Mercuryman2003

[Mercuryman2003]

Hello,

I have a Mercury Grand Marquis 2003. I wanted to save some money and install three ignition coils and spark plugs. I have never installed ignition coils before. Do you recommend the dealer perform the work. Their charge is $600.

Thanks

[way2old]

You can install them yourself. It is not an a hard job. All you have to do is remove the connector, remove the little bolt,(7mm I think) and pull coil out of the plug well. When you install them, just be sure they are seated down fully and install the little bolt and install wiring connector. Just be sure you do not drop the plug in the plug well as you could damage it. I use a section of 3/8 vacuum hose to start the plug into the threads. Good luck.

[Mercuryman2003]

Did you have to gap each plug or could you get them already gapped? The dealer diagnosed three coils and three plugs were bad. Should l replace all eight plugs and/or coils? If I do not replace all eight, what device do I use to test for bad coils to be replaced in the future?

Thanks

[way2old]

At the price of the coils, most people will just replace the coils that are bad. Here is a site that has one fairly cheap. The Motorcraft number is DG-508
click here

[Mercuryman2003]

Great information
Thanks for all your help.

[Mercuryman2003]

Where are the ignition coils located?

[way2old]

They are located under the chrome fuel rail. The following link has a generic picture of the location. Good luck. Click here.

[Mercuryman2003]

Great, thanks again