It's the first time I've ever replaced sparkplugs (myself) on my 95 Thunderbird LX 4.6L V8 and I got a surprise when I pulled out the first sparkplug. It's a Motorcraft AWSF 44PP. And it does look a little different than the SP-493 platinum sparkplugs that Advance Auto sold me. After doing some research I found, as far as I can tell, the Motorcraft AWSF 44PP sparkplug has only ever been specified in regards to the Thunderbird for the 3.8L 232 Cu. In. and the 5.0L 302 Cu. In. engines. I bought the car new and cannot recall ever having the sparkplugs replaced, a big no-no I know, but the car still runs great. So either these are the original sparkplugs which I'm having a hard time believing, or somewhere along the line I had a shop do a tuneup and they put the wrong sparkplugs in my engine. That's much more likely. I went back to Advance Auto Parts and the guy couldn't give me a definitive answer, but said he wouldn't use the SP-493s because he was unable to find on his computer that they were ever a replacement for the AWSF 44PP. Hmm... I think there's a flaw in that logic somewhere. I then went to Riley's down the street and they couldn't tell me anything either. I'm planning to go to the local Ford Dealership and talk to the parts dept. before I go ahead and put the SP-493 sparkplugs in my 4.6L V8. Based on what I can tell the AWSF 44PP would stick into the combustion chamber an eighth of an inch more than the SP-493 would, which would mean that I don't have to worry about the piston smashing into it. The guy at Advance Auto Parts said that the SP-493 would actually stick further into the combustion chamber because it has more threads than the AWSF 44PP, but I think the more threads idea doesn't really work. Since the distance of both plugs is the same from where they seat externally to their tops, all I have to do is make sure that the top of the SP-493 sits no lower in the hole than the AWSF 44PP when they are both snug in the engine. If anybody knows anything more about this issue I'd appreciate any info you could provide as I am not an expert by any means. Thanks. ~Tbird46
Well it's another day, and based on additional research I have concluded that whoever replaced the sparkplugs previously either didn't know what he was doing, or decided that because he didn't have the right sparkplugs he'd reduce his inventory of AWSF 44PPs. The AWSF 44PP are not the right sparkplugs for a Ford 4.6L V8 engine. Sheesh, some people. The only person who could have done that was either someone at a Ford Service Dept. or an independent shop. The SP-493s are the ones they should have used. This was confirmed not only by sparkplug charts found on eBay, but also from information found at "parts.ford.com." Live and learn, my grandpappy always said. Well, at least this time, since I'm doing it, I'll know that I'll have the right sparkplugs running in my car. Thanks to all those who bothered to read my post and for your replies. Ta ta....
Okay boys and girls, just thought I'd do a post market wrap up on what they told me at our local Ford dealership today. There were two young guys, probably in their late 20s to early 30s manning the parts counter. Me? I'm an old fart in my mid-60s. Fortunately there was only one customer in front of me, so it didn't take long for them to get to me. I told them that I was changing the sparkplugs out on a 95 Thunderbird with a 4.6L engine and I showed them the Motorcraft AWSF 44PP that I pulled out of #5 and I also showed them a brand new Motorcraft SP-493 still in its box. I said that based on the research I had done so far, I had concluded that the AWSF 44PPs should never have been put in the old Bird, and that they were actually for the Ford 3.8L and the 5.0L. One of them immediately got on his terminal while the other guy watched over his shoulder and within a minute or less, they confirmed that my assessment was right on target. The correct Motorcraft platinum sparkplugs for the 4.6L Ford engine is the SP-493s.
For anybody wanting some info on changing out sparkplugs on a 4.6L, here is a good Youtube video that is actually quite entertaining. It shows the old boy replacing the sparkplugs on his 2005 Crown Victoria Police Interceptor 4-Door Sedan that has the 4.6L V8. And yes he's putting in the SP-493 platinums. It's definitely good for a few laughs, but I learned quite a bit from it at the same time. Well, that's all folks. Time for me to get my butt in gear and get the rest of those AWSF 44PPs out of my good old '95 T-Bird LX. 4.6L V8 - Hasta la vista! -