Like other engine rebuild kits, getting jeep 4.0 engine rebuild kits can sometimes be complicated than working on the engine itself.
Deciding to either rebuild or replace your faulty engine might even be more complicated.
However, identifying the exact causes of your malfunctioning engine is the first step here.
Worn out bearings or faulty piston rings can cause engine malfunctions. Poor engine maintenance is another factor that does this too.
So, a bit of knowledge is needed before taking any step on fixing your engine.
Let’s start with discussing what jeep 4.0 engine rebuild kits are.
What is Jeep 4.0 Engine Rebuild Kits?
When we say jeep 4.0 engine rebuild kits, we refer to those engine parts needed to rebuild your jeep engine.
Besides, rebuilding your engine might be either due to a need for a performance upgrade or a problem caused by faulty engine parts.
Either way, the rebuild involves the replacement or modification of some parts of your jeep engine.
As a result, it’s essential to identify the faulty parts you will be replacing. It is these parts that will form the components of your engine kit.
Moreover, engine rebuild is a bit easier since manufacturers now go through the stress of putting the needed components together for you. Hence, the name “kit.”
These engine rebuild kits commonly include plugs, gaskets, engine bearings, seals, and piston rings. Sometimes the engine kit might also contain a camshaft, valvetrain, and pistons.
However, these are not what will ALWAYS be in every engine rebuild kit.
The kit you will be getting is based on the specifications you give the manufacturer or kit seller.
This kit includes preferred bore sizes or camshaft length.
You can confirm the exact sizes you will be needing by disassembling the engine to measure important details.
You can ask your mechanic to help you with that.
It is only after doing that it’s best to make an order for an engine kit. Ordering for a kit is like buying in bulk. So, you can be sure to get some discount as well.
Which Components are included in the Jeep 4.0 Engine Rebuild Kits?
While the pieces in individual rebuild kits may vary, the following components are commonly found in an engine rebuild kit.
- Piston & Freeze Plug set
- Main Bearings & Piston Ring set
- Rod & Cam Bearings set
- Lower & Head Gasket set
- Timing Chain kit
- Oil pump & Lash lifters
Where to find Jeep 4.0 Engine Rebuild Kits?
Check trusted online stores. By this, we mean those stores that have an excellent record of customer feedback.
Any store you will be picking should provide an adequate description of the engine kits they have for sale.
You should be able to see the picture and specifications before making an order. They should also have a team that you can always talk to and give your preferred specifications.
How Much Does It Cost to Get Jeep 4.0 Engine Rebuild Kits?
Generally, the cost of getting jeep 4.0 engine rebuild kits is not something that is fixed.
If you are looking for just a re-ring kit and main bearings, you can hope to see a rebuild kit for about $200.
However, going for a full Master Rebuild kit can be more expensive and priced at around $350-$900.
How to use Jeep 4.0 Engine Rebuild Kits?
Getting one of the jeep 4.0 engine rebuild kits is one thing. Knowing how to use it is another.
Rebuilding an engine for the first time can be very challenging. So, we will be discussing some of the steps in using that kit to rebuild your engine.
1. Remove the Engine
We expect that you have removed the engine before ordering the rebuild kits.
In case you haven’t done so, you might consider using an engine hoist (or crane) to pull out the engine.
This should be after you have disconnected it from all its external components or electrical connections.
2. Disassemble the Engine Block
Before you go further with the disassembly, ensure you are marking the different parts and taking clear photos.
Ensure you do this to avoid getting confused during recoupling.
So, for the disassembly, the first step is to inspect the engine parts for obvious faults or sign of cracks or worn out parts.
It would be best if you also try looking out for signs of overheating or loose plugs. Just check for anything out of the norm.
The same applies to the external engine parts like the pulley belts and alternator. Ensure there are no loose parts.
Cylinder bores are also essential too, and you should carefully examine them for wear and tear possibilities.
The same goes for the piston and rod assemblies as well. Rebuilding is a process that can take a few days, so take your time. There is no need to rush.
That being said, it is important to also check out other vital external parts like the crankshaft. Check for dirt and pay attention to verify that the dimensioning is correct.
3. Disassemble the Cylinder Head
The aim here is to remove the valve springs. Firstly, use the springs compressor to compress the valve springs and make them easier to remove.
You should also remove and examine the valve head for carbon dirt. Try checking out for overextension of the springs or flatness. Do not also forget to lubricate the valves before putting them back.
4. Reassemble the Engine Block
Now, we are almost concluding things, and we will be working backward. So, the pictures and labels will come in handy at this point.
Before returning any part to its position, make sure you’ve thoroughly cleaned it. When possible, wash and dry-air the parts. Do the same for the engine blocks as well.
You should also remember to condition joints such as those in your camshaft and crankshaft by lubricating them with oil.
Furthermore, carefully and calmly install and align the timing marks at the top dead center. Remember to set the degree wheel correctly too.
New pistons, piston rings, and gaskets should also be used. Moreover, care should be taken to correctly install the gaskets while the piston rings should be perfect.
