I spent the day working on it again and this is what's going on:

New upper and lower hoses, new fail-safe thermostat, new water pump, new overflow/radiator cap, new fan clutch, new radiator, flushed heater core twice, flushed the entire system again, filled with 50/50 mix of anitfreeze and distilled water. From what I can tell, there is nothing left to replace, flush, adjust, etc.

So, I'm gonna try and drive it for the rest of the weekend and see what happens. I'm hoping for the best but to be honest with you, I'm not convinced that the problem is fixed. I don't know what else there is to fix/replace but for some reason I just see it happening again. But I will update this thread in a week or two, or sooner if it blows up tomorrow, so that there is some info for anyone who might have the same problem in the future. Thanks for the help guys. I'll keep you posted.

Oh, and BigBadJohn, there was a long conversation a couple of weeks ago about whether or not it was the work of the devil...with the whole "the power of Christ compels you" and everything.

And to tell you all how much of a pain the *** this problem has been and why I am so tired of working on it and throwing money at it...It was a year ago yesterday that the problem first presented itself. I've been fighting this crap for a year!!!

 

Hmmm, sounds like you've covered the bases quite well and several times over.

Is the water pump actually moving coolant? Not sure how the best way would be to verify this. One thought would be to remove the thermostat and watch through the radiator cap opening to see if coolant is moving. If that can't readily be seen, another messier thought would be to remove the thermostat, leave the upper hose connection undone and see if the pump is pushing coolant out.

Is the thermostat installed correctly, not upside-down? Don't mean to offend - just relating to a long line of personal experiences here getting tripped up on some of the simplest stuff.

As BigBadJon alluded to - is there good airflow through the radiator, no obstructions at the condenser, fan is moving a lot of air through the radiator core and not just beating the air around?

When the boilovers occur, is the radiator hot-hot? A 50/50 mix under 15psi pressure shouldn't boil until 267degF. If coolant isn't moving, could see the coolant boiling in the engine - but if there were little or no flow, the radiator would be significantly cooler.

Trying to determine whether the heat is not being transferred out of the engine due to poor coolant flow, or whether the heat is not able to be released from the radiator due to poor airflow.

Hang in there - every problem has a solution, and the problem always seems easy when one already knows the answer.

 

My truck had a bad head gasket. This was causing the cooling system to malfunction. It was pressurising the radiator. Also, my radiator was bad. There's a test you can get from somewhere that involves placing a liguid into a sample of the radiator water and if it turns a certain color, you have combustion leaking into the cooling system. I hope this isn't what you have because its a major repair. But I had replaced the thermostat and water pump and that didn't help. I just got the truck back today and I think the main problem is fixed but the temp gauge isn't working. I have to take it back monday. They think the sending unit sprung when it got hot.

 

Two weeks and no issues yet. Hoping it's fixed but I still don't trust it.

 

Sorry to hear about all of your problems, a year, thats no good. Hope everything continues to be OK, like you, I have my doubts. But lets hope. By the way, when doing all this work and rework, how much coolant did it take to fill the system? Also is the heater performing correctly? Asking this for the obvious reason, is it full of coolant? Good luck.

 

Yeah, it's full of coolant. Checked a couple of times. Can't say for sure exactly how much I put in because each time I worked on it was right after it overheated. So I lost a lot of coolant from it boiling over, pulled some parts, lost some more coolant, replaced parts, added coolant, ran until thermostat opened, added coolant, lather, rinse, repeat. So, depending on the work I was doing the heater core was still full, or the block was full, or whatever.

But, it's been a few more days and it's still running. I just want to keep the thread updated because I hate when someone has a problem like this, posts it up asking for advice and then figures it out and never posts back up with what they did to fix it.

Thanks again guys for all your help. I'll keep you updated.

 

Another week and still running. Although, now I am getting the P0171 and P0174 codes for Banks 1 and 2 running lean. Gonna check that out tomorrow.

 

Try By-passing the heater core if you can, hook up a temporary hose from engine block and see what happens.If truck doesn`t over heat, you know you either have a bad core or maybe something blocking core. From there, maybe check the t-stat the old fashion way to see if it opens,hold it with vise grips and dip it in some Boiling water to see if it opens.

 

I hope you have it fixed. I certainly feel for you with all the time, money and frustration you went through. Good luck!

 

Another couple of hundred miles and she's still running. As for the codes...new fuel filter, cleaned MAF sensor, sealed some gaps between the MAF and the throttle body and have yet to get the check engine light again. I tried to pull the O2 sensors but couldn't get them loose to save my life. Hopefully they are not the problem.