okay i'm gonna show you a common problem customer here drove through some deep
water on the passenger side check engine lights on and it's not
running right now as you might imagine water and electricity especially
computer systems do not mix that well realize your
computer all those sensors in a car work on a 5 volt reference signal not
much power very low amperage maybe a few thousands
of an amp power any electrical system part gets water on it
you can get problems from corrosion or just plain
the water is there and it inhibits the flow of electricity
so as you can see under the hood it's all kinds of electronics
he went over on this side which water can splash anywhere but
we got to figure out what's wrong now thankfully the check engine light is on
so we'll turn the key on and we'll see what
it is and this guy's a kind of sneaky there's
a little access panel here we take it off there's the obd port so we can plug
it in of course i have it upside down you'd
know that now we'll see what's going on now since the customer tells me the
light wasn't on until after he went through the water
we know that's gonna have something to do with the problem and as we see it's
got two codes and we have cylinder number two misfire
and it's twice so the problem is cylinder number two
is a modern technology in my grandfather's day
that you had to pinpoint everything by yourself take a lot of guesswork
this tells a cylinder number two misfire checking the freeze frame data now
it's gonna tell us exactly what happened and here's when it happened gives us all
the information and here's all the information
now we can see it happened when he was going 47 miles an hour
and the short-term fuel trim it was adding 9
fuel but the long-term fuel trim is zero now that might not seem much
to you but it gave me a real good idea when a trip to code was going 47 miles
an hour and it had to add about nine percent
fuel meaning it wasn't getting enough fuel
that was adding fuel well guess what these kias are notorious
for having problems with the fuel injection wiring anyway
so we'll pull this stupid cover off there it goes and realize that this is
cylinder number two you go from the front
one two three four this injector i'm assuming got wet
like i said earlier computer systems work on very low voltage
very low amperage few thousands of an amp you get any kind of water fuel
injection wiring to make them not work right
so what i'm gonna do is spray them with some electrical spray cleaner
now you can buy electrical spray cleaner that says electrical spray cleaner
well i happen to have a case of this mass air flow sensor but the mass
airflow sensor is electronic it's pretty much the same stuff it
doesn't leave any residue so i'm using this map spray sensor
because i'm too lazy to go to the store and buy a can that says spray electrical
cleaner this is the same stuff and what we're
gonna do is we're gonna squeeze the number two
and pull it off and we're gonna clean everything
the injector where it plugs in the connectors do a really good job
you might as well do the number two ignition coil too
maybe it got wet and on the old day we used to use wd-40
when stuff got wet because things were simpler then they
didn't have ignition coils on each spark plug
they had a distributor and spark plug wires if the wires got wet
you could pull the wires off then you could spray them with wd-40
because that displaces water but understand you got thousands of volts of
electricity on an old-fashioned spark plug wire on
the ignition coil you only have that little bit of power
coming at the top the thousands of volts are deep down
inside and in this case you could be an
absolute fanatic if you wanted to take this off
but this has a big rubber seal on it an odds are no water got inside there but
let's say go through some water and you're in the middle of nowhere
heck get some wd-40 it doesn't hurt electronics and it does displace water
so if you got water and it's shorting stuff off you can spray the wd-40 all
around then just get a rag and wipe the excess
off and often that will stop your problem
that's what they used to do back in the day
if somebody went through water the first thing we do we just get some wd-40
we spread the distributor cap and all the wires then it absorbed the water
then we'd wipe it down with the rag then we'd start the car and drive it but
modern cars are a little more complex than that
so you're better off with spray electrical cleaner or this maf spray
sensor cleaner which is the same stuff you don't want to use stuff like
carburetor cleaner because that can conduct electricity and short stuff up
you want to use stuff that's made for electronics well now we'll start up
and see what it sounds like as we go inside we'll stir up
starts right up i did push the button on my computer to reset
the check engine light it's been reset so it's not on now
so we'll take it for a good half hour ride and see how it does
you want to do a good road test will you drive in town five
ten minutes on the highway 10-15 minutes that'll give it a good road test to see
if anything's going to come up then we'll just look at the data
after the road test and you especially want to accelerate harshly like this
because you want to stress the motor to make sure the ignition and the fuel
system is working at top efficiency
if you road test things like a little baby you might not stress the engine
enough the more you stress the engine the more
any minor problem is going to show up on both the scan tool and the check
engine light now we're back home let's plug the scan tool in again
well the check engine light stayed off look at the live data and if we check it
out here we'll see the short term fuel trim
is now minus 1.6 or minus 0.8 there minus 0.8 zero and when 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
seems that that fixed the problem so the next time you drive through water and
your car starts running poorly now you know how to figure out what it
is and fix it yourself just pray you don't suck
water into the engine past the air filter because that can hydro lock your
engine then the piston rods and goodbye engine
so be careful around water and here's some bonus questions and
answers mr mech martinez says scotty would you
take on a buick lesabre with a v6 3800 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
god it sells me auto parts he bought one for one of my customers for a thousand
bucks he's still driving a stupid thing around
so 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 one
they have no resale value paul valene 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 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 by fours 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 you don't always want to go with the most expensive thing it's like the
guys that 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 the other things out first 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 and unless you like
falling into endless money pits i would get rid of it as soon as
possible jason says scotty can i change the alternator pulley for more
alternator power you can make it smaller or bigger if you can find one but of
course then your fan belts might not fit right in most cases the alternators on
vehicles work perfectly fine the way that they were designed
and unless you're sitting there idling all day long your engines spinning fast
enough to charge you with any normal design these days
so if you never want to miss another one of my new car repair videos
remember to ring that bell