**Troubleshooting Car Problems with a Scan Tool**
I recently had to reset the check engine light on my computer and it's been working fine since then. To test its performance, I decided to take it for a good half hour ride and see how it does. We'll drive in town for five minutes on the highway, 10-15 minutes that will give it a good road test to see if anything's going to come up.
**Understanding Engine Performance**
When driving, especially accelerating harshly like this, we want to stress the motor to make sure the ignition and fuel system is working at top efficiency. If you drive with a little baby-like approach, you might not stress the engine enough, and any minor problem will be less likely to show up on both the scan tool and the check engine light.
**Road Testing**
We're back home now, let's plug in the scan tool again. Well, the check engine light stayed off when we checked it out here. Let's look at the live data. If we check it out, we'll see the short-term fuel trim is minus 1.6 or minus 0.8, there's zero and then it tripped that code for misfire on cylinder number two. It was adding fuel, it was like eight-nine percent, it was adding now it's either subtracting a little or it's perfect. This seems to have fixed the problem, so next time you drive through water and your car starts running poorly, you know how to figure out what it is and fix it yourself.
**Preventing Engine Damage**
Just be careful around water because if you suck water into the engine past the air filter, that can hydro-lock your engine. That means the piston rods and goodbye engine. So, be careful around water and here's some bonus questions and answers:
**Q&A Session**
Mr. Mech Martinez says, "Scotty, would you take on a Buick Lesabre with a V6 3.8L motor?" Those are great motors, those motors can run forever. The rest of the vehicle is okay, it's not fantastic, it's a GM vehicle and their quality has been going downhill gradually over the last 30 years. So, they're not the greatest vehicles in the world.
Those are great engines but if you can get a used one cheap enough, it could be a good knock-around car. It sells me auto parts he bought one for one of my customers for a thousand bucks. He's still driving that stupid thing around, and what the heck, you want a car? Knock-around car for driving places if it's cheap and it runs good, now it can still last a while just don't pay much for it. They have no resale value.
Paul Valente says, "Scotty, gotta know what Tahoe 4x4 feels like." The brakes are on is it the transfer case? Okay, the first thing you want to do when you think they're on drive it when you think it's on, pull it in, jack it up in the air. See if the brakes are on maybe they're sticking on who knows.
**Expert Advice**
Now if they aren't then check the rear versus the front and if the front are real tight it could easily be the transfer case going up because normally it's just running on the rear. Now, if you only have it on the rear and not the front four-wheel drive when you're driving it doesn't stick odds are it is the transfer case.
There's a lot of things that go on with those things, you want to jack it up and see first. Don't always want to go with the most expensive thing it's like the guys who say oh man I think I need a computer in my car. Well maybe you do maybe you don't. Don't start with the most expensive thing figure out the other things out first.
**Trade-in Advice**
My Cox says, "Scotty, should I trade my 2013 BMW 328i four-cylinder sedan for a 20-20 Toyota Corolla hatchback manual transmission?" Definitely trade in, yeah I would definitely trade you're not gonna get much for a BMW nobody wants to use BMWs. Well whatever you can get for what the heck. The Toyota might last you forever.
The BMW is seven years old and it's soon to be if not already an endless money pit. Unless you like falling into endless money pits, I would get rid of it as soon as possible.
"WEBVTTKind: captionsLanguage: enokay i'm gonna show you a common problemcustomer here drove through some deepwater on the passenger sidecheck engine lights on and it's notrunning right now as you might imaginewater and electricity especiallycomputer systemsdo not mix that well realize yourcomputer all those sensors in a carwork on a 5 volt reference signal notmuch powervery low amperage maybe a few thousandsof an amp power any electrical systempart gets water on ityou can get problems from corrosion orjust plainthe water is there and it inhibits theflow of electricityso as you can see under the hood it'sall kinds of electronicshe went over on this side which watercan splash anywhere butwe got to figure out what's wrong nowthankfully the check engine light is onsowe'll turn the key on and we'll see whatit isand this guy's a kind of sneaky there'sa little access panel here we take itoff there's the obd port so we can plugit inof course i have it upside down you'dknow that now we'll see what's going onnow since the customer tells me thelight wasn't on until after he wentthrough the waterwe know that's gonna have something todo with the problem and as we see it'sgot two codesand we have cylinder number two misfireand it's twice so the problem iscylinder number twois a modern technology in mygrandfather's daythat you had to pinpoint everything byyourself take a lot of guessworkthis tells a cylinder number two misfirechecking the freeze frame data nowit's gonna tell us exactly what happenedand here's when it happened gives us allthe information and here's all theinformationnow we can see it happened when he wasgoing 47 miles an hourand the short-term fuel trim it wasadding 9fuel but the long-term fuel trim is zeronow that might not seem muchto you but it gave me a real good ideawhen a trip to code was going 47 milesan hourand it had to add about nine percentfuel meaningit wasn't getting enough fuelthat was adding fuel well guess whatthese kias are notoriousfor having problems with the fuelinjection wiring anywayso we'll pull this stupid cover offthere it goes and realize that this iscylinder number two you go from thefrontone two three four this injector i'massuming got wetlike i said earlier computer systemswork on very low voltagevery low amperage few thousands of anamp you get any kind of water fuelinjection wiring to make them not workrightso what i'm gonna do is spray them withsome electrical