Top 5 Problems Lexus ES300 Sedan 3rd Generation 1997-2001

Hey, friends, it's Len here from 1A Auto. So, today in the studio, we have another top problems for you. This one's gonna be on a 3rd Generation Lexus ES300. Let's get into it. Okay, friends, for our first problem, we're gonna talk about a clogged or even faulty IAC valve. Firstly, what is an IAC valve? Well, IAC valve essentially stands for idle air control valve. Now the IAC location is gonna be located underneath your throttle body, underneath this area right here. And what it's basically supposed to do is it's supposed to regulate the amount of air getting put into your system to make sure that that way there, you can achieve the perfect idle, especially under cold conditions. Now, that's not to be confused with the throttle body. The throttle body has a completely different job. That's essentially supposed to regulate the amount of air getting drawn into your engine under acceleration. Some of the symptoms that you might happen to find if you're having an issue with your IAC valve might potentially be lower erratic idle speeds. It could also potentially be poor fuel economy. It might also be, in the cold, a hard start or even once it does start, a very erratic idle.

Now, if we're gonna talk about fixes for this, for me, it really makes sense to go ahead and take it apart and try to clean it out. Typically, what you would probably find if you were to go ahead and remove the IAC valve from the intake system, there's a lot of black crunchies inside there. That's gonna be carbon buildup. This is gonna be very common. The carbon buildup, of course, can be easily removed using a detergent. You just wanna make sure that you use the proper stuff and not necessarily brake cleaner or anything like that. Also, when you do it, you wanna go ahead and use some kind of soft-bristled brush, like maybe an old toothbrush, but definitely don't use a new toothbrush. Other than that, make sure that while you're cleaning this, you're doing it over a mat of some sort or at least some sort of collection receptacle because any of the chemicals that are gonna be coming out of there, of course, are gonna be hazardous to the environment.

So you took a peek at that IAC valve and maybe when you were looking at it, you seem to think that it has a lot of that carbon buildup on there. Something to think about is if there's a lot of carbon buildup on your IAC valve, there's probably a lot inside of your system over here as well, such as maybe your throttle body or anything of the like. So, of course, take a peek at all that and clean everything as you go. Now let's go with the assumption that maybe you did try to clean it out and for some reason, your car still has the same condition. Maybe you're even still getting a check engine light that comes up on your dash saying you're having an issue with your IAC valve. If that's the case, well, I guess you're just gonna have to go ahead and replace it.

Now, for our second problem, we're gonna talk about O2 sensors. Now, your O2 sensors are gonna be located on your automobile's exhaust. And on this one, this is a V6, so essentially, it's gonna have two banks. There's gonna be a forward bank that's gonna have three cylinders and there's also gonna be three cylinders on the backside of the engine. Each one of those banks is gonna have a manifold and, in turn, is also gonna have an O2 sensor in it. So symptoms of a bad O2 sensor. Well, you're probably gonna get a check engine light, right? It's gonna pop up on your dash and you're gonna wanna try to figure out what it is. When you pull the code, it's either gonna tell you that you're having an issue with one of your O2 sensors, multiple O2 sensors, and even commonly, with these codes, you're probably also gonna see one that makes you maybe believe you have an issue with your catalytic converter. You just wanna be careful in this instance because, of course, if you're having an issue with an O2 sensor, it might lead you in the direction of replacing something a little bit more costly. So just keep that in mind.

A couple other symptoms that you might happen to find if you're having an issue with your O2 sensor might potentially be more pollution coming out of your tailpipe. Maybe you've got your car running, you happen to walk around back, it smells a little funny and you're noticing a little bit more smoke coming out that tailpipe than normal. The reason behind that is is because well, if your O2 sensor isn't communicating with the brain of the car and saying that, "Hey, there's an issue," well, the brain just really doesn't know. And then, of course, to hit you in the wallet, poor fuel economy. Now, of course, if we're gonna talk about fixes for bad O2 sensor issues, you're gonna wanna diagnose the issue first. If you find that you're having an issue with maybe one of your upstream O2 sensors, maybe you can just go ahead and replace just that one O2 sensor. But what you might happen to find is in the near future, you're probably gonna have to replace another one and then, of course, another one.

Now, for problem number three, we're gonna talk about worn piston rings. Now, your piston rings are obviously gonna be located on your piston, and, of course, they're gonna go in between the piston and the cylinder walls of your engine. Some of the symptoms that you might happen to find if you have worn or damaged piston rings could include may be white or even gray smoke coming out your tailpipe out back there. If you see smoke that looks like that, that means that these rings are worn down, and, of course, they're not sealing the way that they're supposed to. Other than that, you might happen to notice oil consumption, especially if this lower ring right along here gets worn down, that, of course, is the oil ring right there. You might happen to notice low power or even poor acceleration or even just overall bad performance. And if we're gonna talk about common reasons why you might actually have issues with your piston rings, well, it could essentially come out to the fact that maybe you're just not keeping up with your maintenance the way that you're supposed to. If you go beyond that 3,000 miles, maybe 5,000 or even 7,000, well, of course, the oil could potentially be a little low, in which case, the pump won't be able to lubricate things the way that they're supposed to. Other than that, maybe the oil that's in there just gets a little bit nasty and gunky over time. Any of that stuff that's kind of floating around in and throughout the system could potentially wear down these seals and then, of course, you're gonna have issues.

