If you have a lumpy idle with your DB9 (like mine was as detailed in this blog post) or are just doing a scheduled service that requires changing the plugs, it will be helpful to know all the parts you’ll need. Of course, you’re sitting there going ‘Duh – I need spark plugs to change spark plugs you idiot’. Yes, that’s true, but you also need a small assortment of other bits and bobs to put it all back together Properly.
The list isn’t that long, but I wanted to share the part numbers, sources, prices and other details with you to make your effort easier. I’ve included a lot of photos too, and at the very bottom of this post (below the video) I have included a photo gallery of each part from various angles in case you are trying to compare something to the official dealer part (like sourcing from a Ford dealer).
Several of the parts I discovered are actually Ford items. Blasphemy you say!? We’ll, I’m over the surprise of this now, the DB9 includes many Ford, Mazda and Volvo bits. Sourcing the bits from suppliers other than an Aston Dealer might be possible, and I will note this if I can find them.
PCV Valves Too…
As I embarked on my Coil Pack service, I decided I would also service my Positive Crankcase Ventilation (PCV) valves since they are buried in the same area. Why? I have covered this topic separately in another series of articles (starting with this one – please check it out) but the short version is that I spotted the all too common engine oil build up in my air intake plenums, a sign that the PCV valves have failed and are letting oil through. The parts for this will are included in this blog post, including a cautionary tale to save yourself some major hassles and expense.
Below are all the items I purchased. I got them all from HWM Limited in England and shipped to me in the USA. I was literally stunned when the parts arrived in California just 3 days after I ordered them. Wow, faster than my regional dealer and vastly cheaper! Well done HWM. Here is a copy of the invoice in case you are interested in the details (I ordered some other parts for future projects on the same invoice so pay no attention to those). If you are interested in ordering from them, please reach out to Rob Sims (and let him know you learned about the parts from this blog).
There are two versions of the coil packs, the original ‘2-pin’ model (describing the number of electrical connectors it has), or a later ‘3-pin’ model. I don’t know when the change over occurred (sometime in MY 2006 I’ve read in the forums), so you’ll need to sus this out a bit with your dealer before you order the parts. My car was the 2-pin version shown here.
If you are replacing all of them (which I advocate for in my other post describing the lumpy idle and its cause) you’ll need a quantity of 12 of them, one for each cylinder.
Qty 12 – Aston Martin P/N 4G4E-12A366-AA (Ignition Coil and Boot Assembly – 2 pin for early cars)
You can find them online for $66 USD each here, and I paid about £39 ($51 USD) each from HWM (even better).
Technically there is no need to change the spark plugs if you are dealing with a failing coil pack, but its good insurance to do so. Maybe you are just doing your plug change as part of your 70,000 mile service (ya, right, a DB9 with 70K on it, ha-ha-ha)!
When you open your dealer supplied official Aston Martin spark plugs, out will come an NGK brand model PTR6E-13 spark plug. I’ve searched some to try and find this exact plug directly from an NGK online source, but no luck so far. I suspect it’s a bespoke model strictly for Aston Martin (let me know if you find a source for the exact model).
They are sold individually (P/N 07-85126), or in slightly cheaper 4 packs (which are more common).
Qty 3 – Aston Martin P/N 07-85126-PK (Spark Plug Vanquish/DB9 Box of 4)
You can find the box of four online for $94 USD, and I paid about £55 ($73 USD) each from HWM.
[Updated June 2020] I think you should consider a different plug if you run an early model DB9 like me. Here’s why. I’ve been working with Velocity AP on applying a new ECU tune to the car to get a few more horsepower (a simple software ugprade you can apply). The original DB9’s made about 450bhp, then there was a 470 bhp version, and then the DBS makes about 500bhp. My goal is to get up towards the same power as a DBS.
Chris Edgett at Velocity AP (a.k.a. Irish07 on the forums) recommended that I consider fitting later model DB9 spark plugs (MY 08-12) as they run ‘cooler’ and this will allow the ECU to run more advance on the ignition (and make more power). This isn’t some aftermarket snake oil, its essentially just fitting the same spark plug Aston evolved to on their own. Now we can take advantage of it in the earlier cars too.
