What Are The Most Common Issues With Ford 4.6L V8 Engine?

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The Ford 4.6L V8 is an outstanding engine. This has been said by users and critics alike. The performance to the longevity, everything is as close to perfect as things can be. It is a part of the company’s modular series, which is a popular one. Like most engines, this one also comes with a list of issues.

The 4.6 engine has four issues that have been reported to happen more frequently than the others.

  1. Problems Related To The Timing Chain
  2. Failure Of The Intake Manifold
  3. Drop-In Oil Pressure
  4. Unexpected Misfiring Of The Engine

Before diving into this article, I must assure you that all these Ford 4.6 engine problems are repairable. More on that as we progress through the article.

Without any further ado, let’s get straight into it.

The 4 Most Common Ford 4.6L V8 Engine Problems

Here I shall be detailing the four issues related to the 4.6 engine I listed above. I will be elaborating on these issues and how they can be addressed.

1. Problems Related To The Timing Chain

First, let’s discuss the function of the timing chain in an engine. The part of the 4.6 engine is responsible for controlling all the valves and pistons inside it. It ensures that these parts operate in a timely fashion so that you can get consistent and smooth performance.

Cause Of The Issue

So, what happens if a timing chain starts to cause issues? The part of the chain system that can cause issues is the plastic guides. They are very much prone to failure. The chain slaps the guides. They must handle this force. Unfortunately, they get damaged easily on the 4.6L engine.

So, what happens if these guides break? Well, the chains will become misaligned, and you will start to experience many timing issues. You also risk the possibility of irreversible damage to the valve and the piston. And the vehicle will stop working almost instantly. This is very dangerous if you are on a highway.

That is not the only thing that can cause issues. The tensioner gaskets on the chains use beads that can go bad pretty quickly. The company recommends that the whole tensioner be replaced to ensure that the issue will not occur again.

So, to summarize, these things can cause the timing chain to become loose:

  • Broken beads on tensioner gaskets
  • Breaking of the low-quality plastic chain guides
  • Wear and tear

Repair

Fortunately for all of you guys, the repair of the timing chain is possible. But the repair will not be cheap. Because the chain is buried in the engine, it will have to be taken apart.

The process is quite complicated, and then putting it back together is also a task that cannot be done at home, no matter how experienced you are.

A mechanic or a Ford dealership is your best bet. Your vehicle may be unavailable for a few days, but this is the only thing you can do to get it up and running again.

Precautions

If you own the Ford 4.6 engine and are looking to avoid this issue, the best thing is to change the oil timely and ensure that the oil used is of high quality. This ensures it will be properly lubricated.

2. Failure Of The Intake Manifold

The Ford 4.6 was the first engine of the company’s modular series. It was manufactured from 1991 to 2014, making it one of the few engines produced for more than a decade. The early versions of the 4.6 engine had an intake manifold issue. It plagued all engines that were released until 2001.

So, let’s see how it was caused.

Cause Of The Issue

Ford used a plastic manifold for the 4.6 engine. This was done to cut costs. But the company did not test it properly. The plastic surface of the manifolds was prone to cracking. The cracks compromised the integrity of the intake, and all of the coolants would dump themselves on the engine.

The 4.6engine’s lack of coolant is equivalent to keeping a microwave turned on for hours on end, with a completely restricted airflow. So, the 4.6 engine overheated and caused several problems, including warping some components, due to the excessive heat output.

The intake issues do not end there. Buyers also noticed that the temperature sensors of the intake would loosen, which would result in incorrect readings. Although this does not affect performance, a wrong reading may lead to unnecessary testing, which is also expensive.

Repair

Fortunately, for all users that had this issue, the company did offer compensation for the repair price. But it did not compensate the users for the additional damage that was done to the 4.6 engine. The newer manifold was not plastic, and there were no further complaints from users.

Precautions

So, if you are one of those users who have not experienced this yet, you are very lucky. But it does not mean that it will not affect your engine. You should, periodically, make sure that the coolant level is sufficient and the engine is working under ideal temperatures.

If you notice any inconsistency, then the intake has most probably been compromised. You must get a replacement as soon as possible to ensure that the leakage will not cause issues in the engine.

You Should Not:

  • Drive the vehicle anymore, until the repair is complete.
  • Do constant maintenance checks every few months.
  • Get the repair done from a professional.

3. Drop-In Oil Pressure

Let’s now talk about more serious issues that can frustrate many vehicle owners. The Ford 4.6 engine is also prone to a drop in oil pressure. There is more than one cause for this, and I will be listing all of them.

