I have a 1999 F250 Super Duty with a 7.3L Diesel, I would like to change my glow plugs (145000 miles and have already replaced the relay). How hard are they to change and where can I find do-it yourself instruction

 

I don't have any links to instructions, but they are basically like very slender spark plugs mounted right next to the injectors. You must remove the valve covers to access. It's easier than you think. Tip on removing the stud that holds the dipstick tube: There is a six sided shoulder underneath the nut that holds the tab. Lot's of times the whole stud will come loose instead of just the nut. If you don't loosen that nut, the whole dipstick tube turns into a pretzel during removal or you have to cut the tab. Then there is no securing the tube after that. What I do is get a wrench in the size that you need and grind the side of the open end until it's thin enough to fit under the dipstick tube holder and prevent the stud from turning. Then remove the upper nut.The hardest part is overcoming gravity as you are leaning WAY over your engine and changing out the rear plugs.
I recommend getting new valve cover gaskets and wiring harness's if you havn't already. My '99 wiring was routed in such a way as to have the glow plug wire rest against the push rod and wear through right down to the conductor. Plus the inside plug tends to work it's way loose and fall off on the inside.
Be very careful when removing the old ones as the tips have a tendancy to stick in thier holes and stay behind when you remove the glow plug. Lot's of Free-all and working back and forth will eventually get it out, but I have heard that some of them flat won't and the head has to come off to complete the job.
Here' my experience on this matter:
https://www.ford-trucks.com/forums/s...d.php?t=278697

 

Thanks for the info, it sounds like a all day job.

 

It would only be a 1/2 day job if all your glow plugs come out without difficulty. Which is usually what happens if you are careful. It really is easier than you think. Just like spark plugs, only real skinny ones.

 

Thanks again, I'll replace them this weekend and I'll let you know how I made out