Assuming that you have some glow plugs burned out, the more you use your truck without all 8 glow plugs working, the faster the rest will burn out. You will soon be without any working glow plugs.
If I can put it off, even a month or two, it would help. A year is a stretch, I admit. You are supposed to replace all 8 at the same time anyway, so if another one or two go, so be it. They all get replaced anyway.
But it just depends on how soon the others would burn out, I suppose. It's almost like I have none now, the way it acts in the 40s or below, since they come on for all of 3 seconds maximum. It's nowhere near enough. I have to crank it a lot, with breaks in between to give the starter rests, until it finally fires up. That's not good for the engine, I'm sure.
Then I have to also give it a little throttle too. The temp sensor by the thermostat pipe has a broken off blade. I bought a new sensor for it months ago, but it didn't matter in summer so I put it off. When I went to finally put it in, I realized that you have to pull the vacuum pump, alternator and their bracket, drain half the coolant, remove the thermostat to radiator hose pipe and then you can get at the sensor. That stupid pipe is right in the way!
But back to glow plugs .... I will be getting the proper Motorcraft ZD9 ones, since I've read that cheaper ones swell and can break off when trying to get them out. I don't know what it has in it right now, so... that's something else to worry about until all 8 come out without breaking.
If I can spend $10-15 to patch it up for a month or two, that's ideal financially right now. I will be heading to Arizona for the winter, so if they burn out enough while I'm there, so be it. I can order the plugs from Amazon and install them while I'm there. It seems to largely be favored by folks here to have a manual switch ANYWAY, so it's not exactly wasted money.
I'm trying to get away from kicking things down the road credit wise. That's why I'm having to pay so much on credit right now to avoid interest on 6-month-no-interest promotions. I kept stacking more up saying "I'll pay it later, it's no problem" but then something else came up (such as the alternator, the vacuum pump and pulley puller tool from Napa, and a set of tires...) so I need to try to avoid excessive spending if at all possible right now. Yes, $75 to me is "excessive" at the moment, considering it's going to cost me about $270, give or take, to get down to Arizona from here. Once I'm there, I'll be there for several months, so I'll be able to afford the plugs in December.
I've been bumming around a city in Washington for 2.5 months now (as in, street parking overnight), and so far I haven't been bugged any but I can't rely on that lasting forever. Especially with an out of state license plate. Plus its getting really rainy here now, which isn't something my dog enjoys since she can't get outside much.
So basically, a cheap patch to last me a month or two is all I need at the moment.