Hi all:

I'll be replacing the coil packs and plugs on my 03 4.6L Expedition. Any recommendations for either part? I'd like to use quality parts, but not necessarily break the bank.

Thanks in advance.

 

Motorcraft plugs. Unless you are looking for higher performance. Again unless you are looking for higher performance I wouldnt change the packs unless there is something wrong with them, those get rather expensive. Do you have a 2 or 3 valve motor?

 

Hi xSgt..

Thanks for the response. Coils are ready to be changed...so they have to go. And I have the 2 valve Romeo.

 

What makes you think the coils are ready to go bad? They either work or don't, no in between.

If you don't want to "break the bank", just change the plugs with good plugs as noted above.

No reason to spend a dime on CP's until necessary. Even though mines a 5.4, I've changed two individual units in 317,000 miles.

 

CPs are $100 easy per cylinder. Motorcraft iridium are quality plugs.

 

Rock Auto has Motorcraft coils for $42 per, a dealer will hit you for 75-90 for the same part. They have economy versions also. You can find them on eBay for as low as $8 each.

 

Thanks for all the responses. I'm going to rethink changing the cops. I'm getting a missfire (haven't pulled a code yet, was planning to have the code checked at the store) and with 134K on the truck, I just figured it was time for new cops.

 

Probably time for one. See what the code says and change that one.

 

Code came up p0300. That code has a list as long as your arm on the root cause. So...before I start dropping a lot of coin on new COP..plugs etc., lets just start out with cleaning the MAF sensor. From there will be checking vacuum hoses, egr valve and so on. Hopefully it's something simple.

The missfire code (p174) said it was random cylinders, not one specific cylinder.

Anyway, I'll post a report later on whether or not the MAF cleaning helps.

Again, thank you all for your responses.

Glenn

 

Normally P0174 is accompanied with P0171 which is a Bank 1& 2 lean...not a misfire

 

Was it a P300 or a P174 code that you got?

 

I had a misfire on mine a couple years ago and my autozone code reader was pointing me towards a bank one lean issue. Turned out to be a cracked vacuum hose. I was convinced it was a bad COP so I bought one as a spare and it still sits in my tool box unopened.

 

Hi again...

Well I had both the 0300 and 0174 codes. 174 is the lean code correct? I've started with cleaning the MAF sensor..that helped somewhat but still not right.

So, before I start messing with COP and plugs, I thought I'd start with vacuum lines etc. The inexpensive stuff, plus with the age of the truck, the vacuum lines probably are starting to dry out.

The truck has been parked now..I really don't want to drive it with the light on, so sunday I'll start with the vacuum lines/PCV valve and related grommet.

Any other suggestions would be appreciated.

Thanks again.

 

The P0300 code means you're getting misfires on multiple cylinders. These misfires in turn cause the P0174 code. So your first step is to find and fix the misfires.

 

Hi Alloro...I was told that if there was a bad vacuum, PCV valve, etc that the PCM would lean out the engine, causing the misfires. This is why I first started with the vacuum lines before I jumped into either the COPS or plugs etc.

I've changed the PCV valve..the old one was pretty gunked up and the truck runs better, but it isn't running as it should.

One step at a time, I guess.

Thank you for your response, I do appreciate your time.

Edit: I did clean the MAF sensor..that too helped a bit.