When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have an 05 SD with a 5.4, just turned 99,000 miles almost all highway driving. Bought a new set of plugs I plan to install in the next week or so..... while I have them out should I replace the coils also???
Thanks, for the reply. No problem with coils, I write my miles down every time I drive the truck then average my mileage for the month... June was 13.8 for the month which is about normal for the truck. I just thought there might be that magic number when the coils start dying.
I'd save the plugs until you need to replace the coils and do them at the same time. My 195k mile 97 5.4 still has the original plugs, coils, and wires and runs great.
I agree with ReAX. The COP's will fail at some point and it really depends on how much "reliability" do you want and/or need. It sounds like you are doing a lot of highway driving. If you can afford it, it's probably a wise decision to install new COP's as well.
I wish my F350 with 5.4L engine used the same ignition system design as my 1998 Mustang GT with 4.6L engine. I can purchase high quality plug wires for $60.00... even with 130K miles on the engine, I have yet to have an electrical failure.
Ford needs to learn that more advanced is not always better!
That's some life. My plugs had excessive gap at 68k, I think they averaged 0.072" and created a noticeable miss.
The older coils/engines had some issues, but they weren't very common. If your OE coils are still running fine, they might last another 100k. Heat cycling could speed deterioration of the innards, but I think it's actual age is harder on them miles, and worse would be the impedance of the plugs.
On my 1998 Mustang GT, I did replace the plugs (Motorcraft) and plug wires (Ford Racing 9mm) at 75K miles. It's time to do it again. I may replace the coils this time...
Thanks for the replies, there's a set of Accel COPS on Ebay for about $300.00 plus shipping......sure beats $65 ea at NAPA, anyone had any experence with Accel COPS??
Accel doesn't have the greatest reputation with ignition coils. When I was looking to replace mine, the mustang people hated them (and I had trouble with the LT1 and TFI coils in the past.) At that time GMS had launched a line of coils that they were hopeful over. I haven't been over there enough to check, but I think they were having troubles too. There is an advertiser here, who might have a deal, I want to call them pertronixs, but I don't think that is them.
I agree with ReAX ... there doesn't seem to be a time frame when these coils go. I've replaced 3 over my 120000 miles, but the rest are giving me good date. If you were changing the plugs, for sure at least look very carefully at the coil boots, if not change them ... and properly seal them up.
There was a guy on ebay selling what he said were new motorcraft cop's at a real cheap price .... the earlier part number. Someone here bought a bunch of them.... he never got back to me on their quality, etc.
Furian, read the SOS thread, maybe another option....... couple NICE trucks, maybe the picture angle but your 05 looks like it sets MUCH higher .
That's no illusion... Both trucks have stock suspensions, wheels, and tires. Ford really increased the size and stance of their heavy duty truck when they introduced the "Super Duty."
For what ever reason I"d never really noticed THAT much of a difference between the two before....... my eleven year old was standing behind me when I said something about the 05 looked HUGE...... only thing I heard behnd me was DUH!!!