Now, as far as fixes for this, it's not necessarily something that I'm gonna wanna do in the driveway. Is it very hard? Not really, but it is time-consuming. What you're gonna have to do is tear apart your whole engine so you can get to your pistons, remove them, and then, of course, replace these rings. There's gonna be some other things that you need to know. Of course, if you were to switch these rings around and mix them up, that could potentially be an issue, and, of course, there's gonna be a lot of torque specs and different measurements that you're gonna want as well.

Now, for our fourth problem, we're gonna talk about ignition coils. So, to find your coil, you're gonna go ahead and get underneath this cover, and then, of course, here's your ignition coils. So now where I showed you you're gonna be able to find three of those ignition coils, but the other three are actually gonna be located on the backside of the engine underneath your intake. Now, the job of the ignition coil is to send power from the actual computer down to that spark plug, which in turn is gonna ignite the combustible materials inside of your combustion chamber. If you were to have an issue with one of these coils, essentially, what could happen is you finally have poor fuel economy, you might happen to notice that you have poor acceleration, a misfire coming from the engine, or even, of course, that pesky check engine light that loves to come on on the dash for some reason.

So, now, we're gonna talk about some fixes for this. It's a six-cylinder, it has six coils in it, so that's something to pay attention to. If you were to have a little coil and you go ahead and pull the code for your check engine light, assuming you have one, it might tell you that one cylinder has got a misfire or even multiple cylinders have a misfire. That's gonna be all things that you wanna pay attention to because we wanna make sure that we diagnose in the proper direction. If for some reason your scanner says that you have an issue on cylinder 1, what I would wanna do is just find cylinder 1, remove the coil from that, and then I'm gonna find another cylinder that's on the opposite side of the engine and then replace it with that coil. Basically just doing a swap between the two cylinders. After that, I'm gonna go ahead and plug everything back in and then, of course, clear the light and take it for a road test.

What I'm doing right now is I'm trying to see if there's an issue with the coil and I'm trying to see if it's gonna move along to the cylinder that I moved the said "to be bad coil to." If, of course, the issue did happen to move, you still have a misfire but now it moved to the other cylinder and it's not on the cylinder 1 anymore, well, then you know that you had an issue with the coil. If for some reason the misfire stayed in that one cylinder, well, then that's probably telling you that you got another issue, more than likely, the spark plug. When it comes time to replacing these, you could replace just one, but overall, it really kind of makes sense to replace all six of them. They have electronic components inside of them and, of course, anything electronic just goes bad over time.

For our fifth problem, we're gonna talk about vacuum leaks, but this one comes down to user error. Now it's a very common thing on every automobile to go ahead and check your air filter. You're gonna get under the hood and you're gonna go ahead and find that air filter box. Go ahead and pull on the clips, and then, of course, you wanna lift this up and then try to take a peek. It doesn't come up very far, though. Why is that? Well, if you come on the backside here, you're gonna see that there's a vacuum hose. So, as you can tell, I can barely get the air filter out of there if I could. So what am I gonna do next? I'm probably gonna try to take off that vacuum hose. Go ahead and take it off of there. I check my air filter, it's dirty. I go ahead and I replace it, of course, and then I put it back together. And what I realize after I go ahead and start it back up is now I have a running condition and a check engine light. So, now let's go with the assumption we did a little bit more work and we took all this apart all the way up to the intake. Well, as you can see, there's a whole bunch more vacuum hoses on this thing that could potentially be forgotten and get put back on. There's one right here. This one's always easy to miss. And then, of course, if you were to look along the bottom side or anything like that, there's gonna be a lot of other hoses and things that you can forget. If you were to leave any of these loose, you would potentially be causing a vacuum leak, and if you have a vacuum leak, then you're gonna have a running issue.

So, for fixes for this, if you have a check engine light on, you're gonna wanna go ahead and pull that code, see what it says. If it's telling you have a vacuum leak, go ahead and inspect all the vacuum lines that are on your intake system. This is gonna be a very common area for somebody to leave things off. And if you did happen to leave something unattached, just go ahead and plug it back in and then clear that check engine light.

Okay, friends, so those are some of the top problems that we've come to find on a 3rd Generation Lexus ES300. This is a great car overall. It's got almost 200,000 miles on it, still a baby if you ask me. Every car has its problems. Maybe you've got a car of your own with problems of its own. If so, tell me about it in the comments section below because I always love to hear from you. If you liked the video or you learned a little something, go ahead and smash on that like button for me. It'll mean the world. While you're at it, go ahead and subscribe, ring the bell, and share our videos. That way there, you and your friends can be kept up with all of our latest content. Thanks.