spray cleanernow you can buy electrical spray cleanerthat says electrical spray cleanerwell i happen to have a case of thismass air flow sensor but the massairflow sensor is electronicit's pretty much the same stuff itdoesn't leave any residue so i'm usingthis map spray sensorbecause i'm too lazy to go to the storeand buy a can that says spray electricalcleanerthis is the same stuff and what we'regonna do is we're gonna squeeze thenumber twoand pull it off and we're gonna cleaneverythingthe injector where it plugs inthe connectors do a really good jobyou might as well do the number twoignition coil toomaybe it got wetand on the old day we used to use wd-40when stuff got wetbecause things were simpler then theydidn't have ignition coils on each sparkplugthey had a distributor and spark plugwires if the wires got wetyou could pull the wires off then youcould spray them with wd-40because that displaces water butunderstand you got thousands of volts ofelectricityon an old-fashioned spark plug wire onthe ignition coilyou only have that little bit of powercoming at the topthe thousands of volts are deep downinsideand in this case you could be anabsolute fanatic if you wanted to takethis offbut this has a big rubber seal on it anodds are no water got inside there butlet's say go through some water andyou're in the middle of nowhereheck get some wd-40 it doesn't hurtelectronics and it does displace waterso if you got water and it's shortingstuff off you can spray the wd-40 allaroundthen just get a rag and wipe the excessoffand often that will stop your problemthat's what they used to do back in thedayif somebody went through water the firstthing we do we just get some wd-40we spread the distributor cap and allthe wires then it absorbed the waterthen we'd wipe it down with the rag thenwe'd start the car and drive it butmodern cars are a little more complexthan thatso you're better off with sprayelectrical cleaner or this maf spraysensor cleaner which is the same stuffyou don't want to use stuff likecarburetor cleaner because that canconduct electricity and short stuff upyou want to use stuff that's madefor electronics well now we'll start upand see what it sounds likeas we go inside we'll stir upstarts right up i did push the button onmy computer to resetthe check engine light it's been resetso it's not on nowso we'll take it for a good half hourride and see how it doesyou want to do a good road test will youdrive in town fiveten minutes on the highway 10-15 minutesthat'll give it a good road test to seeif anything's going to come up thenwe'll just look at the dataafter the road test and you especiallywant to accelerate harshly like thisbecause you want to stress the motor tomake sure the ignition and the fuelsystemis working at top efficiencyif you road test things like a littlebaby you might not stress the engineenoughthe more you stress the engine the moreany minor problem is going to show upon both the scan tool and the checkengine light now we're back home let'splug the scan tool in againwell the check engine light stayed offlook at the live data and if we check itout here we'll see the short term fueltrimis now minus 1.6 or minus 0.8there minus 0.8 zero and when it trippedthat code for misfire on cylinder numbertwoit was adding fuel it was like eightnine percent it was adding now it'seither subtracting a little or it'sperfectseems that that fixed the problem so thenext time you drive through water andyour car starts running poorlynow you know how to figure out what itis andfix it yourself just pray you don't suckwater into the engine past the airfilter because that can hydro lock yourenginethen the piston rods and goodbye engineso be careful around waterand here's some bonus questions andanswersmr mech martinez says scotty would youtake on a buick lesabre with a v6 3800motorthose are great motors those motors canrun forever the rest of the vehicle isokay it's not fantastic it's a gmvehicle and their quality has beengoing downhill gradually over the last30 yearsso they're not the greatest vehicles inthe world those are great engines but ifyou can get a used one cheap enough itcould be a good knock around cargod it sells me auto parts he bought onefor one of my customers for a thousandbucks he's still driving a stupid thingaroundso what the heck you want a car knockaround car for driving places if it'scheap and it runs good now it can stilllast a while just don't pay much for onethey have no resale value paul valenesays scotty gotta know what tahoe4x4 feels like the brakes are on is itthe transfer caseokay the first thing you want to do whenyou think they're on drive it when youthink it's onpull it in jack it up in the air see ifthe brakes are onmaybe they're sticking on who knows nowif they aren't then check the rearversus the frontand if the front are real tight it couldeasily be the transfer case going upbecause normally it's just running onthe rearnow if you only have it on the rear andnot the front four by fours when you'redriving it doesn't stickodds are it is the transfer case there'sa lot of things that go on with thosethings you want to jack it up and seefirst you don't always want to go withthe most expensive thing it's like theguys that say oh man i think i need acomputer in my carwell maybe you do maybe you don't don'tstart with the most expensive thingfigure the other things out firstmy cox says scotty should i trade my2013 bmw 328ifour-cylinder sedan for a 20-20 toyotacorolla hatchback manual transmissiondefinitely trade in yeah i woulddefinitely trade you're not gonna getmuch for a bmw nobody wants to use bmwswell whatever you can get for what theheck the toyota might last you foreverthe bmw isseven years old and it's soon to be ifnot alreadyan endless money pit and unless you likefalling into endless money pitsi would get rid of it as soon aspossible jason says scotty can i changethe alternator pulley for morealternator power you can make it smalleror bigger if you can find one but ofcourse then your fan belts might not fitright in most cases the alternators onvehicles work perfectly fine the waythat they were designedand unless you're sitting there idlingall day long your engines spinning fastenough to charge you with any normaldesign these daysso if you never want to miss another oneof my new car repair videosremember to ring that bell\n"
