'84 4runner 22r 5sp overheating radiator

[XtraTufgrrll]

Hey ya'll,

My partner ZombieResponseUnit is currently unavailable via internet, so he suggested I post up on here. We've been trying to diagnose this issue for a while now. First, some remedies we've tried: a loose mounting bracket rubbed a hole in the radiator, so it was soldered. While the radiator was out, it was flushed multiple times, and the cooling system was flushed at least 15x. When it overheats, I find it's still losing water somewhere. Zombie thinks the radiator isn't pulling from the reservoir tank - possible pinhole in hose? I'm having to pull over every 30 minutes to re-fill the radiator. Higher speeds and grueling VA heat definitely make it worse. He drove it 4.5 hours in cooler temps with no issue, and I did the same this winter. I'm pulling a lot of hills in 4th on windy roads and not able to put it in 5th. If this isn't resolved soon, we're swapping the motor for a diesel - isuzu c223 or nissan sd22 and/or replacing the radiator. I love this truck and can't give up on her, so all suggestions are appreciated. Sidenote: OEM brass radiator, all factory engine, except radiator hoses, brushes and alternator.

 

[XtraTufgrrll]

By the way, I am not a cucumber. I'm told more posts = the ability to change my avatar. Confirm or deny?

 

[Mudder]

Have you checked fan clutch, replaced the thermostat and water pump and made sure all hoses were fine?

 

[ZombieResponseUnit]

Fan Clutch? The fan spins when the engine is running. The thermostat was removed and was an OEM unit, but seemed to function in a hot water test on the stove. Any how, I replaced the thermostat with a "Fail-safe" unit....POS don't buy one. It's still installed in the truck but when the engine reaches whatever it considers to be "over heating" it locks in the open position. So, currently it's locked open, and I wouldn't consider that the culprit for the over heating/lose of water ether. All hoses are new except the small one from the fill neck to the overflow tank.

I believe the over heating is due to some magical disappearance of water. Where this water is going is the question. It's important to note that the overflow tank is always full. I believe we'll try and change the tube to that soon.

 

[pappy]

Ok, so the tank is always full, but it's not getting returned to the radiator. The only item that would effect that is the cap. Even then, it takes a lot of loss from the radiator to over heat the engine. Cooling systems are not rocket science.

• Look for coolant leaks on the fins of the radiator.
  
• Look for leaks on the upper and lower tanks, especially at the solder.
  
• Look for leaking at the hose clamps.
  
• There is a hard line that runs around the back side of the engine (I think on a 22r), check that.
  
• About the only other place you could be loosing coolant is the heater core. By pass it by looping the supply and return lines on the driver's side of the engine and see of you retain coolant.

But, I would start with the radiator cap first. Because if you are not puking the coolant then you are taking it internally ... read head gasket. Do a compression test.

 

[KLF]

Leak down test.

 

[raevenzero]

That's the answer I thought would come up. That happened to my first 22re.

 

[XtraTufgrrll]

Another issue has been that the battery was boiling over. The alternator and battery have just been replaced, along with the cap and hose to the overflow. So far so good.