My 120y is running hot about 2/3 up to the H mark. I would like to get a bit of feedback on troubleshooting this. It has the stock radiator which doesnt appear to be in great condition - many of the fins are crumbling away and there's a few leaks. I happen to have a Gemini radiator that I thought I would use instead.

Should I just replace the radiator and be done with it, or check the whole cooling system while I'm at it? I'm guessing I should be doing the following things:

Check Thermostat (use a thermometer to check opening? )
Inspect water pump (how do I do this?)
Flush engine block ?

Also, if I'm removing the water pump and thermostat should I be obtaining new gaskets?

Just replace the radiator. That's most likely the entire cause if some of the fins have crumbled away.

Since you'll be draining coolant, flush it engine (just run garden hose the hoses. If you remove the thermostat it will be more effective.

Fill with new coolant/water mix according the instructions on the coolant container.

Thanks DD. So it should be - Draining coolant, remove radiator, remove thermostat, flush with garden hose in bottom hose, install radiator & coolant..?

Should I be turning heater to hot?

Just have the heater valve open... should do the trick

To test the water pump:

1. Check for play: remove the fan belt then see if you can rock the fan back and forth. There should be zero play. If the bearing is worn it should be replaced before it starts leaking.

2. Check for leak. There is a weep hole on the bottom of the shaft area if you see leakyness there replace the pump



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I had the same with mine when i had the standard A12... The thermostat was faulty along with a faulty temp sender.

install gemi one, while your at it do the thermostat too with a new one.

should be fine, if not will need further investigation

I just pulled the thermostat and chucked it in boiling water. I did not observe any change as the water got up to boil. The thermostat also looks broken - cracked along the top - so I guess its stuffed.

Excellent. It's an easy solution.

With the crumbled fins it still may go past the 1/2 mark occasionally but that won't hurt anything.

do the gemini rad swap while your at it- save that boiling water to heat the hoses so they slip over the rad inlet and outlets- or microwave the hose for 3-6sec to soften it up slightly.