T100 overheating

[JohnY]

Hi All,

I have a '96 T100 V6. It's been a good truck and I have 215K on it. It has started to overheat a bit. I flushed the cooling system, replaced the coolant and replaced the thermostat - all the cheap things first. Still running hot.

Now, I've already replaced a water pump twice, the last time at least 60K ago. The radiator is original. Either water pump or radiator will not be cheap to fix. water pump cheap, labor expensive - what a PITA that job is. Radiator labor cheap, radiator very expensive.

Any tests I can make to see which item is the problem? I don't want to go the replace this, if not, replace that routine.

JohnY

[BamZipPow]

I'm gonna say yer radiator is clogged. Open the cap and take a look inside. You could probably even use a temp reader and see where the hot/cold spots are in yer radiator. Have you been using tap water (like most of us) or have you been using distilled water? You could pull the radiator out and take it to a radiator shop and have them clean it out.

-OR-

You can git a (new) radiator pretty cheap and install it yerself. It's fairly easy.

$190 shipped
$140 shipped...but it's a plastic tank fer what it's worth...
$136 shipped...
$174 shipped...



Just make sure you flush out the system really well before you put the radiator on. Use new hoses and a new cap if it doesn't come with one. And make sure you use the Toyota red coolant...

[kathyricks]

Aftermarket antifreeze + tap water = mineral deposit build inside the radiator core tubes = obstructed coolant flow = tendency to run hot or overheat in both city and highway driving, especially in hot weather.

Toyota Long Life (red colored) antifreeze + distilled water = zero deposit buildup = unlimited radiator life. Ditto Toyota Super Long Life (pink) antifreeze which comes prediluted so you don't need to add water to it.

HOWEVER, before condeming the radiator, manually spin the fan with your hands with the engine shut off. If the fan spins fairly freely (multiple revolutions) before it stops the fan fluid coupling (also called the fan clutch) is shot. If the fan spins with considerable resistance (only one or two
revolutions before it stops) the fluid coupling is OK.

The fluid coupling is fairly inexpensive and easy to replace, but I usually like to remove the radiator for extra working space to remove the coupling.