1JZ Coolant system problems

[eyesoarer6]

Is the bottom radiator hose suppose to be as hot as the top hose? I had a Freeze plug blow outta my block about 2 weeks ago and now Im thinking that this coolant issue can be the cause.

I got the engine back in and running but noticed that the cooling system is acting strange.

-The temprature gauge is normal
-heater is working
-upper radiator hose hot and pressurized
-bottom radiator hose NOT HOT
-pinhole in radiator
-radiator cap top rusted-cleaned off


After driving the car 20 miles I looked under the hood and heard/felt that my top radiator hose was boiling.

Can a bad Water Pump cause this? On the 1JZs where is the bleeder valve for the coolant? WP is not leaking from the nipple, how can I tell if its bad? I have a feeling that my coolant system is restricted and not recirculating, what are tests to check this out?

 

[Boost_happy]

Yoy might try changing the thermostat and make sure its an OEM one witht he little hole in the ring. bought one from the local auto parts store (car quest) and it ran way too hot and wouldnt open, my guess because it didnt have that little hole to let the air bleed through. i ended up putting the old toyota one back in and it works fine

 

[eyesoarer6]

I changed the t-stat out 3 times. A buddy of mine suggested that I drill a tiny hole in the t-sat to see if it helps. It did, the lower rad-hose got hotter and pressurized. I took the WP out to inspect it. All looked good, there wasnt any play in the fins. My brother in law told me to take the rad cap off to look if the coolant was flowing-moving. Coolant wasnt flowing, can this be a bad WP?

 

[mkiiichip]

Why are you driving with a pinhole in the radiator? Dont you think you should fix that?

 

[f00g00]

Try running without the thermostat and if the flow is good then the water pump is working. The thermostat sounds like its not opening and you might have clogs in the rad. You might want to do a power flush too. For sure get the rad fixed and rodded out and run with an oem thermostat.

 

[OneJArpus]

Replace the following:
1. Radiator
2. Radiator Cap
3. Thermostat
4. FLUSH SYSTEM

Recheck system, while filling if you do not see it "flow" or it runs hot take out the Water pump and inspect the blades. If something is wrong;

5. Water pump & Flush again.