Tech Background – “When a spark plug is referred to as a ‘cold plug’, it is one that transfers heat rapidly from the firing tip into the engine head, keeping the firing tip cooler.” This in turn keeps the engine from pre-detonating (pinging or misfiring) when it’s under load. The original plug that came with my DB9 was NGK p/n PTR6E-13. The ‘6’ in that p/n indicates the heat range of the plug, The later model year cars have NGK plugs with a ‘7’ heat range, one step ‘cooler’. Learn more about Spark Plug heat ranges here on NGK’s website.
The plug is Aston Martin p/n 5R13-12405-BA. Best purchased in a box set of 4 and you’ll need qty 3 of these to get 12 plugs. The box set of four is Aston Martin P/N 5R13-12405-BA-PK. You can find these online for about $108 USD each. These are the plugs I will be giving a try soon.
[An Alternative Plug] – Contributor to this Blog Mike (Aston 2209) did a bunch of great research to work out if NGK could just sell us an equivalent plug without the bespoke Aston Martin markup. He contacted NGK UK and they pointed him at their Laser Iridium Plug NGK p/n ITR6F-13 (4477). This is the same ‘heat range’ as the original plug (NGK range 6). They have a tapered fit shoulder for sealing into the cylinder head (same as the OEM). The good news is that these are notably less money and can be had for under $11 USD each (compared to nearly $25 of the OEM). You can buy them as a 4 pack for about $42 USD on Amazon.com. Twelve of these will cost you under $130 USD, a considerable savings over OEM. Note: I’m not sure this is a corner I want to cut since the plugs are very difficult to reach. Keep in mind that I have not run this plug first hand, but Mike has with good success.
Intake Manifold Gasket(s)
You may need 1 or 2 of these, depending if you are removing just one intake or both. If you remove an intake manifold, REPLACE the gasket every time. Don’t reuse and risk a leak. It will ‘position’ slightly differently each time its installed (even with the aligners), so it may not work right the second time around.
They are available individually (P/N 1R12-08-10077) or slightly cheaper in a more common 2 pack set (which is what I bought).
Quantity 1 – Aston Martin P/N 1R12-08-10077-PK (Gasket – Inlet Manifold/Head 2 Pack)
The gaskets aren’t cheap. You can find it online for $238 USD, and I paid about £138 ($183 USD) for the set from HWM.
Fuel Injector O-Ring – Upper and Lower
Part of removing the Intake Manifolds requires removing the high pressure fuel rails and fuel injectors. Each fuel injector has two o-rings, and upper and a lower. The O-rings create a pressure seal for the fuel, and its cheap insurance to replace the ones that have been baking in the bowels of the engine for 10 years with a new set of supple ones.
The upper o-rings that engage the fuel rail are Blue. The lower o-rings that engage the intake manifold are Green. Different sizes, not interchangable. These are Ford parts, and made in the USA. See my extra photo gallery at the bottom of the post if you want to see all the info on the boxes to try and search them out at a Ford dealer.
They are sold individually or in packs of 8 (since the part is shared with the Vantage or other Ford and Jaguar V8’s I guess).
Quantity 12 – Aston Martin P/N 6G43-08-10474 (Seal – Fuel Injector to Manifold – Blue)
You can find the 8 pack online for about $27 USD (you’ll need 2 packs to get enough), but I bought 12 single O-rings for £2.04 ($2.70 USD) each from HWM (which is silly for an o-ring when you think about it).
Quantity 12 – Aston Martin P/N 6G43-08-11260 (Fuel Injector O-Ring – Green)
I bought 12 single O-rings for £2.16 ($2.86 USD) each from HWM.
Here is a short video where you can see more detail about the parts.
Below are photo galleries of each part from all sort of angles (in high resolution), maybe one of the views will answer some question you have.