Well, let me start off with I'm no expert, but I do know a few things and do some of my own repairs. I'm bracing myself for the worst. Want to see what everyone thinks first, and if the worst case scenario is upon me, then what should I do?

I have been going through coolant. Like a gallon every couple hundred miles. Every time I start my truck for the FIRST start of the day (this never happens at any other point throughout the day when I start the truck), 2 minutes down the road I get "P1299," engine temp gauge pegs to HOT instantly, and the truck goes into limp mode. Pull over, turn it off and back on and everything is back to normal. Also, *sometimes* when I pull over I notice the coolant overflows out of the degaus bottle cap. Not a lot, certainly not a gallon's worth, but enough to notice. Temp gauge then reads normal operating temp. This happens like clockwork EVERY TIME I drive the truck for the first time on any given day. I can also hear a "sucking" sound of air under the dash. No apparent leaks. Tried replacing the degaus bottle cap, bleeding the system, checking for leaks, etc. Nothing changed. I still have the thermostat left to try unless this scenario jumps out at someone as not worth it because it's something else. I really like the truck but through a lot of research I fear the head gasket is failing. Also, I should mention recently I have developed the famous "exhaust leak tick" at the passenger side manifold. Great. Now all I need is a spark plug to blow out and I've got three major issues in a matter of a month. What kills me is this truck runs great. Solid truck since the day I bought it 6 months ago, but I've only had it six months and I'm looking at some hefty repairs.

So my questions are, is it worth trying the thermostat or something else, or is it pretty certain I have a bad head gasket?

If I do have a bad head gasket, and with my other issues in mind and the age of the truck (124K miles), what is my best option? Attempt to fix it myself (I'd need to get a hold of a thorough write up and not too sure my skill level is high enough, has anyone done it themselves?), have it repaired professionally, have the engine replaced, or just ditch it? I know selling it is probably the most unpractical as I won't get much for it with a blown head gasket but I'm entertaining all options. I honestly really wanted a diesel and only went for the V10 cause they were cheaper. Any help/insight/suggestions are appreciated. I'm just really bummed

 

I would find another engine or go for the diesel.. thats alot of hard work

 

Dude, change the thermostat. Make sure you test it in boiling water before you install it.

Before you put the new one in, take the old one out, and do a real good cooling system flush.

I had an ex-border patrol excursion with a V-10 that had over 200,000 on the clock, and had the snot beat out of it. ran great. I had the spark plug issue, and I took it to a shop that had the tool, and he fixed it in 20 minutes. Don't be scared of it, just fix it and drive it. Or, if you are scared of it, and want to sell it cheap, PM me.

 

So you think there's good odds it's just the thermostat? I've changed thermostats before and definitely am not scared of attempting that, I was just driving at *if* it was the head gasket, maybe it wouldn't be worth it.

 

Yes, Change the thermostat.
I would eliminate all the simple stuff first. Have you had your coolant cap tested? Be careful where you buy one from, they're cheap, but you want the one with the bigger spring in it.

Head gaskets on a gasser aren't nearly as difficult as on a diesel.

 

Alright since it's like $20 I guess it's worth a try. I think I've eliminated all the other simple stuff. And no I don't buy the cheap stuff believe me everything is a Ford replacement when I work on my truck so the cap is too.