What Causes An Oil Pressure Drop

If the oil pressure in the engine has suddenly dropped, then the possibility is that the oil pump is damaged. It is not able to send oil at high pressure. The pump becoming faulty is a common issue in the earlier models of the 4.6 V8.

Some of you may be wondering how a pump can go faulty. Well, the company did not use the best gears when they designed the pump. They suddenly fail, and the pump starts to cause issues such as not creating enough pressure for the oil.

Diagnosis Of The Issue

Fortunately, a faulty oil pump is easy to diagnose. When the 4.6 engine does not receive enough oil to operate, then you may notice starting issues. The vehicle may either not start at all, or it would stop abruptly.

Most vehicles, including those that rock the Ford 4.6 under the hood, included a low oil pressure light. It will turn on when the engine detects a drop in oil pressure. You may also notice that the 4.6 engine frequently overheats, which is another sign of a faulty oil pump. That is not all.

A pump may rust over time, which affects its ability to pump oil at high pressure. When a fuel pump becomes faulty or corroded, the engine has to work with very little oil.

Apart from its cooling properties, the oil also reduces friction between rubbing components. Without the proper lubrication, you risk damage to the engine, which will take a heavy toll on your pockets.

So, just to be clear, you can make sure that there is an oil leak by:

  • Observing sudden stopping of the engine
  • Checking if the low oil pressure light is turned on
  • Checking if the engine is overheating quicker than usual

Repair

Let’s talk about the repair. If you caught this problem early on, the replacement procedure is fairly straightforward and will not cost you a lot. A new oil pump is cheap, and the installation process is easy too. So, you should get the job done immediately, or else you risk further damage to your 4.6 engine.

4. Unexpected Misfiring Of The Engine

We have finally arrived at the last and the most dangerous problem of them all, the sudden misfiring of the engine. Various Ford 4.6 engine owners have reported this problem, and I shall be telling you why it happens.

If the 4.6 engine suddenly starts to misfire, then the chances are that there is something faulty in it. The most probable thing is that the spark plugs or the ignition coils have failed.

This is an issue found on the Triton V8, so Ford had a serious issue back then. It has been confirmed that many 4.6L V8 owners had spark plug issues.

Faulty Spark Plug

So, how does a spark plug fail? Users reported that the spark plugs in their vehicles broke into two while driving. This is a very serious issue. It poses a safety hazard for the driver and the vehicles around him but removing a broken spark plug is a difficult and expensive job.

So, how can you notice that a spark plug on your vehicle has gone bad? Well, there are many symptoms, including misfires. In the Ford 4.6 engine, the misfire issue is the most common one. You may also notice rough idling and very poor performance once the spark plug breaks.

So, the best way to avoid this issue is to replace the spark plugs after every set interval. For example, the advised distance range for a spark plug is 100000 miles.

After that, you should get a replacement. The plugs may get stuck while removing too, which may cause them to break into two pieces. But that is a very rare scenario.

Faulty Ignition Coil

The ignition coil may break too. It is responsible for minimizing emissions. The coil may get disconnected, which does not allow the engine to start up. If it still doesn’t, then you should get a replacement.

Repair

A spark plug replacement is very expensive because of the level of difficulty of the removal process. The ignition coil is easy to replace, and it will not cost you too much either. Either way, if you don’t maintain your 4.6 engine properly, you are bound to experience this.

If the engine has suddenly started to misfire, then there are three reasons for this to happen:

  • The spark plug has failed, popped or has been broken
  • The ignition coil has become faulty
  • Long intervals between maintenance

What Is The Ford 4.6 Engine?

The Ford 4.6L is the first family member of the modular engine series produced by Ford. It was very popular in its time and is still able to output very decent performance.

The first vehicle to feature it was the 1991 Lincoln Town Car. It was also then featured as the base engine on the Mustang GT. It had three-cylinder heads throughout its duration.

From 1990 to 2014, the company used a 2-valve design. But, during 2005 and 2010, they also introduced a 3-valve design. There was also a 4-valve one, and it was an excellent performer.

The 4.6 engine could snatch up a spot on Ward’s 10 Best Engines list in 1996 and 1997. The 3-valve model was on the list from 2005 to 2008. Buyers were in love with its performance. So, it was a worthy contender.

Is The Ford 4.6 Engine Reliable?

The 4.6 engine was almost on the top of the list when it came to reliability. Although Ford did cut some corners to reduce the cost, such as using plastic for the intake manifold, the company did make sure that the compromise would not affect the engine in any meaningful way.

