Q: I'm having a very rough idle and the cheek engine light came on in my 98 expedition 5.4L engine. Your guess at the cause?

asked by on

I'm in a 1998 5.4L engine ford expedition. Truck starts but odors rough with check engine light on and off, and also feels as if it's going to shut off during driving.

My car has 240 miles.
My car has a manual transmission.

Hi there:

Although guessing on what could be wrong isn’t an ASE best practice method of fixing a mechanical problem, there are a few items that could be causing the rough idle. First, anytime a check engine light comes on, it’s because a mechanical or electrical component has triggered an error code, indicating that a problem exists. By downloading those error codes first, a professional mechanic is able to trace the issues to one or a few individual parts. In most cases, the rough idle is caused by dirty or clogged fuel injectors, the throttle body being dirty or damaged, the idle control valve being damaged, or the EGR valve needing to be replaced or simply cleaned. To know for sure, contact one of our mobile mechanics to complete a car idle is rough inspection first. This way they can download those error codes and pinpoint the source of your engine issues and recommend the right repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. I'm having a very rough idle and the cheek engine light came on in my 98 expedition 5.4L engine. Your guess at the cause?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My car will not accelerate in speed and there is a knocking noise

Hi there. Usually when you're driving and you notice a loud popping sound, followed by deceleration and troubles maintaining a higher speed, the issue exists within the transmission. However, there are multiple engine components ranging from ignition systems to fuel...

Q: Ticking noise coming from the driver's side of the engine

Often, that would be lifters making a noise. So, the first thing you'd want to do is get some good engine oil flush and have the engine flushed out, and then change the oil and filter. A lot of times,...

Q: Clanking while pressing gas, making a turn and accelerating

The problem sounds like your transmission broke a forward over-running clutch inside the transmission. I would recommend having a mechanic inspect to determine if the noise is from the transmission or the engine, since both the engine or transmission can...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...