Miss fire Cylinder 7

[LSV803]

I recently had 2004 Lincoln ls engine v8 put into my 2003 Lincoln ls, After it was finished there was a sputter, the mechanic thought it might of been bad gas or cause the engine sat for awhile. Well the engine light would come off an on when really stepping into the pedal.

finally got the engine light to stay on an its a miss fire on cylinder 7, my question is what steps i should take to diagnose whether this is the spark plugs or coil packs or even if its something else. any price est? an is this a job i could take on myself? Thanks for help, i really appreciate it!

 

[myfirstlincoln]

Honestly, replace all coil and plugs.

I assume the 2004 engine has quite a few miles on it and I assume you aren't completely sure of its history. I personally would have replaced the coils and plugs before I even put it in the car.
Replacing coils and plugs is pretty easy and can be done without any crazy tools. Oh, and check the wells for oil...could need vcg replaced

 

[LSV803]

got any estimate on how much this might cost?

an the engine had around 74,000 miles on it. but correct i don't know the history behind it.

 

[myfirstlincoln]

I would assume that the coils have never been replaced, but I could be completely wrong. If they haven't been replaced, it may not be a bad idea to replace them all at once. It seems that once one goes bad, the rest follow shortly.

If you do it yourself, it will take a couple hours. You can probably find 8 Motorcraft spark plugs for about $60 on ebay or something, but coils are a different beast. You can find coils fairly cheap but their reliability is a question. For example, you can get a set on ebay
http://www.ebay.com/itm/SET-OF-8-IG...:Lincoln|Model:LS&hash=item27d1ed24aa&vxp=mtr

However, I don't have much faith in those coils being quality. A bunch of us on this site went with Visteon coils but they're basically impossible to find at this point. Your best bet is Motorcraft coils but then (if you replace all 8 at once) you're looking at it being much more expensive. If you can find a set of 8 Motorcraft coils, you'll be lucky to get them for around $450.

However, if the wells are filled with oil, then that's a whole diff story.

Depending on what you're trying to do with the car, I would replace the plug and coil on cylinder 7 and go from there. After that, you could possibly drive the car for a year+ with no problems or you could possible drive the car for a day and another coil goes bad...

 

[LSV803]

I bought one year parts & labor warranty service for the engine, so im going to get a hold of the mechanic who put it in an the place i bought it from an get it worked out. i agree, the plugs an coils should have definitely been checked before the engine was ever put in.

if so happens they don't cover it, or the mechanic screws me over, ill go about replacing it myself.

I appreciate all the help you guys provide here, been life savers. thanks again!