5. Mount and Test the Engine
Do not panic. Just follow the same steps you took in removing the engine. The only difference is that you are now working in reverse order. Also, ensure there is sufficient engine oil and antifreeze.
You should also confirm that the engine is perfectly recoupled. The next step is to start the engine now and see if it’s working.
It’s best to refer to the manual for better performance and safety and carefully follow the start-up procedures.
Are you feeling confident about the process?
Pros and Cons of using a Rebuild Kit
We will be taking a quick look at the pros and cons of using a rebuild kit for an engine rebuild.
- Economical due to lower unit costs
- Guaranteed Compatibility of engine parts
- Enhanced Performance of Engine
- You are buying in bulk and can end up buying parts you do not need
- It takes time to order or make a purchase sometimes
5 Best Jeep 4.0 Rebuild Kit Reviews
01. DNJ EK1123AM
This new DNJ EK1123AM is suitable for 2001-03 jeeps, Grand Cherokee, Wrangler, and Cherokee 4.0L L6 OHV.
The rebuild kit weighs 26.7 pounds, and its components include piston and piston ring sets, main bearing set, rod bearing set, head, and lower gasket sets.
Other pieces present in it are brass freeze plugs, cam bearings, timing chain kit, oil pump, and lash lifters.
Identification of the components will not be a problem because all pieces have been correctly labeled. Also, interchangeable parts have been specified.
Except stated otherwise, the components are all STANDARD sizes by default. You will have to make a custom order to get oversized ones.
Such custom orders should have the Year, Make, Model, and Engine size for precision.
Besides, WARRANTY is available for all the parts/components for the first 12 months or the first 12,000 miles distance, depending on whichever occurs first.
02. DNJ EK1126M
The DNJ EK1126M Master Engine Rebuild Kit is still new and is suitable for use in 1996-98 Jeeps/Cherokee, Grand Cherokee, and in Wrangler 4.0L L6 OHV naturally aspirated engines.
The kit weighs 28.1 pounds and includes head and lower gasket sets, main and rod bearing sets, piston and piston ring sets, and oil pumps.
You can also find the brass freeze plug set, timing chain kit, lash lifters, and cam bearings in the engine rebuild kit.
As stated on Amazon, all the parts or components have been properly labeled to enable easy identification.
In addition, all the components of the kit come in STANDARD sizes except a custom order is made.
To do this, you will have to clearly state the Year, Model, Make, and Engine size to obtain a perfect match.
Also, note that WARRANTY is available and covers ONLY the first 12 months or 12000 miles of distance covered.
03. DNJ EK1123M Master Engine
The DNJ EK1123AM is new and similar to the first rebuild kit we discussed here.
This Master Engine Rebuild kit is for 1999-2000 engines while the former is for 2001-03 engines. Therefore, both are suitable for the same engine types.
The pieces in this 99-00 engine rebuild kit include cam bearings, oil pump, camshaft bearings, lash lifters, and brass type freeze plugs.
Simpler pieces like main and rod bearing sets, piston and piston ring sets, head gasket set, and lower gasket set are also included in the rebuild kit.
Besides, piston clips are NOT included, so you will have to get that yourself.
With a weight of 26.7 pounds, all the pieces in this rebuild kit come in STANDARD sizes except otherwise requested.
The different pieces have also been labeled for proper identification.
As expected, WARRANTY is available and is for ONLY the first 12 months of use or 12,000 miles.
04. DNJ EK1126M Rebuild Kit
Brand new DNJ Master Engine Rebuild Kit for 96-98 Jeep/Cherokee, Grand Cherokee, Wrangler, and 4.0L L6 OHV naturally aspirated engines.
The kit’s weight is 28.1 pounds, and some of the pieces in it include lash lifters, piston ring set, piston set, timing chain kit, rod, and main bearing sets.
More pieces in this engine rebuild kit are freeze plug set (brass), head and lower gasket sets, cam bearings, and oil pumps.
Also, all the pieces or components in the kit come in their STANDARD sizes.
There is a need to make a custom order and state the Year, Model, and Engine size if you need something oversize.
Some of the pieces are also interchangeable, and they have been indicated for easy referencing.
Lastly, WARRANTY is very much available and covers the first 12 months or 12,000 miles of use.
05. Master Engine Rebuild Kit
As of the time of writing this review, this product was unavailable. However, this Enginetech’s Master Rebuild Kit is a good value for money.
It is good for use in 2005-06 Jeeps with a 4.0L L6 Wrangler engine.
The rebuild kit components are high quality and include a full gasket set, premium piston rings, pistons, and timing set.
The other components included are the main/rod/cam bearings, oil pump, lifters, camshaft, valve stem seals, and freeze plugs.
In addition, the kit weighs 1 pound, and the sizes of the pistons/rings are standard 020, 030, and 040.
The dimensions are also standard for the rod/main bearings and include 010, 020, and 030.
During the order, you can request pictures and also specify the sizes you will be needing. In case you got an unwanted size, a return/exchange is possible as long as you have not opened the seal.
