Hey, friends.
It's Len here from 1A Auto again.
Today, I've got another top problems video for you, but this time it's going to be on
a Gen 4 Nissan Altima.
We're going to jump right into it and start with the safety issue.
Let's get under the hood.
So, here we go with the first safety issue that I wanted to talk about is the cam position
sensor and the crank position sensor.
If you were to go right underneath the hood, you'd be able to find one of them.
That would be the cam position sensor.
It's located right underneath the plastic cover.
Generally speaking, what happens is that between one of these two sensors, if not both, they
intermittently have issues.
When this happens, it's going to lead to some very scary things.
You could be driving down the road and the vehicle could stall right out on you, or maybe
you try to start the vehicle and it just doesn't want to start.
Both of these things can be scary and, of course, it can also be unsafe, so we want
to make sure we mentioned it to you.
You could try to test these parts and maybe today they test fine.
Maybe tomorrow morning when it's cold out or wet out, they don't test fine at all.
Generally speaking, the best way to cure this would be to replace them both at the same
time.
They're not super hard to do, and they're readily available in most places.
Now, Nissan does have a recall for only very specific VIN numbers on this actual issue.
So, what you'd have to do is contact the dealer and find out if you're covered underneath
that recall.
If you are, great.
If not, just go ahead and replace them.
Oh, man, the oil is low again?
Come on.
You know what?
That leads us into the next problem that I want to talk about on these.
It's located right underneath the backside of the engine here, and it's the oil cooler
O-rings.
Let's get into it.
All right.
So, now let's get underneath the vehicle safely, of course.
Let's assume you're under there and you're looking up at the backside of the engine.
That's exactly where you're going to find the oil leak.
Generally speaking, it's going to start at the oil cooler, and it's not necessarily the
oil cooler itself, it's the little gasket that goes in between the oil cooler and the
engine.
Of course, you can't necessarily fix that unless you take off the oil cooler.
But generally speaking, it's something very simple as an O-ring.
Now, assuming you found where that oil leak is, and it is actually just the oil cooler
gasket, I would go to 1aauto.com and buy myself a new one.
Another check engine light.
Sometimes when you pull your check engine light, you're going to find a code that comes
up P0420.
When this happens, generally speaking, what it's meaning is you have an issue with your
catalytic converter.
There's going to be some symptoms that you're probably going to notice either before or
maybe even after the check engine light turns on.
Let's get into it.
Now, one of the first symptoms that you may or may not notice is probably going to be
a lack of power and poor fuel economy.
The reason why I said you may not notice it is because it's probably going to start off
kind of slow.
It's not just going to go from plenty of pep to no pep.
More than likely, it's going to be just kind of, like, an overall, maybe over a couple
months, or even who knows?
A year.
But what's happening is is actually the inside of the catalytic converter, the internals,
they have an issue that's going on with them.
Generally speaking, they either clog up and then break up, or something happens where
it just kind of breaks up inside and you have little pieces rattling around inside there.
When that happens, the catalytic converter is going to work very inefficiently.
If the catalytic converter is clogged up or if the honeycomb on the inside has spun a
little bit and it's blocking the exit for the exhaust to come out, it's going to, of
course, cause a lack of power because your engine needs to be able to breathe in and
needs to breathe out.
So, something else that you might notice is a strong or even faint eggy smell in the air.
And that kind of seems a little bit weird, but more than likely, it's probably coming
from your catalytic converter.
And one last thing that you may or may not notice is excessive heat coming from the catalytic
converter on this vehicle.
If it gets plugged up, of course, it's going to have restriction and the restriction is
going to cause excessive heat.
If you were to take a peek at that catalytic converter, it might even be glowing red, in
which case, it's going to be super unsafe, especially if you happen to park near anything
that might be flammable or meltable.
Okay.
So, fixes for this.
Unfortunately, we will be replacing that catalytic converter.
And I do understand that more than likely it's extremely expensive for most people,
but it is something that you don't want to put off.
If you have a code that says P0420 on it, you need to get your catalytic converter checked
and/or replaced.
The next thing I want to talk about on these vehicles is still located under the hood.
And I know we've been spending a lot of time over here, but that's just the way it is sometimes.
If you were to look at the top side of the engine, you're going to see your air intake.
Comes right up along here, and you've got this right here.
That's going to come right down.
It's going to connect onto the engine.
In between those two pieces, there's going to be a gasket.
Unfortunately on this, it's very common for the gasket, extremely close to where the cylinder
4 is, goes bad.
When that happens, your vehicle is going to be drawing unmetered air into the engine.
So, what I mean by that is as your vehicle is running and you step on the gas, it's supposed
to be drawing air up through your intake and then up through here.
It goes right past the mass airflow sensor, which meters how much air is getting pulled
through, and then it lets the computer know how much fuel to pull, and that way there
you can have a perfect running engine.
If you have a leak up past the mass airflow sensor, the mass airflow sensor doesn't know
about all that air that's going in up there, right?
That's kind of just sneaking in.
Another thing to think about is it's dirty.
It's dirty air.
It's not filtered from the air filter.
So, of course, this is going to be a very big problem.
Okay.
So, fixes for this would be to replace the intake gasket.
Of course, when you're going to be doing that, you're going to be taking all this apart.
So, you would want to clean everything correspondingly as you go down the line.
You have your air filter, your mass airflow sensor, and, of course, the throttle body.
Now, the next thing I want to talk to you about is located right underneath the backseat.
If you were to come right back here and pull on these little tabs, you can pull out your
backseat.
Under there, you're going to have this little cover.
Go ahead and twist those locks.
And then right under that is located the fuel pump, and that leads us to the next issue
we're going to talk about, which involves fuel starvation.
Now, some of the things that you're probably going to notice for this would be fuel starvation.
Maybe you step on the gas and the vehicle just doesn't want to go because it's not getting
enough fuel pressure.
Maybe you go to start the vehicle, and it just crank, crank, crank, crank, crank, crank,
crank, crank, crank, crank, crank, crank, cranks, but it doesn't actually turn over.
Once again, it's not getting enough fuel pressure, so it's not going to start.
Or maybe you get inside your vehicle and you go to start it and you start smelling a little
bit of a fuel smell.
Why is it coming from inside the vehicle?
Well, because it's right underneath the backseat.
Now, if we're talking about the issue of fuel starvation/not necessarily wanting to start,
you would probably look right around here.
Right where this connects onto the fuel pump, a lot of times the O-rings in between here
and here goes bad or even this one goes bad.
That's not necessarily super common, but you could also have a leak where the fuel pump
actually connects to the fuel tank.
There's also an O-ring in there.
If any of those are dry and brittle, they're going to obviously cause an issue.
If you're talking about the fact that the vehicle just crank, crank, crank, crank, cranks
and doesn't actually necessarily start, then I would probably go right about here.
You would take off your electrical connector and then you would test for polarity from
all your wires.
You want to make sure you're getting power and ground as you should.
If those are working as they should, and there's no corrosion inside the connector, my next
step, of course, would be to replace the fuel pump, which is very common to have to replace
in these vehicles.
All right.
So, that's another top problems in the book.
If you like the video, make sure you get down there and hit the Like button.
While you're at it, go ahead and subscribe, and ring the bell.
That way there, you'll be kept up with all of our latest content.
While you're at it, why don't you leave me a comment right down there?
I'd love to know how you felt about the video.
Thanks.
Thanks for watching.
Visit 1aauto.com for quality auto parts shipped to your door, the place for DIY auto repair.
And if you enjoyed this video, please click the Subscribe button.