There is a reason the company kept manufacturing it for well over two decades, and buyers kept buying vehicles with this bad boy under the hood.

I agree that there are some problems, like the ones I listed above, but you are bound to find similar problems in engines of all shapes and sizes. Plus, most issues are easily fixable, so you don’t have to worry about that too much.

The reliability can be improved even further if the engine is maintained throughout its usage. Buyers have crossed the 300000 mile limit with this engine, with minor issues.

What Cars Use The Ford 4.6 Engine?

The Ford 4.6 was a beastly engine. It was featured in multiple vehicles, ranging from vans to the company’s premium Mustang GT series. The first-ever vehicles to feature this engine, in 1991, were the Ford Crown Victoria and the Lincoln Town Car.

After that, the manufacturer started using it in many different series. It was used in the Ford E-Series, the Ford Expedition, and the Ford Explorer. The manufacturer even included it under the hood of the Ford Explorer Sport Trac. It was featured in the Ford F-150, one of the USA’s highest-selling Ford trucks.

Other vehicles shipped with this engine were the Ford Thunderbird, the Lincoln Aviator, the Lincoln Continental, and the Mark VIII.

The Mercury Cougar, Grand Marquis, and the Marauder were also some vehicles that used this engine. So, within two decades, there were plenty of vehicles that featured this engine under the hood.

Ford 4.6 Engine Specs

Cylinder block composition Aluminum, Cast iron
Cylinder head composition Aluminum
Fuel Gasoline
Fuel injection type Sequential multi-port fuel injection
Configuration V
No. of cylinders 8
Valves (per cylinder) 2/3/4
Valvetrain layout SOHC/DOHC
Bore 90.2 mm or 3.55 cubic inches
Stroke 90.2 mm or 3.55 cubic inches
Displacement 4.6L
Internal combustion engine (type) Four-stroke, Naturally aspirated
Compression ratio 9.0:1 – SOHC 2-Valve Engine / 9.8:1 – SOHC 3-Valve Engine
Power 235HP at 4250 rpm– 2-Valve SOHC / 310HP at 5000 rpm – 3-Valve SOHC
Torque 330 lb.-ft @3000 rpm – 2-Valve SOHC / 365 lb.-ft @ 3500 rpm – 3-Valve SOHC
Weight of engine oil SAE 5W-20
The capacity of engine oil 6 quarts w / filter
Firing order 1-3-7-2-6-5-4-8
Oil change interval 5000 miles (10000km) or six months

The Benefits Of Choosing The Ford 4.6 Engine

It is understandable if you still are unsure if the Ford 4.6 engine is worthy. Well, these few benefits will change your mind.

  • It has a completely modular design
  • V8 engine for excellent performance
  • Offered in 2, 3, and even four-valve variants
  • Cast covers are made from aluminum and not plastic for added durability
  • Features long intake runners that improve torque

FAQ

It looks like some of you still are not satisfied with the engine. This FAQ is directed towards some of those people that that still have some confusion.

Is The 4.6 Ford Motor good?

It looks like you skimmed through the entire article and jumped directly to this buying guide. I reassure all of you buyers that the 4.6 engine is not good but great. With very few reliability issues, it is one of the best engines that Ford ever made.

How Many Miles Is A 4.6 Ford Engine Good For?

This all depends on how you maintain the engine. If you perform periodic maintenance tasks to keep the 4.6 engine in pristine condition, then you can expect it to last well over the 200000-mile mark. This is more than enough for most people. So, you can expect the engine to hold on for a very long time.

What Years Ford 4.6s Had The Spark Plug Problem?

There were spark plug issues in almost all models of the 4.6L V8, but it was commonly found in the 2004 to 2008 models of the engine. If you are planning to buy a vehicle with an engine from this manufacturing date, I would recommend getting the spark plugs checked.

Is The 4.6 Or The 5.4 Engine Better?

Honestly, this is not a fair comparison. The 5.4 Triton easily takes the lead when compared to the 4.6L engine. But both are excellent performers, and the torque on them is more than sufficient for most people. But the 5.4 is a clear winner if you decide to compare both of these beasts.

Conclusion

It is difficult to identify all Ford 4.6 engine problems. But this article details how to identify the most common ones and how they should be addressed. I have researched thoroughly before starting with the article, so you can rest assured that every piece of information is accurate.

If you are planning to buy the 4.6L V8, you should do so, by all means. If you did buy it, I must congratulate you, as you have a monster of an engine on your hands. I hope that this article enlightened you about the common issues with the Ford 4.6 engine.