2005 running rough

[chiefwest]

My 2005 50th Anniversary Edition was been running rough and misfiring for a while now. I’ve had new spark plugs put in, the coils checked. One garage said they repaired a crack in the driver’s side valve cover, that didn’t fix the problem. The check engine light has not come on. I would appreciate any suggestions. Thank you.

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[biddle]

First, you need an OBDII reader to read any pending codes, some of the advanced readers may also have suggestions.

Next, you should have noticed when you were creating this thread, there are a number of posts about this. Check out similar threads above and below and also use the search page for rough idle, running rough, etc. Could be all sorts of things causing the issue related to the throttle body area as noted in this post- https://forums.fordthunderbirdforum.com/threads/2005-rough-idle-reprogram-question.8580/post-54598


Also, how old are the COPS? Most people have to replace those, spark plugs and valve cover gaskets. The fact they said they "checked" the COPS makes me wonder about this.


Also, I removed "50th Anniversary Edition" from your subject. This isn't really relevant to your issue at hand.

 

[Anewaltj]

My 2005 50th Anniversary Edition was been running rough and misfiring for a while now. I’ve had new spark plugs put in, the coils checked. One garage said they repaired a crack in the driver’s side valve cover, that didn’t fix the problem. The check engine light has not come on. I would appreciate any suggestions. Thank you.

Happy New Year!
I have a 50th anniversary which I've had for 4-1/2 years, 47k miles.
It ran fine... mid last year I bought new plugs and coils and boy what a difference. If you search the site, there is a listing for the latest coils found on Amazon. I had mine put in for about 3 hrs. of labor. definitely worth it. I also replaced the struts with KYB's and they made a big difference in the ride and handeling.
As you read this blog, you will see that most all engine misses are cured by new coils.
These cars are getting to the age where they need a little maintenance but, they are worth the investment if you enjoy driving them.
Jim from Asheville

 

[JW in Dixie]

Buy a OBDII code reader! Best $15-30 you will ever spend. Don't leave home without one.

 

[Frankie the Fink]

Yes, buy a good ODBC reader (I prefer the Blue Driver on Amazon but its pricey, with outstanding features tho).
And might not hurt to run a bottle of Techron (or two) fuel treatment through the gas tank...

 

[chiefwest]

First, you need an OBDII reader to read any pending codes, some of the advanced readers may also have suggestions.

Next, you should have noticed when you were creating this thread, there are a number of posts about this. Check out similar threads above and below and also use the search page for rough idle, running rough, etc. Could be all sorts of things causing the issue related to the throttle body area as noted in this post- https://forums.fordthunderbirdforum.com/threads/2005-rough-idle-reprogram-question.8580/post-54598


Also, how old are the COPS? Most people have to replace those, spark plugs and valve cover gaskets. The fact they said they "checked" the COPS makes me wonder about this.


Also, I removed "50th Anniversary Edition" from your subject. This isn't really relevant to your issue at hand.

The COPS were replaced 6 years ago when I bought the car.

 

[biddle]

The COPS were replaced 6 years ago when I bought the car.

Have they been inspected recently? Did they replace the valve cover gasket at that time? If not, one or more of the COPS could have failed again. I see a lot of people with repeat COPS issues because the valve cover gasket isn't replaced or sealed properly.

 

[biddle]

@chiefwest what was the problem?

 

[chiefwest]

It was difficult to find a mechanic that was familiar with T-Birds. One said I needed a front electronic module. Mine was sent to G7 in New York for repair. Unfortunately, that did not fix the problem. Another mechanic said I needed a part that was he could not find (I don’t recall what it was). Lastly I found a great mechanic who found a misfire on cylinder 3, changed the COPS and plugs, and now runs perfectly.

 

[Frankie the Fink]

It was difficult to find a mechanic that was familiar with T-Birds. One said I needed a front electronic module. Mine was sent to G7 in New York for repair. Unfortunately, that did not fix the problem. Another mechanic said I needed a part that was he could not find (I don’t recall what it was). Lastly I found a great mechanic who found a misfire on cylinder 3, changed the COPS and plugs, and now runs perfectly.

For ALL of my modern and classic cars I keep a sinmple bulletized "log" file by date of reparis, upgrades, conversions in MS-Word - it saves searching through piles of old faded receipts to know what was done, where and by whom. It can save you a lot of detective work when some mechanic or shop says you need something and maybe you don't. It doesn't have to be complicated:

 

[rcwitt66]

My 2005 50th Anniversary Edition was been running rough and misfiring for a while now. I’ve had new spark plugs put in, the coils checked. One garage said they repaired a crack in the driver’s side valve cover, that didn’t fix the problem. The check engine light has not come on. I would appreciate any suggestions. Thank you.

I have been fighting a similar issue for a couple of days now. Before you go throw out money on parts (I replaced the O2 sensors, the EGR valve, and all 8 plugs, all 8 coils), check your vaccuum lines. Unmetered air can cause both of the problems you are having.

Mine also had a very dry, brittle corrogated line from the intake (near the EGR) to the passenger side valve cover. It literally broke into pieces when I tried to move it. With the engine running, listen carefully for any hissing sounds - virtually all vac leaks will hiss.

I heard the leak easily over the sound of the engine once I started looking for it. The replacement line for mine was around $45. I'm not going to say the other few hundren I spent on parts wasn't the problem, because my wife would never let me live it down. LOL. But the more I look at my situation (it is an ongoing saga), the more I am thinking it was the vac leak all along.