03 4.7 Tundra overheated

So where do I start I recently purchased in 03 Toyota Tundra 4.7 off a co-worker for fairly cheap. Get it home had some starting issues like it wouldnt once i got home. Found this forum, and it led me to replace the battery cables that fixed the issue that or redoing all the grounds one of the two.Now cut to 3 weeks later. I flushed cooling system when i did the tune up. It overheated sunday on the way to work. After work I added water and coolant to radiator. And drove it home. Drove ok until i got to about 50 mph. Then it got rough. Like loss of power. It wasnt getting hot so i tried to see if it would power thru the stall. It would power thru but happened everytime i got to 50. I went straight home about 10 miles. A day later went to check out the system and make sure i didnt do significant damage like warp a head. No plumes of white smoke so i believe heads are fine. I had it pegged though. I wont lie. It was 5am and i didnt notice until it was buried. Some moisture dripping from exhaust, but no white smoke. Oil didnt seem milky on dipstick or inside of cap. Filled radiator again and let it idle in driveway. Water poured out of bottom of radiator. I need to pull that now and make sure its not a busted line. I am really wondering is there a way to check water pump without watching the flow in radiator. Also what caused the power loss at 50? Thermostat stuck closed maybe? I plan on replacing thermostat radiator and hoses. I really cant afford the water pump, but ill park it until I can if i need to. Any help from you experts would be appreciated. Im not a mechanic, but I have a little common sense. Enough that I have been driving 24 years and never took a vehicle to a mechanic. Managed just fine on my own. The power loss thing has me worried though. If its a head I need to fix that before i drive it anymore i know.

 

Check the radiator tanks (top and bottom of the rad), plastic tanks will split, and when they close it looks like a hairline.

if its due for sparkplugs, pull the plugs and crank the starter to see if theres any water in the cylinders. A compression test wouldnt hurt while you’re in there, and can be rented from a parts store.

any codes?

 

I put new plugs and coils on when i tuned it up, but i will check that to make sure. Rings could still be good on cyl so oil seems ok? Also the radiator is leaking for sure bottom somewhere. Its just been raining so havent been back out to check it out.No codes no new lights nothing. Really seems like a bad radiator. The power loss thing has me worried though, but like i said oil wasnt milky and no white smoke

 

You mentioned the power loss was at 50 mph. Below 50 did it drive normal? Did you notice by chance if it let you rev to a certain rpm before cutting? Sounds like it may have been hitting limp mode to protect itself.

 

Did you burp the system when you flushed the radiator? Did you let it get up to temp and run the heater once fluid was replaced? You should have been able to tell when the thermostat opened.

 

So I changed radiator thermostat and hoses. It doesn't overheat or anything, but runs pretty rough. Ya I burped system by letting it warm up and popping cap 2 separate times. It still runs rough though.

 

No more power loss at 50 though

 

Tires are pretty rough on it though so I wonder if that's causing some of my problem

 

You mean the engine runs rough or the ride is rough?

 

I mean it has a good idle but once I start driving I can feel it the engine rides rough I mean the truck rides a little rough too I mean it's an 03 but yeah it's something rough in the engine like it almost feels like a broken motor mount but I don't see how that would have happened from overheating. The acceleration is smooth though it doesn't jump around it doesn't shift hard just rough it feels rough hard to explain it went from a good riding truck to an old beater. I just wonder what overheating could have damaged that would cause that the mass airflow sensor or something I'm taking shots in the dark

 

I'm going to do the compression test tomorrow if I can get one from an auto parts store follow up

 

Did it run okay before new plugs and coils?

 

It ran great until it overheated. That morning it was idling high. Then got hot otw to work.

 

New plugs. Compression test ok. Still missing really bad. Gonna do coils and see if that fixes it. The plugs were pretty bad

 

No codes?

What was wrong with the plugs? Burnt? Oil fouled?

 

Plugs were dirty as hell old corroded. oil seems fine. Now it has the miss and smoking out of exhaust. I am assuming from unburned fuel. When coils get in I'll switch those out. Hope it fixes it. Any ideas would be appreciated. But it did pass compression test. 185-195

 

Miss on which cylinders, specifically, has it set a code to say?

If you know which cylinders, try to swap coils with adjacent ones, clear codes, see if it migrates before you drop money on new Denso coils (don't buy other brands; don't buy on scamazon or fleabay, don't bother replacing all coils at once).

You probably don't want to be running the engine a lot right now. Last thing you want to do is foul up your cats in the process, then need to add new cats to the list.

 

P0304 is the code misfire on 4 few secondary and random misfires

 

And it's only on 4? What happens if you swap the coil on 4 with the coil on 2 or 6 cylinder? Does the code move after you clear things out?

If so, it's the coil. Order new Denso coil pack from RockAuto. If not, it could be the plug or the wiring most likely, if not, something more sinister.

 

What color ?
If white, my first thought is possible blown head gasket given overheating issues you've experienced along with misfires.