The sellers are open to any other question you have and promise a response within one business day.
Common Issues of Jeep 4.0 Engines
The more you use a particular engine, the more you notice some faults that are more likely to occur.
For the jeep 4.0 engines, the following are some common issues the 4.0 engine users experience.
- Cracking manifolds
- Leaking Oil Adaptors
- Engines become noisy with time
Maintenance Tips of Engine Rebuild
If you’re carrying out an engine rebuild for the first time, the following tips might help.
- Properly label/tag all engine parts during disassembling to assist you when recoupling the details. You can consider taking pictures or short videos as well.
- If possible, let an expert help you with the engine rebuild. Precision is important!
- Take your time. A typical engine rebuild is expected to take a few days.
- Do not hesitate to refer to your engine manual for specifications if in doubt.
WH Questions of Engine Rebuild kit
What is the Difference between Used Engine and Rebuilt Engine?
While they might appear similar, there is a big difference between them.
A used Engine refers to an engine removed from a car because it is wrecked or damage occurred to one of its other mechanical parts.
Often, the vehicles involved are up for scrap or about to be sent to the junkyard.
These engines still have a useful time on it since there was no noticeable fault before pulling it out for re-use.
On the other hand, a rebuilt engine was removed from a vehicle because some parts needed replacement.
Unlike the used engines, rebuilt engines have been disassembled, cleaned, and coupled back while replacing faulty or worn-out parts.
If properly worked upon, rebuilt engines are capable of lasting you well as though nothing ever happened.
When Do I Have to Rebuild My Engine?
There are so many reasons that might make you consider getting an engine rebuild. A common one is when your car begins to release exhaust smoke fumes or fails to start on time.
This can be very unpleasant and prompt an engine rebuild.
Other reasons to consider are frequent overheating, broken oil pumps, engine knocks, worn-out engine bearings, or poorly fitted piston rings that keep falling off.
If any of these occurs, a rebuilt is recommend to avoid the faults getting worse
How Long Can I Manage a Faulty Engine?
If you have noticed your engine has issues, the best thing is to fix it immediately.
Managing a faulty engine will only lead to more complications that eventually result in expenses that could have been avoided.
For instance, loose piston rings imply that your cylinders will not be adequately sealed. Ignoring this can lead to what is called a blow-by.
So, oil begins to leak from the crankcase and burns with the fuel mixture present in the cylinder.
This is usually the cause of excess exhaust smokes from your vehicle’s exhaust pipes.
Engine Rebuild or Replacement: Which is Cheaper?
We cannot say precisely how much it will cost you to rebuild or replace that engine.
The truth is that prices vary depending on the type of car you have and what you need.
Are you looking to change the piston rings? Or is it just the camshaft? As we said, it varies.
However, the argument of cost should also involve the time it will take to fix it. If you’re a DIY person, you might want to consider how long it will cost you to fix the engine. Or how much a mechanic will charge for it.
These are part of the rebuilding costs. However, except you’re replacing almost all the parts, an engine rebuild is often the cheaper option.
Is a Rebuilt Engine as good as a Newly Bought Engine?
Yes, they are as good as the new engines and sometimes regarded as better. Usually, new engines are the standard because they are made to meet or exceed required performance levels.
However, rebuilt engines are often built with better parts to correct original engine issues.
As a result, they have no final problems and are just like the new ones. They are even covered under the engine manufacturer’s warranty.
How Long Will My Engine Last After Rebuild?
All things being equal, your engine should last you several thousand miles after having a rebuild.
The engine rebuild idea is to remove/replace the old/malfunctioning parts while carrying out basic maintenance.
So, it is expected that the engine works as much as a new one will do.
What to Look for When Choosing an Engine Rebuild Kit?
This question’s answer is quite personal because the type of rebuild kit you will need depends on your car’s type and what you want.
So, before deciding on the rebuild kit to purchase, you need to identify faulty parts and need replacement.
Then, you consider the type of performance you want if you’re going for a performance engine tool kit.
Examining your purpose is the answer here.
What Caused the Engines Problem in the First Place?
This is a crucial question that is not often asked. Before going for an engine rebuild option, it is essential to know the cause of the existing issues.
For example, overheating can be caused by broken engine oil pipes that lead to low oil levels. A clogged radiator can also cause it.
This means that rebuilding an engine without addressing the radiator issue can result in more failures.
If you do not know the cause of your engine failure, it is best to ask your mechanic.
What is the Warranty on the Engine Rebuild?
Most of the time, the warranty on rebuilt engines is usually for 12 months. It might also include some specific miles traveled.
However, the warranty does not cover issues due to poor maintenance like overheating because of low oil in the engine.
Although engine rebuild can be very stressful and thorough, it is still cheaper than getting a new engine or new vehicle.
You might also consider getting a used engine that is working instead of going through the problem of a rebuild.
However, it’s entirely up to you. While the used engine is a faster option with almost the same result, it might be close to having faults that are not obvious yet.
You may read our other review: