Beware of Jeep 4.7 engine problems. This engine struggles to keep working for decades without problems. Blown head gaskets and overheating are common issues you may experience.
As the engine plays a crucial role in your vehicle, replacing it can be super expensive when it gets damaged.
You can prevent this if you catch these symptoms early on. That said, we’ve gathered the most common problems among the Jeep 4.7 engine and how you can fix them.
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Top 8 Early Warning Signs of Engine Failure
You will come across many online discussions about the Jeep 4.7 engine and what could have gone wrong with it.
To make things easier, we’ve narrowed down the most common problems you’re likely to run into. So, here they are:
1. Blown Head Gasket
The most common problem you’ll face with your 4.7 engine is a blown head gasket. When the head gasket goes bad, there are many ways to tell there’s something wrong with it.
That said, below you’ll find how you can tell if the head gasket must be replaced:
- The vehicle isn’t running right. If the head gasket failed, the engine would have a hard time running.
- If you’ve been driving and noticed a massive amount of white smoke coming out of the exhaust, it’s safe to assume you have a blown head gasket.
- Check the color of the oil. To do this, drain it out. If it has a milkshake color to it, then it’s a clear sign that coolant is mixing with the oil. This is pretty bad, and it’s a clear sign the head gasket was poorly installed.
- Overheating is also a prevalent cause of blown head gaskets. If your engine is overheating, it’ll destroy the cylinder head. As a result, it’ll damage the head gasket.
This is one of those things drivers hate to hear about. Replacing the head gasket is a very intensive and expensive job.
Installing a brand-new head gasket can cost anywhere from $1,000 all the way up to $4,000. Nonetheless, get this addressed immediately before things get worse.
2. Dropped Valve Seats
The Jeep 4.7 engine is known for dropping valve seats. Dropped valve seats are a clear sign of Jeep 4.7 motor problems.
Generally speaking, this happens because there are air pockets in the cooling system.
Typically, you would get rid of that by bleeding the air out of the cooling system.
However, if this is not done correctly, you’ll get high temperatures in the valve seat as the heat from the air pocket moves around.
This is going on back and forth all the time. With that much air going on inside, it’s no surprising the valve seats drop.
As expected, you’ll have to replace the damaged valve seats to fix this issue.
That said, here is how you can determine if the valve seats dropped on you:
- If your vehicle is rattling like crazy, it’s safe the assume it dropped a valve seat.
- When valve seats drop, it’ll cause the car to run rough, and sometimes the engine might stall.
- The check engine light goes on and off pretty quickly.
The average cost for this job can go anywhere from $1,100-$1,800. But if you choose to rebuild the valve seat, expect to pay $450.
3. Yellowish Foam On Dipstick
Another thing that can mess up your vehicle is a faulty PCV system. If the unit goes bad, it’ll turn your engine oil into a rather disgusting color.
If you’ve recently pulled up the dipstick, you probably noticed the yellowish foam on it.
Sometimes, however, this could be nothing. For example, it could be water that got into the oil during a cold start.
Once the engine has reached the right temperature to operate, the water will build up as time goes by.
If you want to rule this out, consider the following symptoms:
- If you’re going down the road and noticed clouds of smoke behind you, it could be a faulty PCV valve. When it goes bad, white smoke will come from the tailgate.
- If your vehicle is running rough, this could be an early sign there’s something fishy going on with the PCV valve.
- When the PCV valve goes bad, the check engine light should start to appear on the dashboard to let the driver know there’s something wrong with it.
To fix this issue, simply replace the PCV valve. Luckily replacing one of these is super cheap. At most, you might pay $40 for the replacement and $80 for the job.
4. Jeep 4.7 No Compression
Getting poor performance when driving? Well, you might have a broken valve spring.
When this part of your vehicle goes bad, it’ll cause misfiring, and your car will run roughly as the engine speed goes up.
The car might start fine, but the more you drive, the worse it’ll perform. What’s more, when you have a cracked valve spring, your car will sound like it’s dying out.
No compression is a severe problem and should be addressed immediately. If you let it go by, chances are this issue will destroy your engine.
5. Rough Idle
Many issues could lead to a rough idle. So, it’s hard to tell what could be the culprit. However, let’s narrow down the possible problems for the sake of convenience.
- Check the fuel injectors. If the injectors are clogged, the injectors will not get as much fuel as needed, resulting in a rough idle.
- Check that the intake valve in the cylinder is seating correctly. If it is not seating correctly, you’ll have a hard time starting up the engine.
- Damaged spark plugs will not produce as much power as intended. This translates to rough idle. So, make sure they’re still in great shape if you have not changed them recently.
These are the most common reasons why the Jeep 4.7 engine might have a hard time working as intended. Consider checking out those parts of your vehicle before going to the dealer.
6. Jeep 4.7 No Oil Pressure
Is your oil pressure fluctuating while driving, and sometimes the oil pressure gauge decides to show no pressure whatsoever, and then the “check gauge” light comes on?
Well, you might have a bad oil pressure sensor.
No oil pressure is a very concerning problem as you have no way of knowing when you’re running low on oil.
As a result, your vehicle will not work correctly. Luckily, this can be easily fixed, and it’s pretty cheap to replace an oil pressure sensor.
That said, here’s a small summary of some of the most common problems you’ll run into if the oil pressure sensor went bad:
- When there’s something wrong with the oil pressure sensor, you’ll get the oil pressure light on the dashboard.
- Bad oil pressure cannot measure your oil pressure. When this happens, the gauge will show no pressure.
- Another symptom of a bad oil pressure sensor is that the oil pressure light will repeatedly blink as you drive. If you’ve run into this problem, chances are the oil sensor failed.
If you want to know more about low oil pressure on the Jeep 4.7 engine, we suggest checking this video out:
7. Lack of Acceleration
A common problem among the Jeep 4.7 engine is the lack of acceleration. If your car takes forever to get to speed, it’s most likely a damaged spark plug.
If the spark plugs get dirty or damaged, they can mess up your engine, so it takes a lot of time to speed up.
Fortunately, replacing the spark plugs is a simple job and can be done by anybody.
Better yet, getting a set of spark plugs is pretty cheap for the Jeep 4.7 engine. For example, you can new spark plugs for roughly $35-$40.
8. Overheating Engine
A leaky radiator can cause Jeep 4.7 engine problems. When the radiator is leaking, it’ll overheat the engine as the coolant going through the radiator’s tubes have no way of cooling down the engine.
If this issue is not fixed, it will destroy your engine.
However, if the radiator is leaking, you will also experience other symptoms. Here is a list of common symptoms related to a leaky radiator:
- Crawl underneath the vehicle. If you see a massive puddle of fluid, it could be related to the radiator.
- Noticed white smoke coming out of the tailgate? When this happens, it means that coolant is being burned up inside as coolant is dripping out of the radiator core.
- If the coolant is not at the proper level, you might have a leak somewhere.
To fix this problem, you would typically replace the radiator, and that’s about it.
But, if the radiator is still in great shape, you could use the bar’s leak sealer. Most of the time, it’ll seal the leak perfectly.
Using a leak sealer is pretty cheap and straightforward. That said, here’s how you can use it on your car:
- Take the radiator cap off, and then pour the sealer inside. After that, drive the car around for a couple of hours. Finally, let it sit overnight.
- Once that’s done, check it out to see if the coolant is no longer leaking.
Damaged Jeep 4.7 Engine Replacement Cost
If you’ve carefully analyzed all the problems we covered above and determined that there’s nothing you can do to fix your engine, then you’ve got two options here.
You could either rebuild the engine or get a new one.
If you choose to rebuild one, expect to pay anywhere from $2,000 to $3,500. That is, including labor and the components to rebuild the engine.
Also, when rebuilding an engine, do not cheap out. Cheap aftermarket repair kits should not be used for this job.
They’re not as durable, and there’s a high chance the engine will fail after some time.
Your second option is to get a brand-new engine. If you choose to get a new one, it will cost you about $4,000-$7,000.
This price might also increase depending on many various factors such as location and the dealer.
Frequently Asked Questions (FAQs)
For more information about the Jeep 4.7 engine, refer to the section down below:
Is the Jeep 4.7 a good engine?
Many drivers have different takes on the Jeep 4.7 engine. You might hear some people argue that you should stay away from it and that you’re better off getting any other engine.
But at the same time, you’ll hear drivers say that they’ve never run into any significant problem.
What should Jeep oil pressure be?
The oil pressure gauge must be 10 PSI. Anything below that is unacceptable.
If your oil pressure gauge drops to 0 when coming to a stop, we suggest checking the oil level and the oil sensor.
How long will a jeep 4.7 V8 last?
It really depends on the driver and how well maintained it is.
However, let’s assume that you’ve carefully maintained it all this time. You should expect it to last up to 100,000 to 120,000 miles.
Is it better to replace head gasket or engine?
You’re better off replacing the head gasket. That is, if both the cylinder head and engine block are still in great shape. If that’s not the case, you’ll have to replace all of them.
Conclusion
As we covered above, there are many Jeep 4.7 engine problems. Fortunately, fixing some of these issues is child’s play.
However, some of these problems can be quite hard to track down. As a result, your mechanic might spend a lot of time until they can find the culprit.
You should also know that the engine problem you’re experiencing right now could be caused by many of the issues discussed above.
So, it wouldn’t hurt to go through every single step we covered above.
That said, we hope you now have a better understanding of all the things that can damage the 4.7 engine.
