87 toyota truck head gasket leak. new thermostat,and radiator. Rapid temp fluctuation red to norm?

Check your thermostat,coolant in radiator,Water pump,Make sure it's circulating. Check radiator fan.Check your catalytic converter..If its clogged up your car will run hot.Hopefully the leak is a freeze plug and not a cracked head.. Check oil... Make sure water is not mixing with oil..If your car is back firing or slow on acceleration...it's the Catalytic converter in front of muffler. If it is don't throw it away they can be sold for scrap

Dirty coolant and loss, is likely a head gasket. Can put the system under a vacuum and see if it holds -28 lbs vacuum. Should hold indefinitely if good.

What you are describing is a cooling system low on coolant or a sticking thermostat.
I might leave the thermostat out and drive it a few days to see what happens. There could be something in the system that is restricting flow, or it could still be low on coolant.
Its possible something is not right with air flow thru the radiator or the fan clutch. There could be a restriction in the ac condenser.

did you change the thermostat? you may have to have the head gaskets tested.

Did u end up finding out what the problem was?

First check if you have any leaks in the cooling system , then check if level is correct(radiator and expansion tank , check level when car is cold , never open radiator when it's hot).
Then verify operation of radiator fan , if it's electrical fan it should comes on when temp. goes over normal,
if it's a clutch fan- it should pick up a speed and be more loud. If fan is not on and engine is starting overheating , check upper and lower radiator hoses.
If upper hose hot and lower hose cold or warm then you might have stuck close or prtially closed thermostat , difference between lower and upper hoses when t/stat works ok is about 10-15 degrees,
not really noticeable for hand.So if you don't feel a lot of difference between hoses temp. , and fan is not on , check fan or fan clutch itself.
If lower hose cold , replace thermostat and purge system.
If everything above is working properly , and it's still overheating , you may have bad water pump or head gasket.

you have an intake or head gasket leaking internally..

Hi,

Firstly, ensure you have the required 'mixture' of coolant/water (must have required coolant).

Second, I would recommend you re-test all the cooling system sensors again (make sure they're within specifications), in case a new one is faulty.

Third, ensure the new thermostat was of the correct temp setting (they all differ), so that it opens at the required time. Most cooling systems operate within 90 - 100degC.

Fourth, make sure the radiator (and associated hoses) aren't blocked.

If your temp gauge is reading higher than normal, but NOT in the danger zone...then this can be considered normal (especially if you've replaced with new components) and nothing to be concerned about.

However, if the temp gauge IS in the danger zone....then this suggests the coolant is not flowing through the cooling system properly.

If all above components test ok, then it's possible your water pump may not be pumping enough volume.

Cheers,

It is your radiator. Too stopped up for a flush to do any good. Cooler temps in the winter will keep it cooling better versus hot summer temps.

it is possible it might have a cracked or blown gasket head! simple trick check the oil to see if its milky colored if it is then its your head or head gasket if not let me know thanks josh........