Top Common Engine Problems 1984-2001 Jeep Cherokee SUV

In this video, we're gonna talk to you about the most common problems I found with a 4.0 liter Jeep Cherokee.

I wanna start by saying, I like the 4.0, I think it's a great engine. It's hardy. It has its problems, but every car does, but it also has its benefits. But we're talking about problems mechanically, and these are easy fixes. So, you know, if you take everything in consideration, 4.0 is really a hardy vehicle. Common problem though first, I'm gonna start with the crank sensor. I'm not gonna go past that. You have a Jeep with a 4.0 in it, and you're just driving along and all of a sudden, it just, you might go into the store if something come out and it just crank, crank, crank, crank, crank it won't start, it's gonna be the crank sensor, 90% of the time. First thing to check, first thing to test.

Unfortunately, it's also not so easy to get to. It's over there and when all I can say is make sure you get a really good one, because it's gonna take you some time to put it in. It's not like hours and hours. It's just a little tedious to get to, but it fixes it almost every single time. I think it's because it heats up. When they mounted it in between the bell housing on the block and it's a sensor. So it's not, it doesn't like the heat contrast and all the water cooling it down. It's just an electronic piece that they put out in the elements that shouldn't probably be there, but that's a common problem. Easy to fix.

Another real common problem with the 4.0 liter is exhaust manifold cracking. The factory one has the six outlets coming out and they weld them into V points, real sharp, V points like this. So with the flex of the engine, where that V point matches that weld ends up splitting eventually. So they updated it with two exhaust flex pipes on either end and the other ports come out and they have their own individual weld in the pipe. You can look up images. It's pretty cool to just do a little homework like that and see them, but that's how they solve the problem. And it actually lasts a lot longer. Doing the job, several hours, a couple hours, because you've gotta replace that exhaust gasket. And I strongly recommend make sure you get one that's a metal one and not a carbon. The carbon one seems to break down a lot faster and it's not worth it because the intake is mounted with the exhaust manifold. So you don't wanna deal with...you just want to do it right. Get it done.

Next major problem, you all know what if you have one is oil leaks. So the first one I wanna talk about is the oil filter housing, easy repair, easy, easy, easy, common. Buy one gasket, buy five, do it every two years, two a year because that's what it's gonna be. But it's so easy to do that it's not even worth getting aggravated about. It's just, if you like Jeeps, you're gonna love it. And it's an easy job to fix. Next one that I wanna talk about is the rear main seal. And you can see ours is dripping right there. Comes back through the bell housing, new oil pan has been done on this. They did the gasket, of course, and then it's still dripping out of the rear main. Good way to diagnose the rear main would be to run the vehicle, make sure you have a clean spot, run it, shut it off. And as soon as it shuts off, it should drip.

Now, if it's oil pan, it's just gonna leak when it's running, when it shuts off, it won't leak as quickly. Mostly when it's running and the oil is being circulated. The opposite is with a rear main. So the real common they tear up. So you have to make the oil pan down and you have to get to that rear main seal, take the cap off, the cap and replace it. So the last one I wanna talk about is exhaust valve carbon buildup. Real common on these. They actually had a technical service bulletin on it that Chrysler would a Jeep/Jeep would take the valve cover off. You put compression into the cylinder and you'd turn the timing and you undo the valve spring and you take the exhaust valve and they would turn it 180 degrees. That's because where the seat in the head meet there would be a carbon buildup and they would turn it. Yeah.

Assemble it and go onto the next cylinder then they would do a carbon clean. So that way the carbon clean could actually get in there and clean it up. And what you'll find is a misfire shake, a loud ticky noise in the upper end. So you hear tach, tach, tach, constantly in the upper end in my...it's going to shake too like a misfire. You might end up doing coil sparkplugs and the misfires still there. You can do a leak down test if you have that tool and that way you could confirm that you had an exhaust valve leak. But it's pretty common because of these valve covers, it'll get gunked up. You do a real regular maintenance oil change and use a good oil, you probably could avoid this whole thing and talk to your because you want the detergent in there to clean those valves.

Other than, that's the way I would maintain it, keep it from happening, but it could happen eventually happen and these things will just keep going. They won't die. It's just could be annoyed and high gas mileage, which you don't want. So I hope you enjoyed this video. If you are not a subscriber, please subscribe. Don't forget to ting that bell because it turns on all your notifications so you won't miss any future videos.