if you get any dirt on that it'll make it burn itself out just like if you touched the filament of a light bulb with your greasy hands it'd ruin it so make sure it's nice and tight now we put it back on first thing slip it over the rubber then when i slipped over with the air box in its place make all the snaps click realize there's one's up here too and one you can't even see on the other side but you'll hear it click when i hit it there then we just tighten up the clamp get it nice and tight you don't want air leak in there especially and while you're at it go to the other side follow it make sure everything's solid make sure that's all bolted on tight it is okay then we go back inside and what we do is with the scan tool hooked up we will turn the ignition key on so the key is on the idiot lights are on but the car is not running then we go to the cartridge and go back and what we want to do is erase codes so we'll go to diagnostic codes up here erase codes yes so we click yes guess we gotta click it twice there then we enter turn key on with engine off enter now it's erasing the code you have to erase it because if you fix it eventually it will erase itself but they could take a while and this is instantaneous you can see now it says there's no codes but we don't trust anyone so we'll go back we'll go back to read codes and let's see what it says no codes found so now it's reset and now comes the easy boring part we just start it up and let it warm up we've reset it but cars have what's called a drive cycle and in order to pass the emissions test it has to go through the drive cycle so we're going to take it on a highway going 55 miles an hour or faster then drive it in town a little and see what happens what we're gonna do here is we're gonna go to special functions as we do special functions it's quite interesting we want the global ob2 and what we're going to is the drive cycle monitor and as you can see here there are one two three four five incomplete monitors so restart the car and we're gonna watch these now there's only four it's already reset one those vehicles it'll pass inspection that it has to have just one monitor incomplete there's four now but this is an old car it's a 98 and back in those days you're still allowed to have two incomplete so we just have to drive it until there's only two incompletes then we can get it inspected and as i said you gotta drive on the highway a while at 55 60 miles an hour so here we go and once you know i got a road testing going fast here i am in a massive traffic jam in houston isn't that just typical just realize that sometimes it takes a while especially these older cars drive it and watch the monitors until it's down to two well now it's getting down there and hooray now it's down to two we can go back now as i said most modern cars when they're 2000 or newer you can only have one mil not ready to pass the test but this is a 98 so with two mills not ready it will pass the test okay now there's only two mills not ready that means this particular one in 98 will pass the test but we got to make sure one thing we're going to go back diagnostic codes here we go and pray it has unsuddenly while we were driving so here goes nothing read codes no codes found that means it's going to pass the emissions test and we succeeded hurrah sometimes it's pretty easy job if you use your noggin so if you never want to miss another one of my new car repair videos remember to ring that bell [Music] you

Channel: Scotty Kilmer

Views: 529,037

Rating: 4.9444628 out of 5

Keywords: auto, auto repair, car, car diy, car repair, cars, diy, how to, mechanic, repair, scotty kilmer, car review, 5 minute crafts, car advice, car engine, car hacks, car life hacks, car maintenance, car repairs, car tips, diy car repair, diy life hacks, diy projects, doing this, engine, engine maintenance, engine repair, engines, expensive car repairs, expensive repairs, life hack, life hacks, engine problem, engine problems, 4 signs your engine has a problem, repairing engine

Id: UftUt5k4hAU

Length: 25min 5sec (1505 seconds)

Published: Tue Jun 08 2021