2005 DB9 ignition coil life span
 

I'm replacing the spark plugs since I noticed a little roughness in the idle. I've seen a few comments about coil failure and am considering replacing them. The car only has 25000 miles on it. Not sure if I should spend the extra money on them or not. Has anyone had a failure and how many miles on them?

With the rough idle, age of the car (if coils are the original) and your commitment to the labor of replacing the plugs..... making the coils accessible - Yes, I would replace coils AND plugs. Have diagnostics shown failure of either? A reputable Aston Tech told me that it's somewhat common that DB9 coils need replaced in the 30,000mi range. Usually the coils need replaced so while apart the plugs can be replace with little added labor cost. Your looking at the reverse situation. Your rough idle might not be due to either. I'm not sure I'd do the job without a diagnostic summary of the engine performance first. The rough idle could be something else. As a fellow owner I'd be interested in the outcome if you decide to change them.

Early model coils were a very common problem.......If yours are original, you're overdue

We are roughly 2/3 of the way through developing a coil pack for these cars at 1/3-1/2 the price of the original, and with the design flaw that causes short life to be rectified. More powerful spark also.

Hopefully will launch with a group buy.

V8 and V12? Or just V12?

I went ahead and ordered the coils today. I bought the car a year ago with 12000 miles on it and put 12000 on it since. Always seemed slightly rough but in November it had a few misfires in gear hot. Secondary ignition seemed to be the most likely cause so I pulled the plugs and didn't see anything obvious.

What?!?! You went through all the trouble of getting at the plugs and didn't change the coils at the same time?!

@XJRS if there was no history of coil failures I would not.

Changed mines at 25 000

But there is a very well documented history of just that.

Any one knows any cross reference pet number for ignition coils for DB9? If it is journey or Volvo?

Don't know of any cross reference for the 3 pin coils....2006+

It might just be fouled plugs causing your problem, when it is apart make the decision to replace coils depending on spark condition/color etc.

Or give it an Italian tune up

During my research on finding a replacement coil for my DB9, I came across a thread on a Ford forum, where someone noted that the ford DG-517 coul had been superceded by the DG-528 coil. When I talked to an AM tech when I had the seat heater recall done, he mentioned that the DB9 coils had been updated. Funny thing is, tech told they had changed about the exact same time as the Ford thread said the change to DG-528 happened.

After researching some more, the 2 pin DG-528 is the AM coil, just with a different boot. I took a coil CARAIBAM provided (thanks again) and a Delphi DG-528 equivilent to a friends shop and had himn test both, the OHM'd the same and put out almost the same voltage (the one CARAIBAM provided was used). I am planning to replace mine once I get my car back from the body shop with the Delphi's.

Nice work I will look up
Do you have any photos?